Happy holidays everyone!

My 2006 XK8 coupe is the best gift I ever got myself, but I am bugged by some noises. First is a rattle that sounds like something plastic in the "eyebrow" padding that covers the dash. It's a continuous rattle at around 40 mph, also comes and goes at most other speeds. The noise seems to come from directly above the center vents and it goes away if I push forward (towards the windscreen) directly on the eyebrow with my hand.

I'm also experiencing noises from my trans - a slight clunk sometimes that seems to occur when the trans downshifts into first, and a whine at around 60 mph. The whine is not very loud, a medium pitch, and it continues for about 1-2 seconds, stops momentarily, that comes back.

Any thoughts on dealing with these would be greatly appreciated!

 

Your dash rattle can usually be traced to one of the plastic air vents bouncing around in its sockets at certain speeds. Most folks who decide to silence these vent rattles do so with very small pieces of foam glued to the vents to absorb the vibration. Some folks just stuff the foam down into the offending vent, but there's no guarantee it will stay where you put it. Some disassembly may be required to place that foam exactly where it needs to be....

Your transmission clunk may be a variation of the infamous "ZF bark" / "ZF squawk", but that usually occurs on upshifts, not downshifts. Still worth researching, though - search this site using "ZF 6HP26 transmission bark / squawk" as your key words. Fresh ATF fixes the ZF bark / squawk - that seems to resolve the issue at least 95% of the time....

Your transmission whine may be a different issue. The 2003-and-newer S-Types use the same ZF 6HP26 transmission as the 2003-and-newer XK8s/XKRs. A few of these S-Types have been known to whine at about 60 mph. There is a Technical Service Bulletin that addresses this issue - TSB 205003. I believe it calls for the replacement of the rear axle assembly and axle housing bushings. I do not know if this TSB also applies to the XK8/XKR, but you may want to research it....

 

This thread provides several options for the dash rattle: https://www.jaguarforums.com/forum/x...nts-faq-45338/

I have found the 5/8" foam backer rod available at home depot is the easiest and is effective: MD Building Products 5/8 in. x 20 ft. Gray Caulk Backer Rod for Gaps and Joints-71506 at The Home Depot#

 

I used 3/8 inch rubber fuel hose jammed up between the windshield and dash, one long piece as long as the dash, works perfectly, can't really notice it.

The 2-1 downshift clunk seems to be a normal thing. Others here have asked and answered. I have had this since I purchased my 2004 with 60k miles and was concerned initially, but it never has gotten worse, now with 98k miles, and others have said the same. I asked my mechanic about it too and was told they all do this. I think it is a ring and pinion slack adjustment in the differential, but again, I'm not concerned with it and don't want to fix something I now rarely pay attention to.

I can't really tell what noise you are experiencing. There is a lot of info on the ZF6HP bark, which apparently is harmless, but can be resolved with magic elixir additive from Jaguar. Search for bark on the forum and see if that's the same as what you experience.

 

Thanks to everyone for your thoughts. I am amazed at the depth of knowledge that's available to me on the Forum!