malo012000

drop the pan and look around and see if you find anything but if its a spun bearing you wont see much so pull motor asap dont run it any more...

panamacity347

does this sound like a crank bearing or rod bearing

stanks347

If it knocks only at a low rpm it could be the thrust bearing in the crank. Sound like you gotta pull the pan.

joes90gt

This is a good way to help narrow things down BEFORE you start digging into your engine. With the engine at idle, pull one plug wire at a time.....if your knock gets quieter then you have a suspect spun rod bearing and then know what cylinder is laying down on you.

If you pull them all, one at a time, and hear no reduction in knock, then you need to start digging. Since your removing the spark, the cylinder won't fire, therefore having ALOT less load on that cylinder...that's why it will get quieter when it's a spun rod bearing.

Use this approach as a "direction" on where to start looking BEFORE you start pulling parts off. It can save you alot of uneccessary teardown and at least give you a start one where to look.

Good Luck!!

mustang queen

I would do what I recomended first > You said the noise was at the bottom rear of tyhe motor . With out checking further maybe the noise is actually in the bellhousing. Just trying to save you work . Main bearings rarely spin.

panamacity347

i wish i would have thought of pulling one spark plug at a time before i drained out the oil. i was thinking the noise could be in the bell housing but i did drain the oil a month ago and it was metallic gray so i have a bad feeling it's going to be a bearing