Knocking sound when engine cold

[Joseph80]

I attach a copy of Youtube video of my XK8. The clicking sound has increased over the months.

The noise seems to go if I rev it up but once the engine settles down to an idle, the clicking starts again.

https://www.youtube.com/watch?time_cont ... 1ot-Ry_1ZA



I would appreciate any advice.


Cheers
Joseph

XK8 1998 auto 130,000 miles.

__________________
Joseph

[Andy P]

Hello Joseph,
If you haven't already checked to see if you have the upgraded tensioners I would do so rather quickly.
From your video I see you have the upgraded thermostat housing so that's a good sign .
If it hasn't been done,at 130000 miles it would be wise to replace the primary and secondary tensioners as well as the chains.
Easy to check,just remove the rocker cover's.
The upgraded tensioners will have an alloy body.

Upgraded Top Tensioner

Good luck and take care.
Andy

[mike020150]

That's a pretty loud knocking noise! The fact that it disappears hints that it could be related to operation of the VVTs (variable valve timing units). When worn, the oil drains out overnight and is not replenished with pressurised oil (needed to change the valve timing) until the revs reach a certain value. As a real stab in the dark, are you certain the engine has been filled with the Jaguar recommended grade of oil? The wrong grade could have an adverse effect on VVT operations. Mike.

[Joseph80]

Sorry for the delay I have been away.

I will defo check this out and keep you updated, again thanks for the advice.