Well it sounds like my friends turbo... I only wish.. but its just a little annoying. I have what looks like a hairline crack on my exhaust manifold at the weld. The 4.0 tick is also really loud. Anyway I could check this. I don't have the money for a new manifold.

 

It doesn't happen all of the time too. the engine seems like it has to work a lot harder when i push down on the break pedal..i just want an over all quieter xj.

 

It would take Sherlock Holmes to track down all of my "noises".