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[GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem [message #327671] Tue, 02 January 2018 11:24 Go to next message
BobDunahugh is currently offline  BobDunahugh   United States
Messages: 2465
Registered: October 2010
Location: Cedar Rapids, IA
Karma: 11
Senior Member
Our first 78 Royale came with a Digi panel. I knew my engine temps under all conditions. Then the fire. Bought another 78 Royale. But the Digi panel wasn't being made at that time. Both GMC stock temp gauges read the same. But it didn't take long before I had a feeling that this second Royale was running hotter. No boil overs. Just did't feel right. So on our next trip. I raise the engine cover several times to check the engine temp sender with an inferred temp reader. Found that this Royale was generally operating about 10 degrees hotter with the stock gauge reading in the normal range as compared to our first GMC. Jim at Applied GMC had started producing the Digi panel. And had them at the GMCMI rally that we were going too. Installed the Digi panel at the rally. On the way home the panel also confirmed what I thought. So why the running hotter? Checked the thermostat. It was a good operating 180. But I changed to a proper 195. Fan clutch? Maybe. Well Jim K at Applied started selling a fan clutch that is controlled by engine block sensors. I liked the idea that this system is more proactive in controlling engine heat buildup. Plus I can turn the clutch on for the fan by a dash mounted switch when I want. So I bought that fan clutch at the GMCMI rally. I had recently put on an aluminum 307 Olds intake manifold. So I knew the engine was clean inside. Did the engine have a car water pump? Don't know. But even if there's a car pump. That's not the real big problem. Next I drained the radiator. Put my inspection camera in the radiator. Radiator's my problem. Looked heavily corroded at the crossover tubes. Going to put the radiator from the burned GMC in soon. Probably check/change water pump anyway while I'm doing other work in that area. Installing more gauges to look at isn't the best idea in my opinion. One. I want to be looking at the road for safe driving. Two.The Digi panel has gages. But it's audible alarm is your best engine/trans protection.

Bob Dunahugh 78 Royale
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Re: [GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem [message #327675 is a reply to message #327671] Tue, 02 January 2018 13:49 Go to previous messageGo to next message
Mike Kelley is currently offline  Mike Kelley   United States
Messages: 467
Registered: February 2017
Karma: -2
Senior Member
Bob D.:
I like your thought process and how you put things in simple terms, so we non mechanics can follow along.
Thanks for being you and Happy New Beginnings to you and Linda - have a Gr8 2018.
Mike/The Corvair a holic

Sent from my iPhone

> On Jan 2, 2018, at 11:24 AM, Bob Dunahugh wrote:
>
> Our first 78 Royale came with a Digi panel. I knew my engine temps under all conditions. Then the fire. Bought another 78 Royale. But the Digi panel wasn't being made at that time. Both GMC stock temp gauges read the same. But it didn't take long before I had a feeling that this second Royale was running hotter. No boil overs. Just did't feel right. So on our next trip. I raise the engine cover several times to check the engine temp sender with an inferred temp reader. Found that this Royale was generally operating about 10 degrees hotter with the stock gauge reading in the normal range as compared to our first GMC. Jim at Applied GMC had started producing the Digi panel. And had them at the GMCMI rally that we were going too. Installed the Digi panel at the rally. On the way home the panel also confirmed what I thought. So why the running hotter? Checked the thermostat. It was a good operating 180. But I changed to a proper 195. Fan clutch? Maybe. Well Jim K at Applied started selling a fan clutch that is controlled by engine block sensors. I liked the idea that this system is more proactive in controlling engine heat buildup. Plus I can turn the clutch on for the fan by a dash mounted switch when I want. So I bought that fan clutch at the GMCMI rally. I had recently put on an aluminum 307 Olds intake manifold. So I knew the engine was clean inside. Did the engine have a car water pump? Don't know. But even if there's a car pump. That's not the real big problem. Next I drained the radiator. Put my inspection camera in the radiator. Radiator's my problem. Looked heavily corroded at the crossover tubes. Going to put the radiator from the burned GMC in soon. Probably check/change water pump anyway while I'm doing other work in that area. Installing more gauges to look at isn't the best idea in my opinion. One. I want to be looking at the road for safe driving. Two.The Digi panel has gages. But it's audible alarm is your best engine/trans protection.
>
> Bob Dunahugh 78 Royale
> _______________________________________________
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Re: [GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem [message #327688 is a reply to message #327671] Tue, 02 January 2018 17:08 Go to previous messageGo to next message
BobDunahugh is currently offline  BobDunahugh   United States
Messages: 2465
Registered: October 2010
Location: Cedar Rapids, IA
Karma: 11
Senior Member
Mike K. Thanks. I think this is more of a problem then is generally thought. I pull higher GVW's more then most. And never had any add on items installed on our 403 GMC. Radiator inspections on attendees GMC's. Might make for a good tech session at the GMCMI rally in Tucson. Line them up, and start checking with my inspection camera. Drain pan, funnel, and the camera. At a cost of FREE. Good idea, or not. Any input out there? Bob Dunahugh






