Background: The car has been progressively been making a clonking noise on the driver side front suspension. The noise is present while going over small bumps like road reflectors or washboard surface. Sounds like a wheel is loose (checked bearing etc... every is ok) and you can fell the rattle in the footwell where pedals are (frame bolts are also tight).

I thought it might be the sway bar and removed both end links to check for perished bushings - both felt and looked normal. After reading other posts and checking for movement in the suspension when I was able to confirm that the upper a-arm bushings were shot. I found a replacement set that I installed and while there replaced the steering rack tie rod ends. I also checked the ball joints and other bushing and all looked ok (though the large front ones are not very firm). So thought I was done...well not, the car still makes the same darned clonking noise. Other than tearing everything apart (or ditching the car) I am at loss what to do next!

One noteworthy thing, when I drove the car on the ramp I checked and I could see in the large mirrors I have on the wall that the wheel moves laterally a good 1/2 - 3/4" when the brake are applied. I confirmed that this is also happening on the passenger side (but that one doesn't make any noise)... I know that this isn't a race car with heim joints, but if this flex normal?
THX
Franck

 

I have the exactly same problem，hope someone can answer。。。。

 

Unload the sway bar before checking their bushings atop the crossmember. Either full weight on or full off makes it impossible to check 'by feel'.I've found that lifting the body up to gain access, then jacking the wheels/tires up to compress the suspension some allows you to pull & push the bar to determine if you can reproduce the clunk noise. Xk8 owners fight this regularly after 50-75k miles.

 

Thanks, I have put the car on the lift and disconnected both end link to check for looseness. It "feels" ok, i.e. slides up and down smoothly and doesn't appear to have any play (but access to view is tough). With that, the noise is only on the driver side and appears to diminish when the car is cornering under load.

 

Slides up and down? Quick video please.

 

I will plan to work on it over the weekend and will post the results. Decided that since the car has 75K miles I might as well replace all the bushings "while I am there" for both front suspension and sway bar... The only other thing I plan to do is switch the air spring around in case that is the source of the problem. As I was checking the sway bar bushing access (or lack there of) I noticed dried coolant build up around the area of the water pump (my wife has complained about coolant smell in the past), is that a common failure for this car?

 

I have a similar clunk from my LH front side on acceleration, and an idle vibration--I'm suspecting motor mounts are shot. Doing some searching on the forum other people have had similar noises/issues. Might be worth it to check your motor mounts.

 

i have a similar noise on my pasngr. side 2008 xjl w/47k .....most noticeable when making harsh rt./lft. steering corrections...or sharp speed bump at 10 mph.... car had new rack at 10k and front end bushings(not sure which) at 44k...i just bought the car at 47k.... have done all the normal checks to no avail...let us know what u find..thanks

 

That sounds totally wrong and something serious is up.. (at least to me!) Whole front end is mounted on a subframe, so if both wheels move together, it sounds like the subframe mounts. Having said that, I have never read a post on broken/duff subframemounts, but with all these bad roads, maybe it has to happen some time. Other thing is top wishbone possible snapped on one arm. Have you inspected the whole suspension ?

 

When you say" i found a replacement set" do you then mean NEW arm w. bushings.
These bushings are too soft brand new and I would NEVER waste any time with used ones since a very high percentage will make a clonk noise even if they look ok.
Mine where klonking and looked ok, just seemed a little soft when prying them.
Installed new (not available separate from Jag) bushings and no more front end noises.

 

I may have mis-spoken when saying "laterally" instead of longitudinally. The subframe is well secured and all the suspension component appear in good shape. I have a lift and have extensively examined the suspension using a pry bar and nothing is loose (now that I replaced the upper a-arm bushings), the only obvious thing it the large front bushing on the curved "wishbone" feels very soft and "flexy". That may explain the longitudinal movement under load...

 

..yes all the parts are new - the bushings can actually be found individually (even upper a-arm bushing which I got from Israel!!) - since I have a press it's a pretty straight forward job to replace them and quite a bit cheaper than replacing the whole part.

 

The very front bushing is the one that goes out and like you say it feels soft, I know you can get the bushings (Not from Jaguar) as i also have the upper bushings fom the guy in Israel and the front bushing I got on ebay.
The front bushing is installed a little different from what we are used to, as it is actually appx. .1 to .2 of a millimeter smaller than the hole in the arm.
If you look at the bushing from the side it is not cylindrical, it is pre crushed a little so the diameter is a little bigger in the middle than the ends, during the manufacturing process I assume the bushing is just put in the arm by hand and then pressed again to further swell the middle of the bushing, making it stay in place.
This would explain why Jaguar only sell the arm complete, as it probably takes a press bigger than what most shops have.
I got some shim stock and put it between arm and bushing in 3 places (120 deg. apart) and pressed the bushing in like normal, it has worked great for quite some time/miles by now.

 

I did a quick R&R of the front wishbone and replaced the large busing last night, relatively straight forward. Didn't have time to test drive but does feel a little firmer than before. In light of the generally good condition of the bushings so far (got closer look at swaybar bushings which look good) I am starting to lean towards a potential shock problem. Only way of validating will be switching the two front ones around.... oh joy!

 

Here is the latest - replaced all the suspension bushings. I opted to leave the swaybay bushings alone as they look perfectly fine. I switched the front air springs around... and the noise change sides. So, I now have fresh bushings on the front - that's good - and need a new front air springs - that's bad! Are all the US - XJ8 springs alike or is their a difference between the XJ8 and XJR?
THX
Franck

 

The air springs are of two types, (1) Comfort, and (2) Sport. Sport springs have a smaller diameter diaphram and give a harder ride, but shock is the same. Personally, I'd like to swap to Comfort, (my car is a Sport)), but the cost is too much. I bought car on its condition, which was and remains superb - 10 years old and 65k miles

Here's my fleet. BTW, the second pic is called "Dignity and Impudence" !

 

I am going to get a rebuild one from Arnott and stick with Sport. I know this may some bristle some folks but the air spring is really not a good set up for a car with power like the XJR, it's way too soft and under damped...fortunately my wife (her car) is reasonable and doesn't throw the car around too much.

 

Unfortunately the news isn't good. The noise is still very much on the driver side despite my initial (wishful) thinking that it had moved after switching the shocks. So, after replacing the upper a-arm and lower wishbone bushings I am no further ahead and gradually running out of ideas. The car has been on the lift, have removed the panels and checked over and nothing is obvious. The noise is noticeable even as walking speed and is present even going over the slightest little road imperfection....

 

When you mention you have changed the lower wishbone bushing would this also be the same as replacing the lower rear control arm bushing? Reason for my asking is I am in the process of having both left/front lower rear bushings replaced. I detected a slight noise, but only when at slow speeds next to a wall while braking or turning. I wonder if this is your problem as well.

Issue manifested itself when at slow speeds (3-5 mph) slamming the brakes would cause what I would best describe as a movement of something in the front end although there was no noise associated with movement. Car is in my indy shop now getting them replaced I suspect this will take care of the problem as the issues all add up.

Good news is the lower rear bushings only run $40 a piece plus labor to install.

 

If you've eliminated everything in the suspension, maybe subframe bushings? Fraser mentioned this as well. Would be the place to look if everything else checks out.

Where did you source rear lower control arm bushings?