So I just got a 2004 XJR and I've noticed when I'm going up the hill to my house that at about 2000 rpm going say 25mph ish there is a whomp noise which I think happens when I lift off the gas. Any ideas what it could be.

Also for full disclosure the day after I got it (last Saturday) I hit the mother of all potholes on the freeway destroying my rim and tire so I'm running on the donut till they can get a replacement (it's a coventry hornet wheel)

Anyway any ideas?

 

Maybe the noise is related to the leveling system of the car. The donut probably makes the position of the suspension out of line, so maybe the car is adjusting? Not sure, you probably won't be able to really diagnose until you get your new wheel on it. Just a thought, good luck.

 

I have a similar issue, my xjr makes a noise like a BEEP or a whomp, when I get on the gas. Would be interested to know what this noise is also..

 

fila, is it a whoop noise when the transmission shifts?

brdave

 

mine happens more often when I get on the gas from a cruising speed.

 

Yes it's a whomp noise when it shifts - I kept it in second going up the hill and didn't hear it. Know what that is?

 

whomp/whoop noise that is

 

It is the transmission. I believe the XJ shares the same trans as the XK and this topic was discussed on the 1997 on xk page here. It will as well make the whoop noise on level ground under moderately hard acceleration when shifting. If your car is under warranty get it in and document the problem asap. There are tsb on the topic at the dealer. They will do a trans fluid flush with a special secret additive. If the additive does not fix it, things can get expensive fast.

Good Luck
brdave

 

No warranty - will only the dealer have access to the additive? Which fluid is recommended (Mobil 1?) and where is the best spot to get it?

 

dpenny, I have seen lots on this in the 1997 onwards xk section of this forum. I am not a technician but had this problem and went through the whole process with the dealer as well as read as much as I could on this forum when I owned my 04 xkr. I have since disposed of that car, the repairs almost killed me. Search whoop/transmission additive etc. in that section and good luck. I believe it is the same trans as in some german cars. Sorry I don't have the answers, hopefully someone else will chime in here. good luck
brdave

 

Almost all of these cars have the noise. Jag sells an additive that might fix it. As far as I know it has no negative effect on the transmission. It's just something you might have to deal with.

 

Drew that's my kind of answer I tried coming up the hill in sport mode and no whomp/whoop noise so I'll just do that and if I hear it more often I'll go the additive/flush route (which I will prob do in the next 10k miles at some point anyway as I have 50k miles on it)

Unless someone else thinks that the noise is indicative of the transmission being in desperate need of the flush asap lest it destroy itself.

 

My mechanic stated almost all the cars he has worked on had the noise. I didn't even know until he pointed it out to me on mine. One of the characteristics of this car.

 

I would have it attended to.

dave

 

So had the transmission drained and flushed by the great guys at XYZ Motors in Oakland and the noise is no more so I'm glad I had it done

 

Glad to hear that. That issue is not something to be ignored. Did they use the additive? Just curious.

brdave

 

No additive, just the fluid.