QuestionQUESTION: This is so simple; the engine has been very reliable (244K miles)and haven't had to do more than preventive/routine maintenance. I'm finally getting oil leaks from original cam gasket and maybe front seal above water pump. It doesn't look there is gasket seal used to comfirm seal; just want to make sure before ordering gaskets and removing covers. Should I use gasket seal or not? If so what brand is recommended?
2. What is the function of the thermo fan clutch? My temp gauge is always in the normal range, but since moving to AZ the cooling system seems to boil over out the expansion tank.
ANSWER: John, seal with a very light coating of RTV Black sealer. Smear it on very thinly to both sides with your fingers.
The fan freewheels (no lockup) until a certain air temperature under the hood is reached. @ 80c Then the clutch locks the fan to the pump shaft for increased airflow through the radiator. Usually when sitting still, seldom on the highway. They do this for more power and fuel savings.
Mark
---------- FOLLOW-UP ----------
QUESTION: Mark- Thanks for the input. What are your thoughts on the cause of the boil over? I am replacing the tank cap(its the original);and there is no water vapor/steam coming out the exhaust pipe-blown head gasket. There is some leakage around the top portion of the water pump, and am replacing the pump and gaskets.
Answer John, cap replacement is a good idea. Fairly regular for failure at that mileage. Hook a pressure tester to the cooling system and watch pressure. You may have the small beginning of a head gasket going bad? It won't smoke out the tailpipe for a while because the engine is burning it all clean. It still could be pressurizing the cooling system though, depending on what gasket passage fails first.
Sorry for thwe possible bad news.??
Merry Christmas
Mark
