Last December, for the first time ever, while in Ohio for the holidays I observed a clunking over ever single little bump both audible and physical (I could heard it loudly and feel it in the steering and gas/brake pedal) only for the first 20 minutes of driving from a cold start after sitting overnight, more so at low speed (under 25mph) but still pronounced up to 50 mph, primarily from the RH front though possibly the LH front but NEVER from the rear. After 20 minutes it would go away completely as if it never happened. It did this every single day. Front lower control arms had already been replaced by this time and air suspension was functioning properly. No one was able to come up with any suggestions and I ended up shrugging it off as something related to low temps (even though cold weather was no stranger to this car and this was the first time this issue appeared).

Anyhow, I just spent a few weeks up there again and amazingly enough, the exact same problem appeared with the exact same symptoms except now the weather has been 100+ degrees Fahrenheit. I am back in Florida and again unable to duplicate the problem.

Any suggestions for the Jag dealer service?

 

i get your frustration. i hate when things like this happen, it makes you over think the problem and you start to come up with all kinds of random "possibilities." the last couple times my other jag (a 98 vanden plas) developed a miss fire when in Louisiana. i cant source it to the gas because i was still on the same tank when i filled up in Houston. when i refilled the tank coming back it still misfired. when i got home and parked, the next morning I'm going to find out the problem but it never happened again. this happened at least 4 times. 3 service check ups with no answer. i haven't taken the car to Louisiana since and it has never misfired again. i come to the conclusion my car is alive with a personality and hates the cajun country!

 

The problem has persisted and gotten worse. Now it does it consistently every morning whether it is 80+ degrees or 30 degrees. Even the smallest bump makes it clunk until about 20 minutes have elapsed and then nothing will make it clunk

Air suspension has been replaced and suspension links have been replaced all with new parts to no avail.

The fact that it goes away consistently until the car has sat for a day makes me think it has to be related to the air suspension, but with new air shocks and a compressor that runs consistently raising the car up as soon as it is started every time seems to indicate all is functioning. The dealer has yet to find anything amiss.

Any thoughts?

 

Check out the brake pads. Had the same problem after a pad swap, clucking would go away once the brakes heated up.
The disks were worn but still in spec, in any case replaced the disks and pads, problem solved

Cheers
34by151

 

Pads and rotors are new, could it still be that? I can also feel it in the steering and floor board.

To me it feels like worn out shocks, just as an example. OF course it is not since they are new.

 

Check the sway bar bushings next, not the end links.

 

I agree it sounds like your air suspension.

 

That's what the dealer thought before they replaced the shocks. They said when the shocks don't completely inflate in cold weather, they will clunk for a while until they get fully charged.

So they replaced them and it no longer requires just cold weather, it does it all of the time, at least until I have driven for 20 minutes.

Could there be an issue with valve controller perhaps? There are no error codes, FWIW.

 

I do not know your situation but if you can get it on a lift that is what you want to do. Be sure your system is pumped up. Get it on the lift (one that lifts the car with the wheels not the frame) have a spray bottle of soapy water solution and spray the pressure lines first then work your way to the pump and the shocks. The controller needs to be checked along with the fittings. If you have an external leak you will find it if the leak is internal spraying it may not reveal the leak but give it a try. Take one step at a time and see what takes place.