Possible overheating...but not.

[Bluwtr]

Hi all,

My 2005 Tahoe temp gauge jumped to almost 260. The system told me "Hot Coolant" then "Engine Overheat" or similar along those lines. Pulled over and found no coolant leaks, plenty in reservoir and the radiator fans weren't running. Father-in-law and I thought maybe a bad fan relay. Bought a new one, fans run. Mile or so down the road same problems.

We are thinking it's a false high temp warning so the computer is giving the data center messages even thought the engine temp is fine. This might would explain why the fans aren't running--engine isn't hot enough to need them.

Is the dash gauge and computer fed from the same sensor that the fans run from?

Suggestions greatly appreciated.

Wes

 

[Bluwtr]

Update....changed temp sensor, had a gasket leak on water pump and changed them. Using i.r. sensor, temps are as expected and engine is running high. Engine temp is around 220 or so.

Really need some help here.

 

[Bluwtr]

Maybe this will help someone else. Long story short, thought the radiator was plugged. Flushed it many times and the system was cleaning, but not the answer. Next thought was blown head gasket--a little white smoke and some water from tail pipe. Added Blue Devil--still over heating. Noticed fans were not blowing "hot" air from the radiator. Radiator had a large air bubble in it--almost one gallon of water. Filled system--problem solved.