| Engine cooling. Can't get it right [message #253747] |
Sun, 29 June 2014 23:57  |
BRDRVR
Messages: 184
Registered: July 2013
Location: Clearwater, FL-Gerlach,NV
Karma: 8
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I picked up a unit 2 weeks ago. Got on the roads d the lower hose went. Replaced. 10 miles later upper hose blew. Replaced it. Filled it up and took off. 5 miles later it started to get hot. Replaced water pump. Let it idle for a while seemed good. Took off again and it started to get hot. Checked it out and had 3 small holes in radiator. At that point I trailered. Had radiator rebuilt and took off to Georgia with it and about 70 miles it got hot and popped the new ràdiator. Went back to shop and pulled a known good radiator out of one of my units and swapped it out. Got 150 miles and she's running hot again. Brand new pump, rad, hoses. It never had a thermostat. The lines running back to heater are no longer there and there is a hose from the bypass to the back of the manifold. No heater hoses either. All I can think of is I got a bad pump but it will run cool for a while them just hear up. Ideas anyone? As I sit here getting feasted upon by super Mosquitos. Help
Thanx. David
David Gourdine
http//www.blackrockdesertrvrental.com
booking@blackrockdesertrvrental.com
727-657-1955
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| Re: Engine cooling. Can't get it right [message #253755 is a reply to message #253747] |
Mon, 30 June 2014 00:32  |
glenn2726
Messages: 234
Registered: June 2014
Location: Topeka, Kansas
Karma: 2
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Fan clutch and belts? Losing any coolant...like a leaking head gasket? Good luck, Glenn
Glenn W
Topeka, KS
1974 GMC 26 ft. Color:Camel Interior:Canyon Land
Side Bath, Rear Sitting Area
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| Re: Engine cooling. Can't get it right [message #253757 is a reply to message #253747] |
Mon, 30 June 2014 00:38 |
mrgmc3
Messages: 210
Registered: September 2013
Location: W Washington
Karma: 2
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Think of your cooling system like a bathtub. The engine pours heat in, and the cooling system drains it off. You have replaced most parts of the cooling system. Make sure you have a thermostat that works or an orifice of similar size to the stat. Water pumps are a crap shoot, some have stamped impellers of insufficient flow. Cast impellers usually flow better. What about the passages in block and head? There could be a lot of crud if it has been sitting awhile. Also you made no mention of fan or fan clutch. You might be able to get by without any fan above 45 mph as airflow is sufficient. If your fan clutch is stuck "on" it may actually impede airflow at higher road speeds.
Ok so we have discussed the heat "outflow" of the bathtub..
Also consider the heat generated by the engine. If you are running too lean or spark advance is way off you may be rejecting more heat to the coolant. Even a "perfect" cooling system might not be able to keep up under these circumstances.
These Olds engines are great passenger car engines, but we are taxing them with the equivalent of pulling a 5000 lb trailer all the time (relative to a Toronado), so everything has to be in good order for the system to balance.
Chris Geils - Twin Cities / W Wa
1978 26' Kingsley w/ very few mods; PD9040, aux trans cooler, one repaint in stock colors, R134a, Al rad, Alcoas, 54k mi
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| Re: Engine cooling. Can't get it right [message #253758 is a reply to message #253755] |
Mon, 30 June 2014 00:40 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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glenn2726 wrote on Sun, 29 June 2014 22:32Fan clutch and belts? Losing any coolant...like a leaking head gasket? Good luck, Glenn
Popping hoses sure sounds like a cracked head or failed head gasket to me. Is the water blowing out of the over flow tank too? A radiator shop should be able to tell you if there is combustion leakage into the coolant. Not a fun problem to have on the road.
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: Engine cooling. Can't get it right [message #253760 is a reply to message #253747] |
Mon, 30 June 2014 00:42 |
BRDRVR
Messages: 184
Registered: July 2013
Location: Clearwater, FL-Gerlach,NV
Karma: 8
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Just pulled top hose and cranked it up. Pump is not pumping. I remember now hearing never replace pump without replacing fan clutch. That makes sense. No air being pulled doesn't matter what is new. F@CK. Nothing I can do now cept wait till sunup. Thanx for the enlightenment
Thanx. David
David Gourdine
http//www.blackrockdesertrvrental.com
booking@blackrockdesertrvrental.com
727-657-1955
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| Re: Engine cooling. Can't get it right [message #253762 is a reply to message #253747] |
Mon, 30 June 2014 00:50 |
glenn2726
Messages: 234
Registered: June 2014
Location: Topeka, Kansas
Karma: 2
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Hey David, at least you have something to overnight in..so not totally bad. The fan clutch could have been what was causing the problem to begin with. It would be a good time to replace your belts while you have the fan off, could save you from having to do that at an inopportune moment. Hopefully you'll be back on the road tomorrow and everything will be behind you...Safe travels, Glenn
Glenn W
Topeka, KS
1974 GMC 26 ft. Color:Camel Interior:Canyon Land
Side Bath, Rear Sitting Area
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| Re: Engine cooling. Can't get it right [message #253763 is a reply to message #253747] |
Mon, 30 June 2014 00:50 |
BRDRVR
Messages: 184
Registered: July 2013
Location: Clearwater, FL-Gerlach,NV
Karma: 8
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Don't think I have a bad head gasket. Pulled compression across the board between 140-150no evidence of seepage. Oil looks good no steam or funny odors at the tail pipe. Hard to say with blockage. I was running 100% coolant and the color look good as it gushed.
