Hello guys, im new here.

I'm Curt, 25 from germany and bought last week my first Jag, a 2008 SV8 with 150000km. The car is in good shape, but I mentioned a kind of knocking or tapping sound when the car is at idle. It is there when the engine is cold or warm. You can hear it at best from the sides so it's more likely, that it comes from the back or bottom of the engine. The sound goes faster when reving, until 1250rpm, then it's away. When in D or R while pressing the brake it's louder than in N or P.

I really looked at ALL threads in the internet, but it seems like that nobody got this problem...maybe someone here got an idea and can help me....thanks!

Video of my car at idle:
Cheers, Curt

 

Aside from all the moving parts in a supercharged engine, one possibility is an exhaust manifold leak, where it mates against the block. This is not unheard of on Jag engines. To confirm it run a smoke test pushing up the exhaust pipe but at a repair shop that understands that the exhaust valves need to be closed for that to be tested properly, and then rotating the engine to test the cylinders that were open prior to check status on all of them. This is specialized knowledge most places in the world but maybe in Germany you can find someone.

Overall though these are not the smoothest engines, yours sounds fine actually for the km and going on 15 years old.



not the exact engine but you get the idea.

 

Hey litteredwithfaults, thanks for your ideas.
I continued my search and ended up with the left (okey right when you stand in front of the engine) intercooler. Sounds weird but when you press a screwdriver against one of the ribbs and put your ear on the screwdriver you can hear a high pitched knock coming from there. Because of the slowness of the knock i would say something with the valve drivetrain...camshaft? tappets? valves itself? Anybody had this before? Any guesses are welcome. 😬