| water pump or belt symptom? [message #267323] |
Mon, 08 December 2014 07:42  |
Tilerpep
Messages: 404
Registered: June 2013
Location: Raleigh, NC
Karma: 7
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Senior Member |
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Good morning,
Took the coach out a few weeks ago and it didn't develop heat through the dash, and I noticed my gauge wasn't reading consistent like normal. As it is cold I would like to narrow down my search when I go under later this week...
I have had some belt issues (loosening) but I wouldn't think all three are slipping to not spin the water pump. I would assume a heater box problem, but the guage makes me think more to engine. Stuck open thermostat a possibility? (replaced 1.5 years ago). Should I be thinking pump? I did not notice any wobble when I put the new fan clutch on earlier this summer.
I found this thread with good tips on water pump itself
http://gmc.mybirdfeeder.net/GMCforum/index.php?t=msg&goto=258922&rid=3615&srch=water+pump#msg_258922
but hoping for broader input.
Thanks,
Tyler
1975 Glenbrook, 1978 Royale rear bath
Raleigh, NC
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| Re: water pump or belt symptom? [message #267324 is a reply to message #267323] |
Mon, 08 December 2014 08:32  |
lqqkatjon
Messages: 2324
Registered: October 2010
Location: St. Cloud, MN
Karma: 5
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Senior Member |
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IR thermometer will help you hunt down the problem pretty quickly.
http://www.amazon.com/Nubee%C2%AE-Temperature-Non-contact-Infrared-Thermometer/dp/B00CVHIJDK/ref=sr_1_1?ie=UTF8&qid=1418048869&sr=8-1&keyw ords=IR+thermometer
That will tell you for sure if problem is engine, or heat box related, in short order.
someone else might be able to chime in, as to what temps you might expect to see and where you should look. I usually will check upper and lower hoses temps, and hose going into heater core temp. But without running mine, I can't tell you the range of temps you should see.
Jon Roche
75 palm beach
EBL EFI, manny headers, Micro Level, rebuilt most of coach now.
St. Cloud, MN
http://lqqkatjon.blogspot.com/
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| Re: water pump or belt symptom? [message #267326 is a reply to message #267323] |
Mon, 08 December 2014 09:44 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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Senior Member |
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Sir, first I would check coolant level in radiator. If low it would act as you described. Coolant clamps will be looser in cold weather and sometimes leak. The water pump weep hole is hard to see but if low on water you gotta get a good light and crawl under it and check for any coolant trails? If it is full start and let it warm up and feel the heater hose under the front hatch and see if hoses is warm on both sides of the vacuum valve. Get someone to move lever from vent to heat and see if valve is working.
Tilerpep wrote on Mon, 08 December 2014 08:42Good morning,
Took the coach out a few weeks ago and it didn't develop heat through the dash, and I noticed my gauge wasn't reading consistent like normal. As it is cold I would like to narrow down my search when I go under later this week...
I have had some belt issues (loosening) but I wouldn't think all three are slipping to not spin the water pump. I would assume a heater box problem, but the guage makes me think more to engine. Stuck open thermostat a possibility? (replaced 1.5 years ago). Should I be thinking pump? I did not notice any wobble when I put the new fan clutch on earlier this summer.
I found this thread with good tips on water pump itself
http://gmc.mybirdfeeder.net/GMCforum/index.php?t=msg&goto=258922&rid=3615&srch=water+pump#msg_258922
but hoping for broader input.
Thanks,
Tyler
C. Boyd
76 Crestmont
East Tennessee
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| Re: water pump or belt symptom? [message #267327 is a reply to message #267323] |
Mon, 08 December 2014 10:48 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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Senior Member |
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Tilerpep wrote on Mon, 08 December 2014 06:42Good morning,
Took the coach out a few weeks ago and it didn't develop heat through the dash, and I noticed my gauge wasn't reading consistent like normal. As it is cold I would like to narrow down my search when I go under later this week...
I have had some belt issues (loosening) but I wouldn't think all three are slipping to not spin the water pump. I would assume a heater box problem, but the guage makes me think more to engine. Stuck open thermostat a possibility? (replaced 1.5 years ago). Should I be thinking pump? I did not notice any wobble when I put the new fan clutch on earlier this summer.
I found this thread with good tips on water pump itself
http://gmc.mybirdfeeder.net/GMCforum/index.php?t=msg&goto=258922&rid=3615&srch=water+pump#msg_258922
but hoping for broader input.
Thanks,
Tyler
I would suspect a thermostat, vacuum shut off valve, and non-moving temperature door in that order.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: water pump or belt symptom? [message #267351 is a reply to message #267323] |
Tue, 09 December 2014 07:48 |
kerry pinkerton
Messages: 2565
Registered: July 2012
Location: Harvest, Al
Karma: 15
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Senior Member |
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I'm with Chuck Boyd. I'd check coolant level. When coolant level drops, the thermometer is no longer in coolant and will read cold. Insufficient (or none) hot coolant gets to the heater core so it blows cold air. In fact, the engine block is overheating and you can blow head gaskets, crack heads, and do other damage.
