No Engine Heat

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Crippin87

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Ok so recently I replaced my radiator. My factory one got a split in the plastic tank so I replaced with an all aluminum one. After dropping the new one in I noticed I had a very low temp on the gauge. I assumed it was the thermostat so I replaced it. After doing so, I noticed a leak on the water pump of course lol so I replaced that too. So after all of that work I still can not get the motor to warm up. At idle the temp gauge will rise to about a quarter of the gauge, while driving it barely moves off the bottom line. I attached a pic of where it sits while in motion. I thought it was just air stuck in the system so I have tried to “burp” it probably 4 times with no success. Today I took the heater core hoses and pushed compressed air through it thinking it might flush out a blockage or something, then pushed the air out with the water hose before reconnecting the heater core hoses. There was no blockage and that also did not work. I’m looking for any help or advice anyone on here can provide because I am all out of ideas lol.

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Fless

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@Crippin87 the factory radiators have a restriction for the hose going to the surge tank. Aftermarket radiators often don't have this restriction, and the coolant flows too freely into the surge tank, causing low engine temps. If yours doesn't have the restriction in the radiator, you'll need to do something to make that hose a bit less free flowing.

I know there's a thread or two on here about it and if I find it I'll edit it into this message.

EDIT: here's one of a few: https://www.tahoeyukonforum.com/thr...ing-low-operating-coolant-temperature.111471/
 
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OR VietVet

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An all aluminum radiator dissipates heat real quick but that is after the hot coolant gets to it. Since it seems you had good heat before radiator replacement I would check to see how that can effect that system. I think I read here somewhere about all aluminum radiators and bypass lines and.....hell I just don't remember. Did you put the correct temp thermostat in it? Pushing compressed air thru a heater core is risky about blowing a seam in it. A water hose would have been as far as I would have went. Someone will help here.
 
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Crippin87

Crippin87

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@Crippin87 the factory radiators have a restriction for the hose going to the surge tank. Aftermarket radiators often don't have this restriction, and the coolant flows too freely into the surge tank, causing low engine temps. If yours doesn't have the restriction in the radiator, you'll need to do something to make that hose a bit less free flowing.

I know there's a thread or two on here about it and if I find it I'll edit it into this message.

EDIT: here's one of a few: https://www.tahoeyukonforum.com/thr...ing-low-operating-coolant-temperature.111471/
Wow! That is identical to my issue lol. I have searched high and low trying to find an answer and there it is lol...hopefully. So simple.
 

Doubeleive

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ya if it's not the flow going back into the reservoir then next suspect would be a thermostat stuck open, you should be able to just look at the reservoir tank and see if the coolant is just flowing thru.
 
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Crippin87

Crippin87

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ya if it's not the flow going back into the reservoir then next suspect would be a thermostat stuck open, you should be able to just look at the reservoir tank and see if the coolant is just flowing thru.
It does, and just like the other thread states it has a ton of flow immediately. I’m going to look into some some way pinching the flow down. It would be nice if there was a hose the correct size on either end but smaller in the middle. It would have been a lot cooler if GM just put a smaller diameter hose on there instead of a restrictor in the radiator lol. Reading through that thread at least makes me feel better, I’m not the only person that this issue has stumped lol.
 

Doubeleive

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It does, and just like the other thread states it has a ton of flow immediately. I’m going to look into some some way pinching the flow down. It would be nice if there was a hose the correct size on either end but smaller in the middle. It would have been a lot cooler if GM just put a smaller diameter hose on there instead of a restrictor in the radiator lol. Reading through that thread at least makes me feel better, I’m not the only person that this issue has stumped lol.
others have just put a hose clamp on it and tightened it down, it's something the radiator manufacturer overlooked, usually crops up on the cheaper models.
 

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