Our first 78 Royale came with a Digi panel. I knew my engine temps under all conditions. Then the fire. Bought another 78 Royale. But the Digi panel wasn't being made at that time. Both GMC stock temp gauges read the same. But it didn't take long before I had a feeling that this second Royale was running hotter. No boil overs. Just didn't feel right. So on our next trip. I raise the engine cover several times to check the engine temp sender with an inferred temp reader. Found that this Royale was generally operating about 10 degrees hotter with the stock gauge reading in the normal range as compared to our first GMC. Jim at Applied GMC had started producing the Digi panel. And had them at the GMCMI rally that we were going too. Installed the Digi panel at the rally. On the way home the panel also confirmed what I thought. So why the running hotter? Checked the thermostat. It was a good operating 180. But I changed to a proper 195. Fan clutch? Maybe. Well Jim K at Applied started selling a fan clutch that is controlled by engine block sensors. I liked the idea that this system is more proactive in controlling engine heat buildup. Plus I can turn the clutch on for the fan by a dash mounted switch when I want. So I bought that fan clutch at the GMCMI rally. I had recently put on an aluminum 307 Olds intake manifold. So I knew the engine was clean inside. Did the engine have a car water pump? Don't know. But even if there's a car pump. That's not the real big problem. Next I drained the radiator. Put my inspection camera in the radiator. Radiator's my problem. Looked heavily corroded at the crossover tubes. Going to put the radiator from the burned GMC in soon. Probably check/change water pump anyway while I'm doing other work in that area. Installing more gauges to look at isn't the best idea in my opinion. One. I want to be looking at the road for safe driving. Two. The Digi panel has gages. But it's audible alarm is your best engine/trans protection.

Bob Dunahugh 78 Royale
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Re: [GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem [message #327689 is a reply to message #327688] Tue, 02 January 2018 18:27 Go to previous messageGo to next message
Mike Kelley is currently offline  Mike Kelley   United States
Messages: 467
Registered: February 2017
Karma: -2
Senior Member
Bob:
I really like your idea for the tech session. Another way to help fellow GMCers! Assuming we get there (we are planning on it), I would like my Dream Machine checked in this way - I also would be interested in assisting you in this endeavor if you could use an amateur!!!
Mike/The Corvair a holic

Sent from my iPhone

> On Jan 2, 2018, at 5:08 PM, Bob Dunahugh wrote:
>
> Mike K. Thanks. I think this is more of a problem then is generally thought. I pull higher GVW's more then most. And never had any add on items installed on our 403 GMC. Radiator inspections on attendees GMC's. Might make for a good tech session at the GMCMI rally in Tucson. Line them up, and start checking with my inspection camera. Drain pan, funnel, and the camera. At a cost of FREE. Good idea, or not. Any input out there? Bob Dunahugh
>
>
>
>
>
>
> Our first 78 Royale came with a Digi panel. I knew my engine temps under all conditions. Then the fire. Bought another 78 Royale. But the Digi panel wasn't being made at that time. Both GMC stock temp gauges read the same. But it didn't take long before I had a feeling that this second Royale was running hotter. No boil overs. Just didn't feel right. So on our next trip. I raise the engine cover several times to check the engine temp sender with an inferred temp reader. Found that this Royale was generally operating about 10 degrees hotter with the stock gauge reading in the normal range as compared to our first GMC. Jim at Applied GMC had started producing the Digi panel. And had them at the GMCMI rally that we were going too. Installed the Digi panel at the rally. On the way home the panel also confirmed what I thought. So why the running hotter? Checked the thermostat. It was a good operating 180. But I changed to a proper 195. Fan clutch? Maybe. Well Jim K at Applied started selling a fan clutch that is controlled by engine block sensors. I liked the idea that this system is more proactive in controlling engine heat buildup. Plus I can turn the clutch on for the fan by a dash mounted switch when I want. So I bought that fan clutch at the GMCMI rally. I had recently put on an aluminum 307 Olds intake manifold. So I knew the engine was clean inside. Did the engine have a car water pump? Don't know. But even if there's a car pump. That's not the real big problem. Next I drained the radiator. Put my inspection camera in the radiator. Radiator's my problem. Looked heavily corroded at the crossover tubes. Going to put the radiator from the burned GMC in soon. Probably check/change water pump anyway while I'm doing other work in that area. Installing more gauges to look at isn't the best idea in my opinion. One. I want to be looking at the road for safe driving. Two. The Digi panel has gages. But it's audible alarm is your best engine/trans protection.
>
> Bob Dunahugh 78 Royale
> _______________________________________________
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Re: [GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem [message #327693 is a reply to message #327689] Tue, 02 January 2018 20:15 Go to previous messageGo to next message
thesmith is currently offline  thesmith   United States
Messages: 589
Registered: February 2015
Location: Cary, NC
Karma: 6
Senior Member
Good, idea, and as a bonus the coolant gets changed, which is likely long overdue Smile

