Hi there,

I am a more or less fresh owner of an XJR. Bought it for a really good price and with beautiful red color so there was no other way. When I bought it there was already a strange rattling noise coming from the engine. I was thinking (as I have heard the noise on other youtube videos already) that the problem is the supercharger coupling. It has been replaced today. THE NOISE REMAINS. During the exchange the supercharger was disconnected, the alternator, power steering and AC as well. The sound remains. Do you please have any idea what to look for next?

The video:

 

Possibly timing chain rattle. May need tensioners and chains. if it is the case, QUIT driving or running the engine. If it jumps 2 teeth engine damage will result.

 

It sounds a lot like mine did with a failed primary tensioner. Randy is right, stop running it, pull the valve covers and have a look.