Postby smj999smj » Wed Jun 26, 2019 1:38 am
Couple of things you can try. Use a mechanic's stethoscope to try and pinpoint better where the noise is coming from. Remove the serpentine belt to make sure it's coming from the engine and not one of the drive components. You probably already check the oil level. A water pump, which is timing chain driven, with a bad bearing, could make that noise. Hopefully, it's not something internally in the engine. My thinking is the knocking triggered the knock sensor to signal the ECM, which, in response, cut the power to the A/C clutch, which is why your A/C system stopped working.