Cary, NC 1978 Center Kitchen Royale.
Re: [GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem [message #327698 is a reply to message #327693] Wed, 03 January 2018 09:36 Go to previous messageGo to next message
powwerjon is currently offline  powwerjon   United States
Messages: 849
Registered: March 2013
Karma: -2
Senior Member
Pete,
The factory temp gauge sender has caused a number of issues. The range indicated is really not useful or a good indication of actual engine temp and you can damage an engine thinking that you have been a safe zone. Go to the following information:

http://gmcmotorhome.info/engine.html#sender

If you are running the stock radiator you should be running a 9# cap and they are still available and never more than a 10# cap. You can damage the radiator by using any higher pressure rated cap. The aluminum radiators typically use a 14-16# rated cap because they are built differently and do not expand and contract like the stock one would with a higher rated cap.

http://gmcmotorhome.info/engine.html#cap

Regards,

J.R. Wright
GMC GreatLakerTech Editor
78 Buskirk 30' Stretch
75 Avion Under Reconstruction
Michigan (On Location in Tucson)


> On Jan 2, 2018, at 7:15 PM, Pete Smith wrote:
>
> Good, idea, and as a bonus the coolant gets changed, which is likely long overdue :)
> --
> Cary, NC
>
> 1978 Center Kitchen Royale.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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Re: [GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem [message #327699 is a reply to message #327698] Wed, 03 January 2018 09:45 Go to previous messageGo to next message
Keith V is currently offline  Keith V   United States
Messages: 2337
Registered: March 2008
Location: Mounds View,MN
Karma: 0
Senior Member
I replaced the OEM temp sender. That thing is terrible.


Go to NAPA and get a TS-6469 sender and it will show:
1/4= 180 degrees,
1/2 = 215 degrees,
3/4 = 240 degrees, and
H = 255 degrees.

http://gmcmotorhome.info/engine.html#sender
[http://gmcmotorhome.info/figs/dists.jpg]

ENGINE - GMC MOTORHOME INFORMATION
gmcmotorhome.info
Supplementing the September 2007 issue of GMC Motorhome News, Sam Carson of Indian Harbour Beach, Florida, has advised that new American Petroleum Institute (API) SM ...





________________________________
From: Gmclist on behalf of John Wright
Sent: Wednesday, January 3, 2018 9:36:18 AM
To: gmclist@list.gmcnet.org
Subject: Re: [GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem

Pete,
The factory temp gauge sender has caused a number of issues. The range indicated is really not useful or a good indication of actual engine temp and you can damage an engine thinking that you have been a safe zone. Go to the following information:

http://gmcmotorhome.info/engine.html#sender

If you are running the stock radiator you should be running a 9# cap and they are still available and never more than a 10# cap. You can damage the radiator by using any higher pressure rated cap. The aluminum radiators typically use a 14-16# rated cap because they are built differently and do not expand and contract like the stock one would with a higher rated cap.

http://gmcmotorhome.info/engine.html#cap

Regards,

J.R. Wright
GMC GreatLakerTech Editor
78 Buskirk 30' Stretch
75 Avion Under Reconstruction
Michigan (On Location in Tucson)


> On Jan 2, 2018, at 7:15 PM, Pete Smith wrote:
>
> Good, idea, and as a bonus the coolant gets changed, which is likely long overdue :)
> --
> Cary, NC
>
> 1978 Center Kitchen Royale.
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org


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Keith Vasilakes
Mounds View. MN
75 ex Royale GMC
ask me about MicroLevel
Cell, 763-732-3419
My427v8@hotmail.com
Re: [GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem [message #327702 is a reply to message #327698] Wed, 03 January 2018 10:28 Go to previous messageGo to next message
Mike Kelley is currently offline  Mike Kelley   United States
Messages: 467
Registered: February 2017
Karma: -2
Senior Member
Thanks John W.:
Good info and well stated.
I love it when you knowledgeable guys share good info so directly that a non mechanic like myself can learn from it.
Have Gr8 2018

Sent from my iPhone

> On Jan 3, 2018, at 9:36 AM, John Wright wrote:
>
> Pete,
> The factory temp gauge sender has caused a number of issues. The range indicated is really not useful or a good indication of actual engine temp and you can damage an engine thinking that you have been a safe zone. Go to the following information:
>
> http://gmcmotorhome.info/engine.html#sender
>
> If you are running the stock radiator you should be running a 9# cap and they are still available and never more than a 10# cap. You can damage the radiator by using any higher pressure rated cap. The aluminum radiators typically use a 14-16# rated cap because they are built differently and do not expand and contract like the stock one would with a higher rated cap.
>
> http://gmcmotorhome.info/engine.html#cap
>
> Regards,
>
> J.R. Wright
> GMC GreatLakerTech Editor
> 78 Buskirk 30' Stretch
> 75 Avion Under Reconstruction
> Michigan (On Location in Tucson)
>
>
>> On Jan 2, 2018, at 7:15 PM, Pete Smith wrote:
>>
>> Good, idea, and as a bonus the coolant gets changed, which is likely long overdue :)
>> --
>> Cary, NC
>>
>> 1978 Center Kitchen Royale.
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> _______________________________________________
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> Unsubscribe or Change List Options:
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Re: [GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem [message #327703 is a reply to message #327698] Wed, 03 January 2018 10:30 Go to previous messageGo to next message
Mike Kelley is currently offline  Mike Kelley   United States
Messages: 467
Registered: February 2017
Karma: -2
Senior Member
To John W.:
Oops - hit send button B 4 I identified myself.
Have a Gr8 2018.
Mike/The Corvair a holic (also a GMC 6 Wheeler)

