I have a ticking noise that stays in time with the engine rpm on cold starts, and disappears after driving 4 or 5 miles. The noise seems louder in the winter but still disappears when the engine warms up. My stethoscope shows it to be the loudest on the valve cover bolts near the back of the engine, and the noise is similar to a worn hydraulic lifter (of course it is Not). This is my 1999 XJR with a 2002 XJR supercharged 4.0, and no VVTs on this model. The timing chains and tensioners were all New with the engine swap. I left this 1999 XJR with the Jag Dealer overnight, and they heard the same ticking on the cold start - and offered no suggestions as to what the noise is, but offered to install New cylinder heads. I like the idea that it might be a fuel injector - or is that just wishful thinking?
Thank you,
Mike

 

Sounds like a valve clearance noise that goes away when the engine gets warm. If it isn't something that bothers you too much I would just live with it. If it does bother you you could have the valve clearances fixed.

Here is a forum link to the subject...............
https://www.jaguarforums.com/forum/x...ing-v8-198000/

 

My supercharged engine (1999 Daimler Super V8) does exactly the same thing (tick). I had this before and also after replacement of both heads (with excellent condition used heads), valve job, very careful valve clearance adjustment etc. I hear the ticking (by ear and with a stethoscope) coming from the LHS valve cover. It does not change with load (AC compressor on, gear engaged) but it does disappear (still cold and ticking at idle) with just a bit higher rpm than idle. When the engine warms-up to 88C, the tick is completely gone. I gave the engine some miles after the rebuild for the valves to "bed-in" but the cold ticking is still the same.

Now I am planning to do a check of all valve clearances and re-adjust if and where required. I suspect that the tick is caused by some valve clearances slightly out of range. It seems that this engine is highly sensitive to valve clearances, otherwise Jaguar would not have designed the valve shims to be in extremely small increments of just 0.015 mm. And it seems that the shims were initially in 0.02 mm increments, later revised to 0.015 - looks like it was done in order to solve the ticking issue with even finer valve clearance adjustment.

 

I forgot to mention that the valve clearances were the first thing I checked. None of the exhaust valves exceeded 0.010 inches, the intakes were all close to 0.008 inches. Not understanding why the noise is prevalent (with the stethoscope) only on back of the engine. The last time I saw an exhaust valve clearance grow on one of these engines, was just prior to dropping a valve seat. - In that case the tapping noise was there when the engine was warm. In this case the tapping noise Disappears when the engine is warm. The noise I can live with - not understanding if this is an indication of pending failure - is disturbing.

 

Run two batches of BG 44K fuel system cleaner through the gas tank. It sounds like injector noise to me. Normally, you should stay far away from snake oil remedies, but if the noise is from dirty injectors, 44k will fix it. Worked like a charm for me...I can’t explain it.