2007; 4.2 XKR Intermittent Start-up Rattle

[Patrick Bateman]

You can hear it here just after the car starts-

https://youtube.com/shorts/M5-QIKn4gYE?si=LEceG6Up...

I have a thread going here to save repeating everything - https://www.jaguarforum.com/threads/4-2-xkr-interm...

Only happens infrequently and I'd have thought anything relating to the timing chain would make itself known on every start. Seems to happen most often when the car has been sat for just a few hours (think heading out from work at lunch). Don't think I've ever noticed it when the car has been sat overnight or when warm.

Any input appreciated.

[reddiesel]

Sorry Patrick , difficult I know but it doesn't strike me as a rattle . Have you done anything with the scanner to see if there's anything showing ?
I would pretty much bet the house its not chain related .

[Lincsls1]

Could it be an issue with the starter as it disengages? Just an alternative idea.

[Patrick Bateman]

reddiesel said:

Sorry Patrick , difficult I know but it doesn't strike me as a rattle . Have you done anything with the scanner to see if there's anything showing ?
I would pretty much bet the house its not chain related .

I'm hoping not, post #14 in my jaguarforum thread filled me with some dread but I'm not aware of chain/chain tension issues that would be so intermittent and, so far, never when the car has been left overnight.

No engine codes. Is occasionally a little lumpy at idle on a cold start but it has been doing that for long before this noise appeared and seems to run fine.

Edited by Patrick Bateman on Sunday 9th February 22:08

[Patrick Bateman]

Also, here's a clip I took of the engine running, there's no rattle as such here like when the car is started-

https://youtube.com/shorts/XmqnF28Hfns?si=i-9mBOzZ...

Edited by Patrick Bateman on Sunday 9th February 22:39

[sean ie3]

I don't know this engine, but it sounds like valvetrain to me.

[snafu10]

Had a slight rattle on start up when i owned my xkr 2007 used Tech 4 oil flush on oil change cured my have been a sluggish tensioner worth a try 17.00 a bottle

[Patrick Bateman]

Still no real change on this, never from a properly cold start and seems intermittent after leaving the car for 4 hours or so. Car's got its service in a couple of weeks so asking the mechanic to have a look/listen and see what he thinks.

If it is a tensioner, what's the minimum amount of work you'd be talking?

[ShortBeardy]

What does a failing supercharger coupler sound like?