Hi there!
I have an 04 X350 (XJ6). At various cruising speeds, 30mph = quiet,but still there to 70mph = annoying, although not loud enough for a non-regular passenger to appreciate that its a bad noise

Not only when power is applied but also when decellerating down a motorway exit slip at around 40mph without brakes applied, this gets slightly louder again.

The resonating sound is quite comparable to wheel bearing noises of older cars I owned as a youngster. Dealer has said bearings are fine though. Tyres were replaced 3000 miles ago when the last two fronts became mis-shaped(Pirelli says not manufacturing fault?) and also made a noise comparable, but much louder than this. They have since been rebalanced which didnt help.

Car has recently had new Air Suspension ECU and Compressor (>GBP£1000 worth!) 19" oem wheels fitted with Pirelli jaguar spec tyres.

Any ideas?

 

HBZ, a quick check that you can do is get the car up to say 60 mph and then take a sweeping turn at speed (doesn't need to be really sharp, but more like a curve in a highway). Do this for both directions (left and right). Does the noise change any? If yes and only in 1 direction, then the bearing on the side that you are turning towards is probably bad (flat spot on one of the bearings due to hitting a pothole possibly?). I have a problem like this periodically with my truck.

After that, try rotating the tires around and seeing if that causes the noise to change. if yes, then you have a tire issue.

Much beyond this, I would need to hear the sound to give a better diagnosis.

 

Hi there, thanks for the advice,

I've tried this 6mph turn with no change in noise. After much Google-ing, I found one or two people mention that the Pirelli's do sometime cause extra noise and have seen that it may be reasonably common for them to grow a "bulge" like my old front set..

I cant really afford to replace the tyres yet again, so I think I'll try rotating the wheels and see what happens to the noise.

I'll get back with an updat once the snow clears a bit!

Thanks again

 

I have the Pirelli P6's on my XJ and they are getting louder every day. They are driving me crazy. I'm going to try the Riken Raptor AS tires this Spring. I have the Riken Raptor performance tires on my XKR and they are great AND quiet.