I've started to notice a low rumbling sound that seems to be coming from the rear of my XJR. It seems to start after 20 minutes of city driving and is most prominent at acceleration and when turning.

Wheel bearing? Rear diff? Exhaust system loose? Bad gas?!

Seriously any ideas before I get a change to get under it?

 

Wheel bearing problems are not unusual on X300s. Nor are diff problems, for that matter....but not as common as wheel bearings.

You may have to get the rear wheels off the ground and listen for the noise with a helper working the throttle. Be careful!

However.....

In the last year or so the exhuast has become louder on my XJR. No holes anywhere.....it simply has a rumble that wasn't there before. Not obnoxiously loud, but it's there


Cheers
DD

 

While you have the rear wheels up in the air trying rocking them with your hands at 12 o'clock and 6 o'clock.

Anything more than a mere fraction of movement and the possibility of rear wheel bearings becomes stronger

Cheers
DD

 

Agree with Doug.

Mine developed that similar described rumble, and also only after 15-20 minutes driving.

It is not an "R", just a lowly 3.2 XJ6.

Turned out to be tyres. Furthest thought at any time, but some new rubber, SILENT.

I went thru centre bearing, wheel bearings, exhaust etc, and finally some wheels from a mates XJ8, just for giggles, found ya.

Doug, my 3 Jags have that exhaust "drone" sound, that was not there when we first got them. My "scientific" evaluation is that we drive these cars MUCH harder than the previous owners, so all that gunk in the exhaust etc has been blasted out, and the Jag rumble is what is left.

My Black S Type has started the same rumble, and worn Pirelli's are my first thought.

 

I failed to mention, the car has new tires so hopefully I can rule that out. I do have a slight exhaust leak at the manifold, but that's quite a different sound...at least at idle. Thanks for all the tips, I will check wheels and do some more investigation.