Sent from my iPhone

> On Jan 3, 2018, at 9:36 AM, John Wright wrote:
>
> Pete,
> The factory temp gauge sender has caused a number of issues. The range indicated is really not useful or a good indication of actual engine temp and you can damage an engine thinking that you have been a safe zone. Go to the following information:
>
> http://gmcmotorhome.info/engine.html#sender
>
> If you are running the stock radiator you should be running a 9# cap and they are still available and never more than a 10# cap. You can damage the radiator by using any higher pressure rated cap. The aluminum radiators typically use a 14-16# rated cap because they are built differently and do not expand and contract like the stock one would with a higher rated cap.
>
> http://gmcmotorhome.info/engine.html#cap
>
> Regards,
>
> J.R. Wright
> GMC GreatLakerTech Editor
> 78 Buskirk 30' Stretch
> 75 Avion Under Reconstruction
> Michigan (On Location in Tucson)
>
>
>> On Jan 2, 2018, at 7:15 PM, Pete Smith wrote:
>>
>> Good, idea, and as a bonus the coolant gets changed, which is likely long overdue :)
>> --
>> Cary, NC
>>
>> 1978 Center Kitchen Royale.
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

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Re: [GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem [message #327704 is a reply to message #327688] Wed, 03 January 2018 10:43 Go to previous messageGo to next message
BobDunahugh is currently offline  BobDunahugh   United States
Messages: 2465
Registered: October 2010
Location: Cedar Rapids, IA
Karma: 11
Senior Member
Pete. That's a good idea. The owner could just bring new antifreeze. Flush, and then put the new antifreeze in. Have to find out what's the best way to dispose the old antifreeze there. We'd also have to have a pre event registration list to know what to be prepared for. Bob Dunahugh



Mike K. Thanks. I think this is more of a problem then is generally thought. I pull higher GVW's more then most. And never had any add on items installed on our 403 GMC. Radiator inspections on attendees GMC's. Might make for a good tech session at the GMCMI rally in Tucson. Line them up, and start checking with my inspection camera. Drain pan, funnel, and the camera. At a cost of FREE. Good idea, or not. Any input out there? Bob Dunahugh






Our first 78 Royale came with a Digi panel. I knew my engine temps under all conditions. Then the fire. Bought another 78 Royale. But the Digi panel wasn't being made at that time. Both GMC stock temp gauges read the same. But it didn't take long before I had a feeling that this second Royale was running hotter. No boil overs. Just didn't feel right. So on our next trip. I raise the engine cover several times to check the engine temp sender with an inferred temp reader. Found that this Royale was generally operating about 10 degrees hotter with the stock gauge reading in the normal range as compared to our first GMC. Jim at Applied GMC had started producing the Digi panel. And had them at the GMCMI rally that we were going too. Installed the Digi panel at the rally. On the way home the panel also confirmed what I thought. So why the running hotter? Checked the thermostat. It was a good operating 180. But I changed to a proper 195. Fan clutch? Maybe. Well Jim K at Applied started selling a fan clutch that is controlled by engine block sensors. I liked the idea that this system is more proactive in controlling engine heat buildup. Plus I can turn the clutch on for the fan by a dash mounted switch when I want. So I bought that fan clutch at the GMCMI rally. I had recently put on an aluminum 307 Olds intake manifold. So I knew the engine was clean inside. Did the engine have a car water pump? Don't know. But even if there's a car pump. That's not the real big problem. Next I drained the radiator. Put my inspection camera in the radiator. Radiator's my problem. Looked heavily corroded at the crossover tubes. Going to put the radiator from the burned GMC in soon. Probably check/change water pump anyway while I'm doing other work in that area. Installing more gauges to look at isn't the best idea in my opinion. One. I want to be looking at the road for safe driving. Two. The Digi panel has gages. But it's audible alarm is your best engine/trans protection.

Bob Dunahugh 78 Royale
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Re: [GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem [message #327707 is a reply to message #327704] Wed, 03 January 2018 11:05 Go to previous messageGo to next message
emerystora is currently offline  emerystora   United States
Messages: 4442
Registered: January 2004
Karma: 13
Senior Member
The radiator cap should also be tested. Most only last about 2 years. The spring weakens as it opens and closes thousands of times on a trip. And the rubber seals deteriotate over time.

