Heater flow/temp issue?

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454cid

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Gates water pumps seem to just be cheap imports. I had one that looked pretty good but the bearing/seal went out after a year or two. I got a warranty replacement and it was a different casting. I still have the replacement sitting in its box as I had already purchased another brand of cheap import .one of these days I'll get my old GM pump rebuilt.
 

1990Z71Swede

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Changed thermostat today, Turns out what was in there was a 205 degree Motorad :)

There where also some evidence of a previous expert's high class work...

Both RTV and a Gasket, love it...
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Hold on....:)
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Anyhow with an new 195 degree thermostat installed the right way, the temperature gauge is somewhat more stable and if the unmarked line beween 20 and 100 is 80 degrees centigrade I would call it acceptable. Also The gauge appears to spend more time near the 100 mark than before. I suspect the radiator fan might be running more than it really should. Or it is just normal behaviour for a Z71 with the HD radiator.

But Cabin Heat is still lacking, this is what the heater return flow looks like at idle. Is this normal? Shouldn't there be way more? It looks a bit weak but IDK...
Oh yeah The heater inlet hose is slightly warmer than before. I would say the same as the upper radiator hose, so the engine runs a little bit hotter or maybe rather at a more stable temp than before. Return hose still cold...ish though :oops:.

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Jonathanhicks

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I always use the gasket and rtv because they tend to leak if I don't. Back to the leak of heat sounds like a air pocket. Try running it with the radiator cap off for 10 to 15 minutes that should get the air out
 

Schurkey

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Both RTV and a Gasket, love it...
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Frickin' marvelous.


Cabin Heat is still lacking, this is what the heater return flow looks like at idle. Is this normal? Shouldn't there be way more? It looks a bit weak but IDK...
Flow into the heater core is deliberately restricted. The opening in the quick-coupler is about a quarter-inch diameter, but the area is even less than that due to the plastic divider down the middle of the opening.

Oh yeah The heater inlet hose is slightly warmer than before. I would say the same as the upper radiator hose, so the engine runs a little bit hotter or maybe rather at a more stable temp than before. Return hose still cold...ish .
If the inlet hose is hot, and the outlet hose is cold, the heater core is partially-plugged, or your ambient temp is enormously cold.

I always use the gasket and rtv because they tend to leak if I don't.
RTV Silicone is not a suitable gasket dressing. There's a dozen+ products that are excellent gasket dressings, and any one of them is way better than RTV Silicone.

For the record, Fel-Pro says their gaskets don't need sealers. But adding a sealer to a gasket is a hard habit to break.

Back to the leak of heat sounds like a air pocket. Try running it with the radiator cap off for 10 to 15 minutes that should get the air out
Given that the radiator cap is the high-point of the cooling system, it's really unlikely to be "air locked" or an "air pocket".
 

1990Z71Swede

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Yes I was aware of the Restriction in the water outlet and also why it is there. I have been educating myself a a lot recently, mainly on this forum :) :waytogo:

I have also been reluctant to touch it. Apparently they tend to brake off if you just look at them.

Would you say that flow in the picture is about normal, or clearly a sign of a clogged heater core. Engine at operating temp and idling.
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This is what the temp gauge looks like.

This is as low as it goes when the thermostat is open.
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This is as high as it goes just before the thermostat opens. Disregard the oil pressure gauge...:)
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GoToGuy

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I've never used a gates water pump. A Lot of gates V belts, serpentine belts, and hoses. And they were the asked for belts in the parts store I worked at, for the industrial and agricultural use. Green stripe, and two or three matched set for belt driven accessories.
 

1990Z71Swede

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Or your back to the missing (detiereriated) weatherstrip inside the heater box.
This is a possibility fer sure, but I'm putting this one on the backburner for now. It does get colder sometimes when driving, but the return hose is never hot, not even when sitting idling at operating temp. The air out of the vents does get warm after a while though, but the return hose... still cold. Did the same test on the 2008 Suburban and the return hose was pretty warm to the touch. The pickup does blow air out of all the vents at the same time though, one mode door linkage is missing its spring and plastic pieces, and I think the actuator is dead too. Blend door works, Resirc actuator.... Status unknown... This truck is keeping me busy :)

Edit: Mode door actuator works, linkage looks like this. Is it possible to by spares, or do I need to fab up my own "spares" :) ? (The fluid hanging of the linkage is CRC penetrating oil)
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