I have a 2000 mustang gt and I was wondering if someone could help me troubleshoot my issue. I have a pretty loud knock that comes from the back passenger side of the motor. It doesnt really effect the cars performance it just sounds terrible. When its cold and first started it wont make the noise but as soon as its a little warmed up it comes. It doesnt do it much at idle but as soon as the rpms rise it happens. Was wondering if anyone had any clues to what my problem might be.

 

first off is the cel on. If not are you sure it's a knock or is it a valve tap. Also depending on what type of gas it could be octane ping to. How many miles are on the car.

 

You need to post in the correct forum next time.

 

..moving to tech.....

 

Does your car have headers? I had a similar problem with mine. I replaced the motor mounts & the knocking went away. I am not saying its that but that is another thing to check for. If you need to replace the motor mounts make sure you get some good quality ones or the knocking will come back.

 

sounds like a rod bearing to me, mine didn't make any noise at idle, just after ~2k rpms

try unplugging one coil pack at a time and seeing if it goes away, if it does, spun rod bearing and I wouldn't drive the car anymore until you do this

 

Check and make sure there is not a exhaust leak where the manifold bolts to the mid pipe. There is a gasket that goes bad and to untrained ears sounds like engine knock when it leaks