Not sure if it's the traction control working or if there is a problem, but occasionally when I make a slow, sharp turn after not driving very far from a cold start, I will hear a groaning noise (sounds like it could be the brake) for a very short period. I know my Infiniti does that and it's a brake check. Going in tomorrow and want to make sure I get them to fix it when my dash is replaced, if indeed it is a problem. Also thought it could be the differential if the inside wheel was trying to turn faster than the outside wheel. Any suggestions would be greatly appreciated.

 

CV joints are sometimes the culprit for noise during turning. I'd make sure the front CV boots are still in good shape and aren't leaking any grease.

The brakes could be the issue. Try tapping the brakes and see if the sound changes or goes away. If it does then it's the bakes.

The trans/diff could be the cause when the fluid is cold. It's hard to say. Hopefully the dealer can hear the noise.

 

Do you feel any vibration through the steering wheel when it happens? I had a similar-sounding issue last winter. It turned out that my power-steering pump had developed a leak and the fluid was too low when it was very cold, making the pump / system give off a grinding noise. Pump replaced on warranty and all is fine now. If you are feeling via steering wheel, suggest you check the power steering fluid reservoir to see if it's too low.

 

Funny, because I just filled the power steering fluid last week and it was quite low. And I don't think it's done it since. But the noise was definitely behind me so I doubt that was the cause.

 

Also wanted to add that it sounds like it's coming from the rear axle area and is definitely behind me.

 

Then I don't think it's the power steering issue - as the noise from that was clearly at the front of the vehicle - and felt through the steering column. Although you should monitor it given you just had to top up the fluid - and perhaps ask the dealer to check for signs of leaking on the PS hoses or the pump itself (should be pretty easy to spot).

Could also be the parking brake - they can seize up if not used regularly although not sure why that should happen when cornering.

Let us know what you find out.

 

UPDATE: Took it into the dealer for my dash replacement. They said the noise I was hearing was normal and that it was the differential working to take away the power from the inside wheel, which made sense to me. Wish it wasn't so noisy though.

 

Just saw this and wanted to share my experience today. It sounds pretty similar to what you were noticing, you may want to consider getting a second opinion:

I brought my car in to the dealership today to have them go over the car and to meet the mechanic / service tech that I would be cashburning with over the next few years. That relationship stuff from my experience goes a long way when you have things come up with your car. I wanted to just get an overall feel for where the car was at and what I may need to watch for despite it being in excellent shape.

They mentioned that the car was one of the cleanest, most well kept 2010 XFs they had ever seen. I did bring up that I noticed a very faint shudder and groan that felt like it was coming from the diff / rear axle area, only when I was stopped and then accelerating lightly into a turn. Driving straight you did not feel it.

It turns out that the differential is toast, they are replacing it under warranty. Like you I had assumed that it was just the trac system being a little overzealous with 460 torques but you know what they say about assuming. So I talked up the mechanic, he test drove it and told me that the clutch packs in the active diff lock up when accelerating straight and are supposed to release during turns. Some of the early ones never released though and this is one of them. It was so light and almost unnoticeable that it was likely the previous owner and mechanics in the past never caught it. So the good news is that I am super happy I have the select extended warranty (for stuff like this) because parts alone are about $3500. It also wasn't my fault so I feel good about that :P

On a side note I found that the previous owner had installed K&N filters which from my research here I wasn't crazy about and the tech confirmed that it is not a great idea to use these. So I have two XF K&N filters if anyone is interested ha

Anyway it sounds like we may have had similar issues so you may want to mention this to them or take it to another dealer to have them look at it. Hope that helps!

 

Kayanite asked me for it but I will go ahead and post it up here in case anyone runs into the same issue in the future. The differential was replaced under warranty due to similar behavior, here is the service tech's notes and part numbers that were replaced:



Hopefully that helps anyone who might run into the same thing. The tech said he has seen it on a few of the cars that have come in. I can tell you after the replacement the car is a completely different animal. All is well again

 

From your description this sounds like rear brake vibration caused by the traction control engaging at low speeds but high differential speed difference. You are correct that the brake us being applied to the outside wheel because the DSC detects excessive wheel speed difference left to right and tries to brake the faster wheel.

