Rattling noise from engine, HELP

i have a weird rattling noise in the engine, its not the valves knocking and it drives fine just when idling and such the video makes it sound louder than it is. the video below makes it sound different:

http://www.youtube.com/watch?v=m7H4D...ature=youtu.be

Linky no worky.

But have you taken a stethoscope (or just a piece of hose to the ear) and tried to locate the sound?

If you have not done so yet, take the fanbelt off and try running the engine (cold and very briefly of course) that way. If the noise goes away you know it's something belt driven, and while the belt is off you can spin things and check what you hear. In my experience XJ water pumps can make quite a racket before they leak. The design is very good, in that the impeller has a concave profile that rides tightly on the convex pump housing and keeps it centered, and it can run well for many miles with a horrible bearing.

It says video doesn't exist.

Reclipse said:

It says video doesn't exist.

Click to expand...

does this work?
http://www.youtube.com/watch?v=m7H4DN4EAHU

Hard to say for sure, sounds like sticking lifter-loose rocker arm noise, but seems too loud (you said the video was louder than the real thing though).

I agree with Matthew Currie, remove the serpentine belt and run the engine to isolate the belt driven components.