I'll probably get new tires in the summer, but a separated belt doesn't really explain why it happens only when the gas tank is more than 1/3 full. I guess your car isn't making this sound?

 

I do not have this problem. I have the Pirelli P6 tires (very noisy). No bump or thump sounds. I did have my brake discs and pads(ceramic) replaced because of a high pitched squeal.

 

I have the "sloshing sound" problem. '04 XJ8 w/94K miles. Been happening for a while. I only really notice it when easing into the garage. There's a slight lip from the driveway to the garage floor, and that seems to set it off. I've always assumed it was gas slosh.

My car is at the dealer's right now getting new bushing on all four corners. Thankfully, I was talked into buying an extended warranty for the car when I bought it, something I don't usually do. So, $3K worth of work will cost me $200. If the problem is indeed a loose bolt on the shock, as someone else mentioned here, it will hopefully be found and fixed with the rest.

BTW, I have Michelin MX4(?) tires, all-season. Came with the car. Don't like them, I think they are too noisy. They are at the outside edge of needing replaced. I plan on getting Pirelli P6 when the time comes.

 

Let us know if this fixes the sloshing sound!

 

...and I love how my XJ don't cause any problems any more, and it now has 87k miles on it LOL, in fact for some reason it feels more fast now, like it revs faster, I don't know if it is the cold air intake I got but yeah feels pretty quick now

 

Hi, Alan, not sure if you were directing this to me, but I did "fix" my problem, in an extreme way: I traded my XJ8 for a 2010 XF!

The cost of repairs almost equaled the Kelly Blue Book value of the car, so I had a talk with a salesman and got a good trade-up deal for the XF, which had been a rental. Only had 16,500 miles.

 

Dang. Congratulations!

 

the steering pump squeaks got all my attention...lol.

I thought it was something in the trunk, or the spare being loose, it is really only noticeable at low speed stops; after having the car checked out and being given a clean bill it really only leaves the fuel tank as the culprit;I didn't see much diff in the noise with the level of gas; just might be a wall of the tank flexing or bottoming against a mount or bulkhead.

 

No, its not tires. Only time the noise surfaces at slow speed pulling into a garage, normal street driving you don't hear it. My 04 XJ8 and my 06 XJR produce the same noise. Its definitely no big thing, just something to bitch about.

 

I think people who say they don't have the noise just aren't that observant. It's a design characteristic, they all do it!

 

I believe the issue you are having is caused to a harsh 2-1 downshift. Jaguar does have a tcm reflash to fix this problem. hope this helps you the next time you decide to take your vehicle in for work.

 

But it can happen in neutral!