Hello all, I have a 1999 XJR X308. I was on my way to an appointment and noticed as I accelerated I could hear a slight knocking as my revs went up. The knocking is not present at idle and goes away at the shift points. I had no oil pressure light or overheating. I was about 2 quarts low when I checked. When I filled up the oil and started it again I heard a loud metal to metal sound. I drove about 5 miles and only heard the knocking as I reached the shift point. Any ideas?

 

Please tell us that you checked/replaced the timing chains/guides/tensioners in the engine.

 

Yes, when I had the SC off I replaced the cam covers and checked the tensioners.

This is the only close-up i took, it's the left side.

 

It's also knocking at startup now. It goes away and comes back around 2k rmp.

 

Could this be my SC? When warm and the idle is low it knocks. Increase the revs and it goes away increase more, past 2k and steady knock. I had the snout and bearings done and the rotors coated. Could it be the rotors?

 

If you had an aftermarket solid SC coupler installed (instead of the genuine spring-loaded one), it is possible that the knocking comes from the SC. Remove its belt and run the engine to diagnose.