I have a Stant pressure gauge that I use. It can also pressurize the radiator cold so it can be checked for leaks, bad hose connections, etc. I can bring that tester to the rally

I once made a bet at a GMC Classics rally that at least half of the motorhome there would have bad radiator caps. Of the 24 tested 17 had bad caps!

Emery Stora

> On Jan 3, 2018, at 9:43 AM, Bob Dunahugh wrote:
>
> Pete. That's a good idea. The owner could just bring new antifreeze. Flush, and then put the new antifreeze in. Have to find out what's the best way to dispose the old antifreeze there. We'd also have to have a pre event registration list to know what to be prepared for. Bob Dunahugh
>
>
>
> Mike K. Thanks. I think this is more of a problem then is generally thought. I pull higher GVW's more then most. And never had any add on items installed on our 403 GMC. Radiator inspections on attendees GMC's. Might make for a good tech session at the GMCMI rally in Tucson. Line them up, and start checking with my inspection camera. Drain pan, funnel, and the camera. At a cost of FREE. Good idea, or not. Any input out there? Bob Dunahugh
>
>
>
>
>
>
> Our first 78 Royale came with a Digi panel. I knew my engine temps under all conditions. Then the fire. Bought another 78 Royale. But the Digi panel wasn't being made at that time. Both GMC stock temp gauges read the same. But it didn't take long before I had a feeling that this second Royale was running hotter. No boil overs. Just didn't feel right. So on our next trip. I raise the engine cover several times to check the engine temp sender with an inferred temp reader. Found that this Royale was generally operating about 10 degrees hotter with the stock gauge reading in the normal range as compared to our first GMC. Jim at Applied GMC had started producing the Digi panel. And had them at the GMCMI rally that we were going too. Installed the Digi panel at the rally. On the way home the panel also confirmed what I thought. So why the running hotter? Checked the thermostat. It was a good operating 180. But I changed to a proper 195. Fan clutch? Maybe. Well Jim K at Applied
> started selling a fan clutch that is controlled by engine block sensors. I liked the idea that this system is more proactive in controlling engine heat buildup. Plus I can turn the clutch on for the fan by a dash mounted switch when I want. So I bought that fan clutch at the GMCMI rally. I had recently put on an aluminum 307 Olds intake manifold. So I knew the engine was clean inside. Did the engine have a car water pump? Don't know. But even if there's a car pump. That's not the real big problem. Next I drained the radiator. Put my inspection camera in the radiator. Radiator's my problem. Looked heavily corroded at the crossover tubes. Going to put the radiator from the burned GMC in soon. Probably check/change water pump anyway while I'm doing other work in that area. Installing more gauges to look at isn't the best idea in my opinion. One. I want to be looking at the road for safe driving. Two. The Digi panel has gages. But it's audible alarm is your best engine/trans
> protection.
>
> Bob Dunahugh 78 Royale
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org

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Re: [GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem [message #327708 is a reply to message #327704] Wed, 03 January 2018 11:26 Go to previous messageGo to next message
Mike Kelley is currently offline  Mike Kelley   United States
Messages: 467
Registered: February 2017
Karma: -2
Senior Member
Hi Bob D.:
Would there be a source of distilled water there or should we each bring our own water also? I am sure we could buy 2 or 3 Gallons from the local Walmart or such!
I am really liking this idea for a tech session.
Mike/The Corvair a holic

Sent from my iPhone

> On Jan 3, 2018, at 10:43 AM, Bob Dunahugh wrote:
>
> Pete. That's a good idea. The owner could just bring new antifreeze. Flush, and then put the new antifreeze in. Have to find out what's the best way to dispose the old antifreeze there. We'd also have to have a pre event registration list to know what to be prepared for. Bob Dunahugh
>
>
>
> Mike K. Thanks. I think this is more of a problem then is generally thought. I pull higher GVW's more then most. And never had any add on items installed on our 403 GMC. Radiator inspections on attendees GMC's. Might make for a good tech session at the GMCMI rally in Tucson. Line them up, and start checking with my inspection camera. Drain pan, funnel, and the camera. At a cost of FREE. Good idea, or not. Any input out there? Bob Dunahugh
>
>
>
>
>
>
> Our first 78 Royale came with a Digi panel. I knew my engine temps under all conditions. Then the fire. Bought another 78 Royale. But the Digi panel wasn't being made at that time. Both GMC stock temp gauges read the same. But it didn't take long before I had a feeling that this second Royale was running hotter. No boil overs. Just didn't feel right. So on our next trip. I raise the engine cover several times to check the engine temp sender with an inferred temp reader. Found that this Royale was generally operating about 10 degrees hotter with the stock gauge reading in the normal range as compared to our first GMC. Jim at Applied GMC had started producing the Digi panel. And had them at the GMCMI rally that we were going too. Installed the Digi panel at the rally. On the way home the panel also confirmed what I thought. So why the running hotter? Checked the thermostat. It was a good operating 180. But I changed to a proper 195. Fan clutch? Maybe. Well Jim K at Applied started selling a fan clutch that is controlled by engine block sensors. I liked the idea that this system is more proactive in controlling engine heat buildup. Plus I can turn the clutch on for the fan by a dash mounted switch when I want. So I bought that fan clutch at the GMCMI rally. I had recently put on an aluminum 307 Olds intake manifold. So I knew the engine was clean inside. Did the engine have a car water pump? Don't know. But even if there's a car pump. That's not the real big problem. Next I drained the radiator. Put my inspection camera in the radiator. Radiator's my problem. Looked heavily corroded at the crossover tubes. Going to put the radiator from the burned GMC in soon. Probably check/change water pump anyway while I'm doing other work in that area. Installing more gauges to look at isn't the best idea in my opinion. One. I want to be looking at the road for safe driving. Two. The Digi panel has gages. But it's audible alarm is your best engine/trans protection.
>
> Bob Dunahugh 78 Royale
> _______________________________________________
> GMCnet mailing list
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Re: [GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem [message #327710 is a reply to message #327707] Wed, 03 January 2018 11:34 Go to previous messageGo to next message
Mike Kelley is currently offline  Mike Kelley   United States
Messages: 467
Registered: February 2017
Karma: -2
Senior Member
Emery S.:
More good GMC info and distinctly stated for us non mechanics - Well done and thanks!!!
I love this site and you guys who share good info (in a direct and easy to follow method).
Mike/The Corvair a holic
And a GMC 6 Wheeler in IL.

