All-

I did some searching in the archives and what I found was pretty inconclusive, so I apologise if I'm asking a question thats been beat to death.

My '88 560SEL that I rebuilt started making an unusual noise. It sounds to me like timing is off. I did a top-end rebuild/valve job on the car 1,200 miles ago and while I was there replaced the timing chain, the top rails etc. Now, I know, I know, I should have replaced the timing chain tensioner then, but I didn't. Now my car is making some internal tapping noises which sounds like loud wood-peckers going to work. To me it sounds like the valves and pistons tapping just enough to make noise since it's intermittent. Since I've never had this problem before I'm not sure if my audio diagnosis is correct, so I'm seeking to tap into some experiance.

-FACTS-

First off, I replaced the timing chain tensioner and ran the engine for 1 minute. The knock went away at first and then it started to come back.

The knock is coming from the passenger's/right side of the motor only

During the valve-job, the heads were machined flat.

origional 0-degree woodriff keys used in both cams



When I ordered the new timing chain tensioner, I also ordered a couple of woodruff keys guestimaing at different offsets just in case, besides I needed to make $100 for the free shipping and it was a good excuse

Any ideas? Anything else I can provide to help in getting pointed in the right direction? I don't want to take the valve-cover off, but if I have to I have to...


Thanks in advance!


Scott