On our first trip with the coach we got so cold that we started the generator and plugged in heaters. The wife had on about 6 layers of clothes and was wrapped in a blanket. We didn't realize what was going on and apparently it had started with the PO.
Shortly after we got home, I sent the oil sample I'd pulled when we first got the coach. It came back with coolant in the oil which breaks down the oil. I immediately pulled another sample and it came back worse with even more coolant percentage. Tightened the heads and watched things. Coolant was still going away slowly. The next sample showed coolant and COPPER in the oil. Teardown showed abnormal wear in bearings due to the breakdown in lubricity of the oil by the antifreeze. It also showed the head gasket was allowing coolant into the cylinder.
The moral of this story is to check the coolant...often. It was an expensive lesson.
Kerry Pinkerton - North Alabama
Had 5 over the years. Currently have a '06 Fleetwood Discovery 39L
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| Re: water pump or belt symptom? [message #267352 is a reply to message #267323] |
Tue, 09 December 2014 07:57 |
kerry pinkerton
Messages: 2565
Registered: July 2012
Location: Harvest, Al
Karma: 15
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Senior Member |
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Tilerpep wrote on Mon, 08 December 2014 07:42...and I noticed my gauge wasn't reading consistent like normal. ...
Tyler to add to my previous post, there are only three things that I can think of that will cause an inconsistent gauge reading.
1- Bad thermostat allowing temperature to fluctuate. An IR thermostat is your friend. Temp readings on the upper hose gooseneck (just above the thermostat) should be pretty consistent.
2- Bad gauge (doubtful)
3- Low coolant allowing the gauge sending unit to not be in the coolant all the time.
Kerry Pinkerton - North Alabama
Had 5 over the years. Currently have a '06 Fleetwood Discovery 39L
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| Re: water pump or belt symptom? [message #267366 is a reply to message #267352] |
Tue, 09 December 2014 15:54 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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kerry pinkerton wrote on Tue, 09 December 2014 07:57Tilerpep wrote on Mon, 08 December 2014 07:42...and I noticed my gauge wasn't reading consistent like normal. ...
Tyler to add to my previous post, there are only three things that I can think of that will cause an inconsistent gauge reading.
1- Bad thermostat allowing temperature to fluctuate. An IR thermostat is your friend. Temp readings on the upper hose gooseneck (just above the thermostat) should be pretty consistent.
2- Bad gauge (doubtful)
3- Low coolant allowing the gauge sending unit to not be in the coolant all the time.
4. Do not forget that the problem could also be electrical.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: water pump or belt symptom? [message #269175 is a reply to message #267323] |
Wed, 07 January 2015 22:03 |
Tilerpep
Messages: 404
Registered: June 2013
Location: Raleigh, NC
Karma: 7
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Senior Member |
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Follow up post for others down the line in the same boat...
Turned out to be a Failsafe thermostat had caught open. Either had a spike when I was having trouble sorting out the fan clutch, or the thermostat just failed. It held pretty steady temp when weather was hot, but with cold weather became an issue. I dropped it this time from 195 to 180 degree and happily saw a rock steady gauge reading just a tick below previous mark (I had previously switched to the NAPA temp sender mentioned in other threads that read on center mark with 195, about a mm below with 180)
Took a few hot/cold cycles to refill coolant up through the heater box, and inside heat back in business. (Temp slider sure is stiff...suggestions of what miracle goo to spray in there and not mess things up worse?) Too bad I didn't get it straightened out in time to do a tacky light tour last month!
1975 Glenbrook, 1978 Royale rear bath
Raleigh, NC
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| Re: [GMCnet] water pump or belt symptom? [message #269194 is a reply to message #269175] |
Thu, 08 January 2015 06:30 |
Mr ERFisher
Messages: 7117
Registered: August 2005
Karma: 2
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Senior Member |
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On Wednesday, January 7, 2015, Tyler wrote:
> Follow up post for others down the line in the same boat...
> Turned out to be a Failsafe thermostat had caught open.
You were very lucky. They often stick closed. Is why I use restrictions
Erf
> Either had a spike when I was having trouble sorting out the fan clutch,
> or the thermostat
> just failed. It held pretty steady temp when weather was hot, but with
> cold weather became an issue. I dropped it this time from 195 to 180 degree
> and
> happily saw a rock steady gauge reading just a tick below previous mark (I
> had previously switched to the NAPA temp sender mentioned in other threads
> that read on center mark with 195, about a mm below with 180)
>
> Took a few hot/cold cycles to refill coolant up through the heater box,
> and inside heat back in business. (Temp slider sure is stiff...suggestions
> of
> what miracle goo to spray in there and not mess things up worse?) Too bad
> I didn't get it straightened out in time to do a tacky light tour last
> month!
> --
> 1975 Glenbrook
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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>
--
Gene Fisher -- 74-23,77PB/ore/ca
“Give a man a fish; you have fed him for today --- give him a URL and
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http://gmcmotorhome.info/
Alternator Protection Cable
http://gmcmotorhome.info/APC.html
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