QuestionJust bought a used LHS, ran good on a 3 hour drive trip, but start to run hot around town traffic. Add coolant fuel and some leakage of the coolant - and still running hot. droped off at shop to run a cooling diagnonisic check, do you have suggestions:) thank you
AnswerHi Betty,
There are quite a few reasons for the engine to run hot:
air trapped in the cooling system, loss of coolant due to leakage in radiator, hoses, or engine head gasket, fan(s) not coming on when called for by temperature sensor, temperature sensor off-calibration, partially clogged radiator, water pump impeller defective, air flow thru radiator fins blocked by debris. To differentially diagnose which of these may explain the problem relies upon other tests/observations. So if you can tell me anything else about the cooling system/engine operation that would be helpful. Is there any sign of a coolant leak? Do you see unusual amounts of white smoke coming from the tailpipe when you first start the car from a cold engine condition, do you hear are gurgling/bubbling sounds from the engine, do both side edges of the radiator (the manifolds) feel equally hot, how high is the gauge reading, do the fans come on when you turn on the AC or the defrost position of the heater control panel? These are all relevant to such a diagnosis. When you get the diagnostic check from the shop, ask them what they think is wrong, what they intend to do, and how much it will cost? Then write back and let me know and we can compare notes.
Roland
