I had a leak in antifreeze, overheating and overflow was full. I changed fan clutch and Water pump in November. Had a faulty fan clutch so exchanged it. Then leak again in March. Found a crack in radiaotr. Changed it and both hoses and 2 weeks later overheating again. Found fan clutch was out again. I changed it and drove 180 miles. Found antifreeze on ground under truck. Drove 10 miles and again, more antifreeze. Overflow is still full. Checked radiator and was a gallon low. What could it be?? Also have been having code p0014 lately but think thats another story. (Changed vvt solenoid, thinking timing chain with that one) Please - on the verge of shopping for new car due to stress and worry.
What it ended up being on my 05 trailblazer…after replacing the thermostat, water pump, flushing out the whole system…still had good hoses and clamps…it turned out to be the damned radiator cap! I’ve gone through 2 since I got it 5 years ago…it doesn’t have a pressure release anywhere on the coolant system except for at the cap so if it’s doing any boiling over for no reason…it’s probably that stupid cap..
when u refill the coolant, when it shows it’s topped off, do u run the engine with the cap still off till it’s warm and circulating to get all the air out of the system? Check out the videos on YouTube the channel is Chris fix…the one he does about head gasket leaks and how to diagnose if u have one…I chased the same issues in another vehicle for over a year and finally found the issue was a bad head gasket by the exhaust manifold…the air being allowed back into the coolant continually causes overheating but it will be randomly if it’s a small leak in the head gasket…
also, as much as I’m against adding anymore electric anything to these vehicles, in 5 years, I’ve changed outthe water pump 4x….it’s been the bearing that goes out so quickly..and the last one, the gasket turned to mush because of the dexcool antifreeze …the water pump was ok though…only thing that would cause the bearings to go out like this is from the fan being slightly off balance and putting stress on thetiny a$$ water pump it has…it’s almost comical….sounds like that might be something to help with the fan issue if u went electric fans instead…that huge fan attached to the Tiny water pump just doesn’t seem logical for lasting very long….