This is a software issue and probably cannot be engineered out without other negatives.

The XFR does have a mechanical LSD which could be the source. If som then the noise would found like it came from the center rear of the car. I think the electronics backs off the LSD for tight low speed corners.

 

Technically, the LSD brakes the outside wheel. Only a Torsen can move torque across the differential and Jaguar doesn't fit a Torsen.

Both types permit engine torque to be delivered to the slower turning wheel (inside wheel in a turn) but the type used in the XFR does so by absorbing torque from the faster turning wheel, the slower turning wheel is not affected but the engine can deliver additional torque to that inside wheel without wasting it spinning up the outside wheel. Engine torque is still wasted in friction in the diff. In a Torsen the faster turning wheel transfers excess torque across the diff and actually accelerates the slower turning wheel. Very little engine torque is wasted into heat in the Torsen diff.

This difference is significant and important.

Mechanical clutch tyoe LSD absorb and waste engine torque as heat in the diff. Torsen do not significantly waste engine torque.

Neither type takes away power from the inside wheel, that's just backwards.

 

So my rear diff is shuddering again. Have an appointment on Monday to take it back in so I will post an update. Im not sure why it is having this issue, perhaps it was replaced with another older inherently faulty unit.

 

Any updates? Mine does this on occasion and was told it's normal and they could not duplicate. On another note just had mine serviced and low brake pad light on. Going back today. Dealer said they were in yellow range. Already had front pads/rotors changed around 15k, not sure if this will be both or just rear. 27k on it now. 2011 xfr. Guess it likes eating brakes!

 

Yes the dealer told me that the diff checked out fine and that all four tires were cupped? That didn't seem right so I got a second opinion. A dedicated tire shop told me the front tires were fine but the rear tires were down near their wear bars and had slight cupping. That might make sense; the vibrations seem to go away once the car and tires warm up so it could be related to the traction control? I'm not sure, but the tires need to be replaced anyway. Once that gets done I will try to remember to report back to see if that fixed the issue.

 

Mine only seemed to do it at a stop sign and turning. Turning right was worse. This was after ten minutes of driving so I'm sure it was warmed up. Haven't noticed it much since it's warm or maybe I don't pay it no mind anymore lol. I just had my aligned. Noticed the toe was off on front, dealer said front and rear. $170 bucks...that was quite a shock. Tires were fine when I did hear the noise tho.

 

The good thing is if it's your diff and it's going out, eventually an error code will be tripped and they will have to replace it. Not sure of your warranty status though. Make sure they note your history just to make sure you can make a claim later if the factory warranty is still valid.

And from what I understand, you will go through rear pads faster than fronts. My rear warning has been coming on from time to time and I'm waiting until it stays on to switch to ceramics.

 

I've complained a few times but they never duplicate of course. Can't get mad, I'm a diesel mech and have that problem all the time so I know what it's like. Mine is a 2011 so everything is under warranty...brakes and oil changes included til 50k.

Mine just says brakes low, doesn't specify front or rear. Where are you getting your pads from? I assume what it came with is not ceramic?

 

I know that my rears have less pad thickness than my fronts so that's how I know.

The stock brakes are semi-metallic. They make far too much dust for me to deal with long term having chrome rims.

 

It was my rear. They said the sensor had backed out some but they were changing the pad and rotors anyway.

 

As WRX... has pointed out it points towards rear diff.
It's very similar to a problem I've experienced.
The noise was apparent when taking low speed sharp turns.
Jaguar said it was 'normal' but after a while (month or so) it eventually threw an 'E-Diff' code on the dash.
Turns out it was the motor that drives the clutch plates in and out on the rear diff needed replacing.

And losing power steering fluid is quite common, one of the hoses starts to weep.
Another issue Jaguar finally diagnosed ad covered under warranty.

HTH somewhat.

Andy