Sent from my iPhone

> On Jan 3, 2018, at 11:05 AM, Emery Stora wrote:
>
> The radiator cap should also be tested. Most only last about 2 years. The spring weakens as it opens and closes thousands of times on a trip. And the rubber seals deteriotate over time.
>
> I have a Stant pressure gauge that I use. It can also pressurize the radiator cold so it can be checked for leaks, bad hose connections, etc. I can bring that tester to the rally
>
> I once made a bet at a GMC Classics rally that at least half of the motorhome there would have bad radiator caps. Of the 24 tested 17 had bad caps!
>
> Emery Stora
>
>> On Jan 3, 2018, at 9:43 AM, Bob Dunahugh wrote:
>>
>> Pete. That's a good idea. The owner could just bring new antifreeze. Flush, and then put the new antifreeze in. Have to find out what's the best way to dispose the old antifreeze there. We'd also have to have a pre event registration list to know what to be prepared for. Bob Dunahugh
>>
>>
>>
>> Mike K. Thanks. I think this is more of a problem then is generally thought. I pull higher GVW's more then most. And never had any add on items installed on our 403 GMC. Radiator inspections on attendees GMC's. Might make for a good tech session at the GMCMI rally in Tucson. Line them up, and start checking with my inspection camera. Drain pan, funnel, and the camera. At a cost of FREE. Good idea, or not. Any input out there? Bob Dunahugh
>>
>>
>>
>>
>>
>>
>> Our first 78 Royale came with a Digi panel. I knew my engine temps under all conditions. Then the fire. Bought another 78 Royale. But the Digi panel wasn't being made at that time. Both GMC stock temp gauges read the same. But it didn't take long before I had a feeling that this second Royale was running hotter. No boil overs. Just didn't feel right. So on our next trip. I raise the engine cover several times to check the engine temp sender with an inferred temp reader. Found that this Royale was generally operating about 10 degrees hotter with the stock gauge reading in the normal range as compared to our first GMC. Jim at Applied GMC had started producing the Digi panel. And had them at the GMCMI rally that we were going too. Installed the Digi panel at the rally. On the way home the panel also confirmed what I thought. So why the running hotter? Checked the thermostat. It was a good operating 180. But I changed to a proper 195. Fan clutch? Maybe. Well Jim K at Applied
>> started selling a fan clutch that is controlled by engine block sensors. I liked the idea that this system is more proactive in controlling engine heat buildup. Plus I can turn the clutch on for the fan by a dash mounted switch when I want. So I bought that fan clutch at the GMCMI rally. I had recently put on an aluminum 307 Olds intake manifold. So I knew the engine was clean inside. Did the engine have a car water pump? Don't know. But even if there's a car pump. That's not the real big problem. Next I drained the radiator. Put my inspection camera in the radiator. Radiator's my problem. Looked heavily corroded at the crossover tubes. Going to put the radiator from the burned GMC in soon. Probably check/change water pump anyway while I'm doing other work in that area. Installing more gauges to look at isn't the best idea in my opinion. One. I want to be looking at the road for safe driving. Two. The Digi panel has gages. But it's audible alarm is your best engine/trans
>> protection.
>>
>> Bob Dunahugh 78 Royale
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
> _______________________________________________
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Re: [GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem [message #327712 is a reply to message #327704] Wed, 03 January 2018 13:44 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
G'day,

I hate to rain on your parade but I would suggest someone check with Kim Weeks before this party gets going as the KOA in Tucson
might not allow work like this to be done or having gallons anti-freeze dumped in their sewers, rain water drains, or on the ground.

Google "how to dispose of anti-freeze" and see what comes up.

