2005 GMC Sierra overheating while driving

Dustin Roberts · May 10, 2021

I have 2005 GMC Sierra 1500 that has had an overheating problem for the last couple of months. The truck only gets hot when driving. As soon as I come to a stop it starts cooling back down (I don't have to shut the engine off to cool it back down). It sits right around 200 degrees when idling. After it overheated the first time I found a leak in the radiator and put a brand new radiator in but still had the same issue. Then I changed the coolant temp sensor and I found a few more leaks in a couple of hoses and changed all hoses with leaks but it still overheated. Next I changed the thermostat, water pump, serpentine belt and even the reservoir cap but still gets hot during a drive. Everything I've changed has seemed to move me in the right direction of not getting as hot as quick but still not solving the problem. As of right now there are no leaks and I can drive for about 20 min before the temp starts getting hot. Any advice is greatly appreciated. Thank you.

Sharpz · May 10, 2021

a few suggestions. 1st check your clutch fan. 2nd make sure you get all of the air out of the system or it will continue to overheat. Sometimes when redoing the whole system it can take some time. 3rd make sure the hoses are not collapsing

Dustin Roberts · May 11, 2021

15 hours ago, Sharpz said:

a few suggestions. 1st check your clutch fan. 2nd make sure you get all of the air out of the system or it will continue to overheat. Sometimes when redoing the whole system it can take some time. 3rd make sure the hoses are not collapsing

Thanks man! I changed the lower radiator hose thinking it might have been collapsing and it still overheated after that. Haven't changed the upper. I think that is the only hose that hasn't been changed at this point. Do you think there's any way that it could be collapsing? Today I'm planning on by passing the heater core all together to rule out it possibly being clogged. And if the problem is still there trying to burp the system again. Thanks for the help man!

Sharpz · May 11, 2021

its possible but not likely. If I had one guess it would be you have a pocket of air that is the culprit. When you go for your bleeding round next time, with cap off overfill container, and truck at idle as the truck warms up a bit squeeze the top hose a bit, with two hands like you are trying to force coolant through the water pump. you will see the reservoir push level push up. Make sure the truck is up to temp and no bubbles before putting the cap back on, dont be afraid to cycle this process multiple times to make sure the air is completely out.