2000 XKR 73k. I have been getting an intermittent noise on cold starts. It only happens when cold, probably about 1 out of every 5 cold starts. I have linked a video of it below. Any ideas?

 

The noise has not impacted performance as far as I can tell. I did the secondary tensioners about 6k miles ago (the old ones were in pretty good shape). It almost sound like the timing chain is rattling over something, but I am not sure. They noise goes away quickly, so I don't have time to start it and then isolate where the noise is coming from, plus I never know when it will happen.

 

It sounds lightweight and plasticky, like something rubbing against plastic fan blades.

I'd inspect the whole belt run, looking for something rubbed or hanging nearby. It's also a good idea to check how tight your steering pump pulley bolts are. Mine caused a terrible sound a couple weeks ago.

 

Thanks for the ideas avt. The plastic fan blades are not spinning when the noise occurs. The power steering pulley is tight.

I hear what you are saying about the plastic sound, the weird thing is it sounds metallic in person. The iphone microphone might not be doing very well picking up the sound correctly. I just fired it up and took another video. It did make the sound this time (more metallic than the video), but when I listen to the new video it sounds the same as the first one. The noise is scarier sounding in person.

 

have a second person start the car while you isolate the noise. If you cant find it, make sure your oil level is fine, coolant level is fine, just keep driving, it will only get worse

 

Thanks aode, at this point that is pretty much my plan. Fluid levels are all correct. I just wanted to make that I wasn't going to do any further damage by running it (like skipping the timing chain or something). The noise itself does not really bother me, and the performance seems fine, so I will probably just keep driving it if I can't find the source of the noise.

 

Not to be overly cautious here, but if that sounds more metallic in person, it could be chain slap from bad guides.

Primary tensioners letting go aren't typically the engine disaster that secondaries are, but why take the chance on shrapnel in the engine bay? Not to mention being stranded on the road. You are both correct in that "it will only get worse". Question is, when and how.

I'd keep checking it out or have a knowledgeable Jag mechanic look at it.

 

The timing chain was the first thing that came to mind when I first heard it. However, I thought it would be weird for the guides/primary tensioners to be bad since the secondary tensioners (usually the weak link) looked pretty good when I replaced them 6k ago. Also, the timing chain rattle videos I have found sound different.

I guess I am unlucky because every time I have had someone around to fire it up, there has been no noise. I will have a helper on Tues and Wed, so I can try again then.

I was thinking it might be a pulley bearing, but I'm not sure what that sounds like. I will get the stethoscope on it Tues.

 

Pulley bearings ususally make either a growl or squeal for a short time till they warm up some.

Just guessing here but one thing that does come to mind might be the belt tensioner. If the springs are tired could it be that it's chattering. You should be able to watch it while someone else starts the car and see. My experience, though, has usually been that the belt will get spit off when a tensioner gives up, so maybe it's a long shot.

You might also try taking the belt off so that none of the accessories are spinning.

 

 

Thanks Jag and ccfulton. On Tuesday I will confirm if the noise is coming from that area. If it is I will pop the belt off. If it still makes the noise then that should narrow it down to something the timing chain is contacting.

I will try to post an update next week.

 

A loose chain will always make noise at idle and never go away,so will a failed tensioner.

I would remove the belt, start it up, and see if the noise is still there, our belts are very easy to remove

 

It sounds like the timing chain hitting something until the tensioners pump up (they are all hydraulic). You need to pull the valve covers and check it. Just because the tensionrs were replaced doesn't mean that they couldn't have a problem, and it could be the primary guide and not the secondary. I would not drive this car anywhere!

 

Hi Maxer, first of all I am envious. You have such computer a video skills. Also sorry to say I do not like the sound. Not speaking of Jaguar engine experience, however my domestic engine experience tells me it sounds like the chain hitting the alum housing. This tell tale happens when cold, first start up. Chain slop till everything aligns. If you have had the chains looked at , I would run back to the tech to have it checked. Rich

 

Timing chain issues is my guess. My Mini Cooper I had before the jag now did the same thing, hit and miss for awhile but then more frequent as the chain stretched do to bad tensioners.

 

It could be something as simple as making sure that your Oil Filter has a Anti-Drainback Valve.

This could result in a delay in Tensioner Activation resulting in Chain Slap at Startup.

OEM Jaguar Filters have this Valve.

 

Thanks for all of the suggestions. I have a NAPA gold oil Filter that I think is the WIX one with the valve, but maybe I should replace it with OEM. I have not been able to get it to replicate the sound the last few times I tried it. I remember looking at the timing chain when I did the secondary tensioners, and it looked fine visually (not sure if it was stretched).

I don't want to do the primary tensioners myself. Is it worth it to redo the secondary tensioner job and verify that the oil holes for the tensioners are primed? Or should I just have a tech do the primary tensioners?

 

Hello,

I recently noticed a loud metallic knocking on cold startup when the car has been standing for a few days. It does not happen when standing only over night. The knocking lasts about a minute. Otherwise the car runs very smooth when idling and during driving.

Here a video

You Tube

I read a few threads but I am not able to clearly identify the sound since there are seldom videos of the different sounds available.

Both belts and all pulleys have been renewed recently. I am not sure about the chain tensioners as the previous owner did not have any documentation whether they have been changed.

In some threads it was also suggested that this could be from the supercharger.

I would be grateful for any suggestions.

Best regards

Marko

 

I wonder...
It seems random.
Could it be either the accessory or supercharger belt not running true and then snapping back into place?

Try removing them one at a time and running the motor for a few seconds from cold.

 

Thanks for the input michaelh, I will try that. You mentioned that it’s random - would the chain temsioners sound more “even”?