I am having trouble locating the source of a low knocking noise from somewhere forward of the passenger compartment. It only occurs on unmetalled roads or some tarmacked roads with an uneven surface and then when the car has not been used for a while. For example the first time in any day and then only for about 3 miles or so after which time it disappears. The mechanic who does the jobs requiring a professional hand has said it sounds like the suspension bottom ball joints, but there is absolutely no play in them in any direction when using a pry bar. I have checked myself. On looking at previous threads I see that the most likely is the bush on the lower control arm where it's connected to the body but using a pry bar I can find only a limited amount (1 or 2mm) of lateral movement (along the axis of the fixing bolt) and none fore and aft. There is no sign of liquid having leaked from this bush. Is this amount of movement normal or unacceptable? Incidentally the car passed its annual roadworthyness (is there such a word?) test a couple of months ago with no comment when this noise was manifesting itself. I emphasise that it goes away after a few miles driving and had stopped by the time I arrived at the testing station.
Any ideas on what to check? Respondents on this forum seem so much more knowledgeable than I and I haven't found any independent jaguar experts locally, so it's down to me with the help of you guys. I look forward to your comments.
.

 

From 60 years of driving cars and trying to understand their workings and repair, on a virgin suspension I would start with the stabilizer link, as the most likely to fail.

 

Thank you for your suggestion but I have just done that about a month ago. No change unfortunately. Thanks for the thought though.
I have also changed the top wishbone and ball joint, both sides.

 

The noise may be from the steering. Check outer tie rod ends, by raising the wheel off the ground and with your hands at 9 and 3 o'clock, push and pull the tire for a degree of looseness. The inner tie rod, wears out less often.
Top ball joints tend to last longer than the bottom. They work less.

 

Oh dear, I must be getting old and am certainly forgetful these days. I should have mentioned that I had done that and changed the track rod ends. Sorry to put you to the trouble. I'm running out of ideas on the suspension unless it has something to do with the shock absorbers. On another track could it be connected with the exhaust as it stops when warmed up?

 

Did you check the isolators and top mounts for the shocks? Very common for them to fail.

 

The banana arm as the front control arm is referred to is a bear to test until it's completely shot. I had mine diagnosed by going to a tire shop. They put the car up o a ramp so I could see the movement in both the wheel and the arm bushing. The mechanic drove forward a foot on the ramp and hit the brake hard. I should see the bush move, even though I couldn't replicate it with a bar. Also the wheel moved almost like the caster changed then changed back. I'm explaining this poorly I'm sure. I checked the stabilizer bushes by disconnecting the links from the wheel, tyed them off and drove the car. If the bushes are a problem, the noise will stop. Of course this was local street test driving only.

 

My 2008 xk has worn out shocks. In warm weather the rattle/clank/choose a phrase makes noise for 3~5 miles then it is near totally gone (not really but one must listen very carefully). In cold weather they do the same for 5~7 miles and then the noise continues to lessen until gone.
I believe there is so much additional clearance due to wear (the rattle/noise) that it takes those miles and associated shock movement to expand the inner pieces enough to reduce the noise. Or maybe get the fluids where they need to be in order to do their job properly.
as an aside I had a 1997 Taurus sho with semi active ( 2 stage) shocks...same issue, started making noise @ 100k miles...when I replaced them the noise was gone.
wj

 

Thank you everyone. Food for thought and examination. Back to the mechanic.
Cheers,

 

The mechanic who does the more difficult jobs on my XK had a ride in the car some weeks ago and thought it was the bottom balljoint in the vertical link and after a few false starts the joints were changed on both sides last week. According to him the LHS ball was really loose in the socket despite showing no signs of movement when on the ramp. On road test the knocking had stopped. Hooray!
I took advantage of the disassembly to have the large bush on the lower control arm changed but now it seems that the smaller bush will also need attention soon. As this is not a serviced part it means complete control arms (pt no C2P17091) unfortunately, so a waste of money on the bushes. Still Lemforder control arms (pt no 42283) are available for about €150 each rather than about €650 from Jaguar so this will probably be next month's job.
Thanks to all who provided input.
Mike

 

Hello everyone. I finally solved the mystery issue with my front suspension thanks to a forum member on this thread. I had replaced all control arms, sway bar links, ball joints on the front with brand new parts, however I still had a wobble and clunk when I was driving at slow speed over bumps. I reached out to many suspension shops and they all were not able to figure out why with all parts replaced I was still experiencing that. Some even suggested that my coils shocks were the problem but I had replaced them 15K miles ago with brand new Arnott's. Finally a member suggested to me that I look into the Sway Bar Bushings but to my appearance and to everyone else that looked at the car they looked in good and new condition. After much consideration I did take this members advise and followed his instructions and to my surprise the results were the Sway Bar Bushings. I immediately changed them and upon doing that I came to learn that all the worm rubber was from the inside part and not the outside. I recommend to everyone who has experienced this issue of wobble and clunk over bump at low speed first to change the sway bar bushings before looking into anything else unless there are visible signs of wear and tear.

This was a very frustrating and costly experience but lesson learned that $25 in part no. XR819697 and 3.8 hours of shop time (Does not include alignment) would have saved me plenty of money. The good of all this now I have an entire new front suspension.

Also note that if you are going to do Ball joints the shop time is 3.4 hours which includes control arms something I did not know and was taken advantage of that by a local Jaguar specialist. I learned that after the fact through the journey of finding the clunk.

Hope my bad experience will help other Jaguar owners to not fall in the traps that I did.


Respectfully,

Mike K.

 

Sailor Mike I suggest you look at getting parts from the "Rock" company in the USA, and stop changing bushings. I had a car that needed stabilizer links every 60,000 Kms. You called them control arms, which is a bit too generic and threw me off, because there are so many suspension parts on the Jags.

 

Sony 2000

I buy Lemforder brand for all my suspension parts which are much better than what "Rock" company carries in my opinion if it's available in that brand. This was the first time I changed the bushings on the car since I had it in the last five years and the car now had 115K. In USA that is how they are referred in auto lingo. Actually the suspension parts all together at the front are about 12 to 13 pieces in total if I recall correctly. Anyhow go Lemforder if it's available nothing like German quality. Cheers.

 

Come August it is easy to be received at my independent garage, and there I try to do repairs on my daily drivers that will take me thru the winters without repairs or servicing. My 2007 needed the left front tie rod end. I had it already from the "Rock" closeout at $3.00 USD. Two boots from Bulgaria were needed and installed. That long horizontal rod on the rear had already been bought for about $26 USD. The outside boots were very chewed up. The rear breaks were 80% good, but one was at 25%. So I will have one pad changed, clean the slider pins and hope that will improve the rate of usage usage.

 

Sony 2000, Getting anything from outside the EU is a nightmare if you live in Spain. Apart from delays in customs, there's the problem of providing a delivery address to a transport company who doesn't deliver to a countryside address like mine, providing an original government certified idenitity document, payment of import duties and taxes in advance of delivery etc. etc. Only things costing under about €15 will get through unscathed. The knocking problem is not yet solved despite my optimism in my last post. Anyway now I have all the (Lemforder) parts to replace nearly all the remaining front and rear suspension components and just have to wait until I can summon the energy to do the jobs involved. I'll probably wait until the weather cools down too. Further updates when the job's done.