Regards,
Rob M.
The Pedantic Mechanic
Sydney, Australia
AUS '75 Avion - The Blue Streak TZE365V100428
USA '75 Avion - Double Trouble TZE365V100426
USA '77 Kingsley - TZE 267V100808


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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: [GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem [message #327714 is a reply to message #327671] Wed, 03 January 2018 14:16 Go to previous messageGo to next message
jhbridges is currently offline  jhbridges   United States
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
Senior Member
I take old coolant to Advacnce since they're closest. All cooling system work around here is done outside the fence... we got dogs.

--johnny


Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons. Braselton, Ga. I forgive them all, save those who hurt the dogs. They must answer to me in hell
Re: [GMCnet] The stock temp gauge doesn't really tell you your operating temps. Why that's a problem [message #327720 is a reply to message #327712] Wed, 03 January 2018 18:39 Go to previous messageGo to next message
Emery Stora is currently offline  Emery Stora   United States
Messages: 959
Registered: January 2011
Karma: 4
Senior Member
Rob
Just about any auto parts store in the US will take used antifreeze just as they will take used motor oil and transmission fluid.
There are services that come around to auto parts stores and pump out their tanks of use material. Some even pay the store for it.

Bob has already checked that out.

Emery Stora
77 Kingsley
Frederick, CO

> On Jan 3, 2018, at 12:44 PM, Rob Mueller wrote:
>
> G'day,
>
> I hate to rain on your parade but I would suggest someone check with Kim Weeks before this party gets going as the KOA in Tucson
> might not allow work like this to be done or having gallons anti-freeze dumped in their sewers, rain water drains, or on the ground.
>
> Google "how to dispose of anti-freeze" and see what comes up.
>
> Regards,
> Rob M.
> The Pedantic Mechanic
> Sydney, Australia
> AUS '75 Avion - The Blue Streak TZE365V100428
> USA '75 Avion - Double Trouble TZE365V100426
> USA '77 Kingsley - TZE 267V100808
>
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org


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[GMCnet] Free Radiatior internal camera inspection, with radiator/cap pressure test. [message #327724 is a reply to message #327704] Wed, 03 January 2018 19:28 Go to previous messageGo to next message
BobDunahugh is currently offline  BobDunahugh   United States
Messages: 2465
Registered: October 2010
Location: Cedar Rapids, IA
Karma: 11
Senior Member
Subject line more appropriate.


Looking into doing this at the GMCMI Tucson Rally. If this works well. Maybe this could be added to future GMCMI rallies, and regional club rallies. I think this is a bigger problem then thought.

I had mentioned this to Kim this morning. We're not taking anything big apart. Drain fluids onto a pan. Do the camera inspection. Pressure test radiator, and cap. Put the antifreeze back in. There's just nothing to dispose of. If owners want to change their antifreeze at the same time. They can bring new antifreeze and distilled water. Then put that used antifreeze into those then empty containers. Thus nothing to dispose of at the rally site. I can find a place to recycle in the area as needed. Alex might be there to fix steering issue. There have also been weigh ins, headlight alignments, and many other tech sessions to make your GMC safer.
This internet site is a fantastic GMC info site. And I think that's it's major intention. Be very nice if GMCMI rallies with it's tech sessions, and regional club with their tech sessions be listed here at times. We're near the 6 Wheelers. If their rallies were mentioned here. Linda, and I would more then likely go. Any input? Bob Dunahugh



Pete. That's a good idea. The owner could just bring new antifreeze. Flush, and then put the new antifreeze in. Have to find out what's the best way to dispose the old antifreeze there. We'd also have to have a pre event registration list to know what to be prepared for. Bob Dunahugh



Mike K. Thanks. I think this is more of a problem then is generally thought. I pull higher GVW's more then most. And never had any add on items installed on our 403 GMC. Radiator inspections on attendees GMC's. Might make for a good tech session at the GMCMI rally in Tucson. Line them up, and start checking with my inspection camera. Drain pan, funnel, and the camera. At a cost of FREE. Good idea, or not. Any input out there? Bob Dunahugh






Our first 78 Royale came with a Digi panel. I knew my engine temps under all conditions. Then the fire. Bought another 78 Royale. But the Digi panel wasn't being made at that time. Both GMC stock temp gauges read the same. But it didn't take long before I had a feeling that this second Royale was running hotter. No boil overs. Just didn't feel right. So on our next trip. I raise the engine cover several times to check the engine temp sender with an inferred temp reader. Found that this Royale was generally operating about 10 degrees hotter with the stock gauge reading in the normal range as compared to our first GMC. Jim at Applied GMC had started producing the Digi panel. And had them at the GMCMI rally that we were going too. Installed the Digi panel at the rally. On the way home the panel also confirmed what I thought. So why the running hotter? Checked the thermostat. It was a good operating 180. But I changed to a proper 195. Fan clutch? Maybe. Well Jim K at Applied started selling a fan clutch that is controlled by engine block sensors. I liked the idea that this system is more proactive in controlling engine heat buildup. Plus I can turn the clutch on for the fan by a dash mounted switch when I want. So I bought that fan clutch at the GMCMI rally. I had recently put on an aluminum 307 Olds intake manifold. So I knew the engine was clean inside. Did the engine have a car water pump? Don't know. But even if there's a car pump. That's not the real big problem. Next I drained the radiator. Put my inspection camera in the radiator. Radiator's my problem. Looked heavily corroded at the crossover tubes. Going to put the radiator from the burned GMC in soon. Probably check/change water pump anyway while I'm doing other work in that area. Installing more gauges to look at isn't the best idea in my opinion. One. I want to be looking at the road for safe driving. Two. The Digi panel has gages. But it's audible alarm is your best engine/trans protection.

