My 99 XJ8 has 88,000 miles and I have had it for the past year and since 83,000.

During cold start up I get this sound which resembles the sound you would get if you had a faulty hydraulic lifter, or in pushrod engines excessive tappet gap. It is not as pronounced and has a much more rapid pace. Maybe even similar to the sound you would get if you back pedaled a bicycle while standing. I mean the sound from the ratchet mechanism of the back sprocket.

The secondary tensioner(s) have just been replaced.

It seems to be temperature related or that simply in cold weather the engine spins faster on startup. The noise lasts under 2 seconds.

Yesterday when starting my 02 XK8 with less than half the mileage of the XJ I heard a similar sound but not as strong or as pronounced. I am running Mobil 1 0-40 in the XK and 10-40 High mileage in the XJ.

Is this something to do with the variable timing components? I believe I read something to the same effect in a thread here.

 

I have waited all day for someone more specifically knowledgeable to offer an opinion before I chimed in. While I have never experienced the VVT 'chatter' or 'ticking' it is usually described as a valve lifter type of sound. And a heavier weight oil is the recommended solution. Try a 'Restore' type of additive and see if that resolves the issue.

The other question I would have is did you, or whoever replaced the tensioners, replace the bolts along with the tensioners. The plastic tensioner bolts are longer than the ones for the metal tensioners and bottom out before they effectively seal the oil channels.

From your description sound more like a tensioner issue than anything else.

 

its vvt tick. like an air tool, the vvt has vanes. when stopped, it emties itself of oil . maybe its the vvt seal situated where oil goes in it . anyway the vanes will tick intil oil pressure is restored. i put a can of rislone in and tick is gone.

 

I would sure as hell chech this first!

"The other question I would have is did you, or whoever replaced the tensioners, replace the bolts along with the tensioners. The plastic tensioner bolts are longer than the ones for the metal tensioners and bottom out before they effectively seal the oil channels""

 

I must clarify, the new secondary tensioner (alloy body) have longer bolts. I think test has it mixed up. I've done the update to these engines a couple of times, bolts supplied by Jaguar are longer. In fact the same bolt as the cam cap bolts.
Plastic tensioner bolts are shorter.

 

OK, we have an honest disagreement with both sides based on memory of personal experience. Can someone, with bolts in hand, offer a comment. Inquiring minds need to know.

I will humbly apologize if corrected.

 

Sean:
Are you remembering secdondary tensioner bolts? I recall grinding the end off of 'em and I was definitely going from plastic to metal.

 

Thank you very much for the responses.

I replaced the tensioners myself however I have this habit of testing the length of any replacement bolt just to make sure for some reason they are not longer than intended.

So in fact I did screw in the bolts until seated and measured the height to make sure they were not too long to bottom out before the tensioners had seated properly. And I think the new bolts were marginally longer than the older ones.

I will buy and try a can of restore on my next and soon oil change.

This noise is annoying but by the sound of it if it is VVT chatter then it is just that “annoying” and nothing to be seriously concerned about.

Other than this cold start noise the engine run extremely smoothly and quietly.
Thanks again.

 

The Alloy tensioners require slightly shorter bolts. You can use the front cover bolts or cut a few new threads on the longer original with a 6 X 1.00mm die and trim a few mm from the end with a cutoff wheel and reuse the original bolts.

You can even use a small spacer on the top of the alloy tensioners and use the original bolts. Just make sure the tensioner is tight to the head before the bolts bottom out in the mount holes!!!

bob gauff

 

now you've got me doubting myself here! I'm going to check part numbers!

 

OK confirmed I'm completely wrong.
Short bolt part number JFB10607E (X4) M6 35mm. Use with Alloy tensioner.
Long bolt part number JFC106086 (X4) M6 40mm. Use with sh** tensioner.

Now I recall attempting to use the original bolts first time I exchanged secondary tensioners, they where too long. I had spare cam cap bolts that are 35mm. I even contradicted myself on these, they share the same part number....
Not to make excuses, but a lot has happened since I did one of these! Sorry to cause confusion.

 

I have the same noise on my 2002 XJ8 with 75k. Tensioners replaced in UT before I got it at a Jag dealer when the car had 65k. My noise is during a cold startup and lasts about 1-2 miles until the engine warms and then it is gone? Any recommendations? Should I call the dealership in UT and see if they changed the bolts? Or try a can of restore? I use Mobil 1 Synthetic oil as well. THanks in advance as I was just going to post this question myself.

 

Sean:
It's hell getting old isn't it? (Beats the alternative!)

 

Restore is $9, less if you catch it on sale. Can't hurt. Then you will know.

 

Well as suggested here I put in a bottle of Rislone in and by next morning the noise had disappears substantially.

Thanks everyone.

.
PS. I also did my own share of forgetting. The new bolts that came with the alloy tensioners (may have been the wrong one’s anyway) were too long They had an unthreaded section so I simply ground away that part and it worked fine.

 

a can of restore also helped me as well. The noise is still there, but is not as pronounced and does not last as long as before. I am thinking of switching to mobil 1 10w-40 next oil change and then i will report if the heavier oil helped