Gordo--where exactly are these (not sure what a shark fin grill is)? Are you talking about access from inside the cabin to these bolts?

Doug

 

+1

 

On top of the dash, two are under the speaker enclosure that pops off for access. (They are not under the vents, as previously noted in error...) Pop off the covers and there are bolts underneath. Also at the the center of the top of the dash. Remove that cover too.

 

Well I did a little exploration today. Curiously the toughest part was removing the wiper arms. The become pretty well locked onto the spline so you really need something like a gear puller to pry the arm off the spline. The battery cable remover I happened to have worked well for this.

Then it is pretty easy to remove the screws securing the plastic cowl. Naturally, one of the cheapo plastic inserts for one do the screws fell apart.

After lifting the cowl I was able to see the torx screws that secure the diagonal braces. Unfortunately, I couldn't find my Torx 50 bit but it was obvious to me that both screws were tight so I don't really think the brace is the problem.

I put things back together and have another tip here. Make sure you reconnect the cowl drain hoses (these are at each end of the cowl at the underside). The one on the driver's side can be pushed on after the fact but there is no way to fit your hand anywhere to secure the one on the passenger side once the cowl is installed.

Next possibility could be that brace for the dash that I asked about in a previous post or maybe something else behind the glove box. I think what I will do is leave the car again one day for the local guy to do some further exploring during which time he can also adjust the rear quarter window on the passenger side to eliminate the gap between the quarter window and the passenger window.

Doug

 

On my '97, the two rubber drain tubes have 3" long rubber tabs w/ a slot on the end that is used to pull the tubes up into the cowl drains. The slots on the ends fit over a tab on the hood latch and secure the tubes in place. g.

 

Yes--I had those same rubber tabs. That is what saved me for reattaching the passenger side tube.

Doug

 

Just a quick update of sorts. I stopped by another local shop and had one of the mechanics take a drive with me down a street with speed humps. He heard the bump sound instantly and also thought it was coming from somewhere inside the car rather than outside and was indicating the area behind the glove box.

The next step would be to leave it for the mechanic to start removing whatever is in the way to get to the vicinity of the sound. It would be nice to have a specific "destination" rather than ad hoc tearing apart of the interior.

Does anyone here have any insight whatsoever as to what parts or pieces that might be loose that one might start looking for?

Thanks,

Doug

 

Also--look at the thread I found from 2009:

https://www.jaguarforums.com/forum/x...999-xk8-15118/

The first post/question is:

I have a "thumping" sound coming from behind the dash. A Jaguar technician said it was a common problem, a clip which holds the ?? has come lose. Remove the 3 screws (under the 2 speakers and the center tab) then remove the top panel.
Well I did that but nothing moves. Can someone help?
Thanks


Sounds like my situation and there was never a solution posted to this "common" problem.

Doug

 

Sorry to chime in late on this but my car also developed a very similar sound @ approx. 30K. (a long time ago for me) The sound was almost like a racquetball deep in the dash or, I guess now that you mention it, some wood blocks knocking together. Turns out the dealer replaced the shocks, or dampers, under warranty. I do not believe the damper itself went bad but the lower bushing was more the culprit. It may be worth a look.

 

The first mechanic replaced the sway bar bushings and also lower bushings and the second time I brought it back he looked at the shocks and whatever else he could see when the car was up on the rack. He also agreed that upon listening again it sounded like it was coming from inside the car and talked about removing the console.

So now at least 2 different mechanics concur that the source seems to be the interior under and behind the dash but other than a dash brace that shows up in a schematic I posted previously, I was looking for some expert insight as to where the mechanic should start looking and what should he be looking for.

Doug

 

I never had the problem on the interior so cant be of much help. I was away from the site for a while but see you got in there. I sure wish you would have had that T50. When I had that noise caused by the engine compartment cross-braces it did not sound like it was outside of the car. As illogical as this sounds- it sounded like it was coming out of the passenger side windshield. The brace was not "hand-loose". You can imagine the force a car exerts when it hits a bump. Even if you can't move it by hand it can move under that force. With all the people who have looked at your car I would to think they would know better but as an order-of-operations I always like to definitively rule out the easy, cheap things first.

