I recently change the spark plugs on my 2000 323i with Bosch Platinum 4s. The car is running fine, maybe even smoother but I hear this very light sound coming from the engine. Sounds almost like a cricket. Can only hear it while in drive or reverse. The car is running perfectly and no warning lights. Should I ignore this or what? Any ideas???? Thanks in advance!

make sure the plugs are tight. they might have backed off and now you have a leak.

Thanks, I am gonna check and make sure the spark plugs are all tight. I am pretty sure they are though. If they were loose, would it misfire or would I lose power and have a rough idle? The weird thing is the engine actually sounds better since the spark plug change yet this sound remains. What the hell could it be?

Any techs on here have any idea?

Ok, I just finished checking the spark plugs. They were indeed not tight at all. I tightened them properly now but still I hear this sound. Could I have caused any damage?

you're OK.

Fast4d, do you know what it could be? The engine is running perfectly.