Bob Dunahugh 78 Royale
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Re: [GMCnet] Free Radiatior internal camera inspection, with radiator/cap pressure test. [message #327727 is a reply to message #327724] Wed, 03 January 2018 20:04 Go to previous messageGo to next message
Ken Henderson is currently offline  Ken Henderson   United States
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
Senior Member
Bob,

Now that you mention it, I don't recall enough attention being given here
to the various club events around the country. Why is it that we don't see
here links to the clubs' rally announcements, registration forms, and even
the event schedules? It would certainly be useful to many of us here, and
I'd think beneficial to the clubs. Has there ever been any prohibition of
such postings? I don't recall any.

Let's try it, even though it's too late to matter since the St.Augustine
rally of GMCSS & GMCDL starts next Thursday (we're going Tuesday):
http://gmcss.com/?page_id=517

Ken H.

On Wed, Jan 3, 2018 at 8:28 PM, Bob Dunahugh wrote:

> ​...
>
> This internet site is a fantastic GMC info site. And I think that's
> it's major intention. Be very nice if GMCMI rallies with it's tech
> sessions, and regional club with their tech sessions be listed here at
> times. We're near the 6 Wheelers. If their rallies were mentioned here.
> Linda, and I would more then likely go. Any input? Bob Dunahugh
>
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
Re: [GMCnet] Free Radiatior internal camera inspection, with radiator/cap pressure test. [message #327728 is a reply to message #327727] Wed, 03 January 2018 20:16 Go to previous messageGo to next message
James Hupy is currently offline  James Hupy   United States
Messages: 6806
Registered: May 2010
Karma: -62
Senior Member
GMC CASCADERS try to post dates of upcoming rallies months in advance on
our Web site. Gmcers.com. We plan on having a presence at the TUCSON event.
Many Cascaders are also members of other clubs, and it is no easy feat to
schedule rallies that do not conflict with other club events. On large
rallies, the venue's are usually booked years in advance. So, while we like
to accommodate members who still work, sometimes we just cannot work it
out. Does not mean that we can't do it when the schedule allows for it.
Jim Hupy, President, GMC CASCADERS.
Salem, Or

On Jan 3, 2018 6:06 PM, "Ken Henderson" wrote:

> Bob,
>
> Now that you mention it, I don't recall enough attention being given here
> to the various club events around the country. Why is it that we don't see
> here links to the clubs' rally announcements, registration forms, and even
> the event schedules? It would certainly be useful to many of us here, and
> I'd think beneficial to the clubs. Has there ever been any prohibition of
> such postings? I don't recall any.
>
> Let's try it, even though it's too late to matter since the St.Augustine
> rally of GMCSS & GMCDL starts next Thursday (we're going Tuesday):
> http://gmcss.com/?page_id=517
>
> Ken H.
>
> On Wed, Jan 3, 2018 at 8:28 PM, Bob Dunahugh wrote:
>
>> ​...
>>
>> This internet site is a fantastic GMC info site. And I think that's
>> it's major intention. Be very nice if GMCMI rallies with it's tech
>> sessions, and regional club with their tech sessions be listed here at
>> times. We're near the 6 Wheelers. If their rallies were mentioned here.
>> Linda, and I would more then likely go. Any input? Bob Dunahugh
>>
> _______________________________________________
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> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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Re: [GMCnet] Free Radiatior internal camera inspection, with radiator/cap pressure test. [message #327729 is a reply to message #327724] Wed, 03 January 2018 21:38 Go to previous messageGo to previous message
bdub is currently offline  bdub   United States
Messages: 1578
Registered: February 2004
Location: Central Texas
Karma: 5
Senior Member

This has been online for many years, Bob. Ya have to bookmark them for
yourself or use mine at http://bdub.net/GMCLinks.html

http://gmc.mybirdfeeder.net/

bdub
Everything in it's place ...


-----Original Message-----
From: Gmclist On Behalf Of Bob Dunahugh
Sent: Wednesday, January 3, 2018 7:28 PM

This internet site is a fantastic GMC info site. And I think that's it's
major intention. Be very nice if GMCMI rallies with it's tech sessions, and
regional club with their tech sessions be listed here at times. We're near
the 6 Wheelers. If their rallies were mentioned here. Linda, and I would
more then likely go. Any input? Bob Dunahugh




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bdub
'76 Palm Beach/Central Texas
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