David Gourdine
http//www.blackrockdesertrvrental.com
booking@blackrockdesertrvrental.com
727-657-1955
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| Re: Engine cooling. Can't get it right [message #253764 is a reply to message #253760] |
Mon, 30 June 2014 00:51 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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Senior Member |
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BRDRVR wrote on Sun, 29 June 2014 22:42Just pulled top hose and cranked it up. Pump is not pumping. I remember now hearing never replace pump without replacing fan clutch. That makes sense. No air being pulled doesn't matter what is new. F@CK. Nothing I can do now cept wait till sunup. Thanx for the enlightenment
Thanx. David
Don't see the connection of the pump not pumping and the fan? If the new pump is moving 0 water it must have a loose impeller or something is plugged up ??
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: Engine cooling. Can't get it right [message #253766 is a reply to message #253764] |
Mon, 30 June 2014 00:59 |
jim kanomata
Messages: 257
Registered: March 2007
Location: fremont,ca
Karma: 12
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I agree that possibly there might be a head gaskett problem, however if you were able to go 100 miles, maybe not.
Be sure to run the specified cap of 7-10 psi cap.
After all this overheating, you will have head gasket problem.
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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| Re: Engine cooling. Can't get it right [message #253767 is a reply to message #253747] |
Mon, 30 June 2014 00:59 |
BRDRVR
Messages: 184
Registered: July 2013
Location: Clearwater, FL-Gerlach,NV
Karma: 8
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I guess I'm assuming that a faulty fan clutch would ruin the pump?
David Gourdine
http//www.blackrockdesertrvrental.com
booking@blackrockdesertrvrental.com
727-657-1955
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| Re: Engine cooling. Can't get it right [message #253768 is a reply to message #253747] |
Mon, 30 June 2014 00:59 |
glenn2726
Messages: 234
Registered: June 2014
Location: Topeka, Kansas
Karma: 2
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Senior Member |
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Water pump could have been bad from get go..Hard to look in the radiator opening to see if coolant is moving on these rigs..if fan clutch was bad then yes not getting much cooling through radiator, that could be why you could drive a ways before it overheated. Were you running the dash air conditioning also? Seeing and smelling coolant is never a good thing...lol...Hope tomorrow is a great day for your travels...Glenn
Glenn W
Topeka, KS
1974 GMC 26 ft. Color:Camel Interior:Canyon Land
Side Bath, Rear Sitting Area
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| Re: Engine cooling. Can't get it right [message #253769 is a reply to message #253766] |
Mon, 30 June 2014 01:07 |
jim kanomata
Messages: 257
Registered: March 2007
Location: fremont,ca
Karma: 12
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Senior Member |
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I experienced a bad pump where the impeller was spinning on the shaft and not pumping enough.
We checked everything and even discussed the problem with Dick Paterson.
Dick told me that he had that same problem on couple occasion.
Never amaze me as to what can be wrong with new parts.
This month we returned more new parts to the warehouse than ever before.
Jim Kanomata
Applied/GMC, Fremont,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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| Re: Engine cooling. Can't get it right [message #253771 is a reply to message #253747] |
Mon, 30 June 2014 01:10 |
BRDRVR
Messages: 184
Registered: July 2013
Location: Clearwater, FL-Gerlach,NV
Karma: 8
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Senior Member |
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Hard to say if pump was shite. It came from auto zone. Is there a way to test or determine bad fan clutch?
David Gourdine
http//www.blackrockdesertrvrental.com
booking@blackrockdesertrvrental.com
727-657-1955
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| Re: Engine cooling. Can't get it right [message #253773 is a reply to message #253747] |
Mon, 30 June 2014 01:23 |
glenn2726
Messages: 234
Registered: June 2014
Location: Topeka, Kansas
Karma: 2
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Senior Member |
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Hey Len, I think our units use a thermostatically controlled fan clutch, which means they spin up once the engine reaches operating temperature. So you will most likely need to see if it is working with the engine running and at temperature. If it was me i would just go ahead and replace it and the belts since you are replacing the water pump..good time to take preventative measures...Glenn
Glenn W
Topeka, KS
1974 GMC 26 ft. Color:Camel Interior:Canyon Land
Side Bath, Rear Sitting Area
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| Re: Engine cooling. Can't get it right [message #253775 is a reply to message #253773] |
Mon, 30 June 2014 01:59 |
Bullitthead
Messages: 1411
Registered: November 2013
Karma: 5
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100% coolant does not transfer heat nearly as well as having 50% with water. Straight water gives the best heat absorption but gives no corrosion protection. 70% coolant is the max concentration recommended by the coolant manufacturers in COLD climates, so you might want to add water to top off. Start with a cold engine and see how quick pressure builds up in the system. If you have pressure before heat then there is a head gasket problem. If the rig overheats at highway speed the fan clutch is not the root problem unless it is frozen. Watch the fan when you shut off a hot engine, it should not continue to spin freely. Is the radiator airflow clear? Should be a big breeze coming through there. Hot air from the radiator should give a stiff fan clutch immediately after shutdown.