 

I have an update on the noise. The more I hear it the more it really does sound like it is coming from the area of the upper brace on the passenger side. I had mentioned that when I try pushing or tugging on the brace it felt tight. But today I had the brilliant idea of first loosening the nut on the shock/strut tower end as I figured that could be just tight enough so that I could not easily move the brace. Sure enough once I loosened that nut I could generate a clicking noise by pushing and pulling on the brace which clearly was coming from the other end of the brace.

So I pulled off the cowl/plenum cover and got out my T50 socket. The T50 nut already felt really tight but I put my back into it and was able to tighten some more (but only slightly). Unfortunately I only had my 3/8" ratchet wrench so the amount of leverage I could apply was limited. Still I could not budge the T50 bolt any more.

I closed things up and drove the car around. The noise is still there but not as consistent. I guess with a longer/heavier wrench the bolt could possibly be tightened more. Or is there a way of jacking the car to relieve pressure on the brace which would enable more tightening?

Doug

 

It is probably a good thing you only had a 3/8" drive. You do not want to snap off the fastener. The brace is NOT pre stressed. Meaning it is tightened as the car sits normally on the ground w/o any part of the car being jacked up. IMO you should be able to tighten that bolt easily w/o resorting to a breaker bar. I'd limit the tightening to not more than 50 ft lbs. Make certain the surfaces are clean and free of rust.

If you want to confirm that the noise is indeed this brace, then remove it altogether. Then see if the noise persists.

 

Hey Gordo--you are right of course. Right after I did the previous post it occurred to me that even if there were pre-stress (which there is not) I would have already relieved that by loosening up the bolt at the other end on the strut tower.

In fact to test if the brace is the noise I probably do not need to remove the brace but just loosen or remove the nut on the strut tower end. Is there any harm in driving around with the brace removed/loosened?

Doug

 

No harm driving around with it removed, or loosened. If you don't want to remove the windshield finisher again, then just remove the bolts holding the brace from the shock tower, get it off the studs, and wrap it in a towel to cushion the exposed brace end.

 

Doug,
Last year my car developed the same quiet little clunk you described. Drove me nuts. I was certain it was inside. Took off console, opened the dash, looked everywhere. Checked the braces. Replaced the sway bar bushings. Still there, and only on certain small bumps. Made me crazier than my tinnitus. Eventually that sound developed (at least I think it was that sound) into a full-fledged metal-to-metal clunk. Turned out my upper control arm bushings were toast. Had them replaced and the car is blissfully quiet again. Worth checking.

 

Yes, Upper control arm pivot bolts, and related bushings are notorious for wearing out and being the source of clunks and clacks. That would be the first place I checked when trouble this type of front end noise.

 

Do you guys have a photo or schematic sketch of exactly where those are? When I first brought the car in to the local mechanic for the sound, he replaced lower bushings (wishbone bushings?) and that did not help. I brought it back in and he claimed to look at everything suspension-wise and did not find anything obvious. So are the bushings you guys are talking about something that can be seen or discovered to be bad by grabbing things and jiggling or do you have to tear a bunch of stuff apart?

Thanks,

Doug

 

Look for deterioration of bushing first. Then with spring unloaded, ascertain the fit between the pivot bolt outside diameter and the aluminum subframe crossmember holes through which the bolt is inserted is a tight and solid fit. The bolt can wear an elliptical pattern in the crossmember.

 

Hi,

Here is a diagram for you that may help with seeing the various bushes.

I had an experience with a knocking noise similar to yours, up on a ramp checked all the bushes etc... and everything seemed fine, however rather than just test the joints with a bar as you would normally, it's also worth pushing the outside of the actual bush to see if it's solid.

ie, when you test with a bar, often the leverage you can apply is not the same force as you get even at a low speed when driving and all can seem ok.

In my case the lower arm bushes were shot, when you pressed them with a screw driver directly on the outside , they simply collapsed, the outside of them looked fine but there was no bush left underneath .

It was frustrating and not until it reached a point of checking every bush extremely carefully did I find it.

XK's are sensitive and even more so if you have a convertible, I would say it's worth getting it up on a ramp again and re-checking because it does sound like a bush.

Best of luck....