Hello first post here. I just picked up a 1998 XK8 yesterday and it sounded perfect and had no issues. Today I went to drive it a bit and it sounded like the linked video. I’ve done some research and it sounds like how the timing chain is described to sound but he showed me receipts of it being changed out for the metal guides. Of course people can lie and it could have been fake but I just want to see what the opinions of folks with knowledge of the vehicles think.

https://youtube.com/shorts/b9pTSEorND0?si=4ewz26plVqKJPR8L

Let me know what you think or if there is anything else I can provide.

 

I couldn't get video to come up. Get someone to watch the alternator pulley on start up. Some are sensitive to some of the aftermarket serpentine belts. They can jump and make a knocking noise on start up then smooth out in a moment or two.

Jack

 

Try this link, apologies for not making one before.


In the meantime I will check that as soon as the sun comes back up. Thank you for your reply.

 

Videos are helpful but oftentimes they enhance sounds in such a way that makes diagnosis with video alone somewhat difficult. That being said, does it stop after it warms up? It almost sounds like an exhaust leak to me. I have a Jeep that sounds just like this and I know where the leak is but it's so tiny and extremely difficult to fix so I just deal with it and after about 4 or 5 minutes it expands because of heat and then stops. It doesn't really sound like a timing chain issue to me, which is more of a rattle than a rhythmic tick.

 

These cars are prone to having piston slap noise which is harmless if you don’t drive it hard until the car has fully warmed up.

if I were in your shoes I wouldn’t depend on an Internet forum to diagnose a noise which could be nothing, or it could be be something serious .

take the car to a Jaguar specialist and get a hands on determination.

thats going to give you the best outcome without driving the car (what may be) a harmful amount.

Z

 

a cheap harbor freight stethoscope can be very helpful in pinpointing noises like alternator or water pump noises.

Jack

 

Remove the serpentine belt and run the motor briefly ( < 1 minute ) to check if it's something in the accessory train.
Does the noise go away?

 

So I listened again on my PC instead of my phone this time and I just realized I hear 2 actual sounds in the video. A standard ticking, but then I do hear a syncopated more of a hollow rattle sound. Quite faint, but I can hear it. Which noise are you referring to? I agree with the sentiment to remove serpentine and run it briefly to see if the noise goes away.

 

I agree. It can also be helpful in checking for timing chain rattle or slap. Even if the upper chain tensioners were replaced, the lower primary chain guides and tensioners are prone to failure due to the plastic parts of both becoming brittle and cracking. On my '98 XK8 they went at 85,000.

Good luck, Rick

 

A person would have to be the biggest tightwad and insane person to not do all at the same time!

 

True, however; removing the front cover alone can be an imposing task, due to the threat of broken bolts and the need to remove the crank damper and it's woodruff key. Easy to put it off, but you,'re right, there's no time like the present.
Best, Rick

 

Both - Nothing heavy, so could be water pump or PS pulleys, possibly. Serpentine off is a quick $0 check there's nothing amiss there.

 

I had a very similar sound come up a few months ago and had all kinds of bad thoughts
As suggested I removed the serpentine belt and voila - no noise
It turned out to be 2 of the 3 bolts on the power steering pump pulley that had backed out - one just a little loose and the other required about 3 rotations to tighten
Sometimes we get VERY lucky

 

Here’s a link to the car running with no serpentine belt


Unfortunately I’m assuming the worst. Does it sound like something more nefarious than the timing chain? I can take it to a jag specialist I just don’t know if it’s even worth the money for a diagnostic fee. Should I just start shopping for a replacement?

 

I'm no expert, but if that's without the belt on, I'd be looking inside, based on my own limited experience. It doesn't require a big tear down to find the problem, and it's doable as a DIY project, if it turns out to need work, but there's lots of help here, and if you're up to the challenge, it's not necessary to give up. I can promise help, and there are other more experienced members that I'm sure will chime in too.

Wishing you the best,
Rick

 

It's always difficult to tell from a video but I would continue with elimination of the easy stuff and it could be one or both variable valve timing (VVT) solenoids. It does not sound like a cam chain issue to me.

An OBD scan might well provide a diagnosis as the ECU should detect the error in valve timing.

I suspect that you could simply disconnect the electrical connector, first one side and then the other, and see if that makes any difference but you should do some more research first, or wait for someone else to comment, as this is not a problem I have ever encountered.

Richard

 

I guess it depends on how good the car is otherwise, and how deep you want to go. If you are not in a position to DIY, then you could run into big bills very quickly.

I wonder if something is awry with the previous tensioner replacement job? It's not too involved to lift the cam covers to investigate further.

 

I did not think to post this until you found the noise.

 

I am pretty mechanically inclined, I plan to DIY everything I can on her. I disconnected the VVT solenoids and the sound didn’t change so this weekend I will take the covers off and get a better look.

I may need to source a replacement engine to keep in the shop in the meantime in case I can’t figure out the source of the noise. Does anyone have a good place in mind to source them from? I’m willing to travel/ship it.

Also I searched around East Texas and couldn’t find a euro shop that was willing to work on a car this old (which is baffling since I was offering to pay just to get a diagnostic from the only two euro shops in Tyler). So I’m stuck with attempting on my own anyways.

 

There’s a good source for all
kinds of used Jaguar XK8 / XKR parts in Texas just outside Dallas.

https://nomaautoparts.com/

they have many many parts not listed on their website or on their eBay store.

So call them for the scoop on various engines they have in stock. They also have transmissions.

Z