Terry Kelpien
ASE Master Technician
73 Glacier 260
Smithfield, Va.
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| Re: Engine cooling. Can't get it right [message #253776 is a reply to message #253747] |
Mon, 30 June 2014 03:56 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Go to NAPA and get part number 43-100 or 130-1260 (older number). Before you leave the parts counter measure the diameter of the impeller. It should 4.0" to 4.25". If it is smaller do not bother with it. The OEM pump used a 4.25" diameter impeller.
I have a note that AZ also has a high volume pump but I have never seen or used one so the note may be wrong. You can ask to see part number 55-21118. Again measure the impeller for 4" or more.
It turns out these pumps all used the same casting. They just varied the impeller size, style, and heater hose ports depending on the need for the the individual engine and cooling system.
What was wrong with the original pump?
Do you still have it?
There is not much to go wrong with a water pump. Seals, bearings, plus in rare cases the impeller loosening up on the shaft is all that can go bad. If you have the original pump and it is 4" and the seals and bearing are good, you might reinstall it.
Change the coolant to 50/50. You will get better heat transfer.
Finally on that rebuilt radiator, how many fins per inch did they use? I read somewhere that they need to have 14 or 16 per inch and if they used 10 per inch it will not cool well enough for a GMC.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: Engine cooling. Can't get it right [message #253781 is a reply to message #253771] |
Mon, 30 June 2014 05:26 |
roy1
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
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Senior Member |
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BRDRVR wrote on Sun, 29 June 2014 23:10Hard to say if pump was shite. It came from auto zone. Is there a way to test or determine bad fan clutch?
If there isn't any coolant coming out of the top hose I would be pulling the pump for sure new or otherwise. A bad fan clutch wouldn't cause this kind of problem. If the bearing in the clutch were bad and caused the shaft too wobble it would take out the pumps bearings and seal over time. If the pump is moving water normally you should hear the clutch fan kick in while driving when the coolant gets too around 220 degrees and quiet down around 190. If you don't hear this I would get a new fan clutch as this would mean you don't have a heavy duty clutch or yours isn't" working. Auto zone has a heavy duty clutch for about $65 . The last four numbers in the part are 2797 I can't remember the first two numbers. In your case I would just replace the pump and clutch at the same time. Don't forget to be sure you get the correct pump gasket as there are 2 different ones.
Roy Keen
Minden,NV
76 X Glenbrook
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| Re: Engine cooling. Can't get it right [message #253790 is a reply to message #253776] |
Mon, 30 June 2014 07:11 |
Jim Galbavy
Messages: 1443
Registered: August 2007
Karma: 7
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I was thinking along the some lines as Ken & JimK. I would think the water pump.
When I first got my GMC I ran for 4 years with a fan clutch that wasn't working
because I did know any better. Water temp ran 195-205 F most of the time except
when I would pull long grades in the summer. When I found out about fan clutches I was
at Sirums and he installed one for me. Scared the pea out of me when I first heard it spin
up, but watched the temp drop 5-7 F. so knew all was better if not well. When I first got my
coach I used a coolant flush kit. System was originally a mess. In my case it appeared to be the
rad. Good luck, hope you are back on the road by now.
jim galbavy
'73 x-CL ANNIE
Lake Mary, FL
P.S.: Should have added that I did have an electric fan that pulled air thru the rad. when the dash A/C
was on.
[Updated on: Mon, 30 June 2014 07:14] Report message to a moderator |
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| Re: Engine cooling. Can't get it right [message #253800 is a reply to message #253790] |
Mon, 30 June 2014 08:36 |
Chr$
Messages: 2690
Registered: January 2004
Location: Scottsdale, AZ
Karma: 1
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David, Excessive crud in the rad can cause similar problems. My 66 Nova had the bottom half of the radiator blocked due to sitting too long. Ran fine for a while, then started to over heat. The crud can prevent flow through the water pump so you would think the pump is bad when it is not getting any coolant.
My GMC took about an hour of flushing - filling - flushing to get all the brown crap out too.
also +1 on 50-50. Never use 100% coolant. You are better off using 100% water in a pinch, but you really should use 50-50.
-Chr$: Perpetual SmartAss
Scottsdale, AZ
77 Ex-Kingsley 455 SOLD!
2010 Nomad 24 Ft TT 390W PV W/MPPT, EV4010 and custom cargo door.
Photosite: Chrisc GMC:"It has Begun" TT: "The Other Woman"
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