What does a knock sensor do?
My car was running hot ,I had a new radiator and
radiator fan installed... still ran hot so took it to
someone else and was told I may have a cracked
or blown head gasket but no one will touch it! How
do you know if your head gasket is blown?
The knock sensor is like a microphone. It listens for spark/knock. If your engine starts knocking or pinging it sends a signal to the computer. The computer then retards ignition timing until the knocking or pinging stops. To test for a head gasket blown into the cooling system, pull the oil dipstick. If there's white milky "goop" on the dipstick that's a pretty good indicator of a blown head gasket. White billowing clouds of water condensation from the tailpipe is another good indicator. You can, with the engine cold, pressurize the cooling system with a cooling system pressure tester. Then start the engine. If the needle on the pressure tester's gauge bounces, the head gasket is blown. HTH. -Jim
A compression test might show that the head gasket is bad. Also you will not always have coolant in the oil as sometimes the coolant goes straight out of the tailpipe.
Search Chrysler PT Cruiser Questions
Chrysler PT Cruiser Experts
#3Kelly Little AshfordReputation1,390