I have a knock that just surfaced tonight. The oil level is good and it is clean. The nearest I can tell the knock is coming from the bottom end, it seems to be loudest where the balancer meets the block but I can't find anything loose. I'm guessing it's a rod but I'm not sure. It is loudest at idle and goes away when I bring up the rpms, I thought a rod knock would get louder when the rpms went up. Any ideas?

 

How is your oil pressure? (if you have a gauge)

Don't jump to conclusions at least until you check the flex/flywheel and the torque converter/clutch to make sure they are not coming loose or are cracked. Many "engine knocks" originate from here causing many an engine to be pulled needlessly.

 

Well this is embarrassing but I figure I'll post the problem in case somebody makes the same mistake I did (doubtful). It was the crankshaft pulley. One of the bolts came loose causing it to wobble against the balancer but not so much that I could see the wobble. I tightened it up and the knock is gone. I feel stupid but at least it's not a rod!

 

Wish I was as lucky as you. This happened to mine and it had less than 50 miles on it.

 

Don't feel stupid, feel happy and go give that car a good wax job.