My 2007 XK with 54K miles has a mild but bothersome vibration felt in the steering wheel and floor panels. I know about the vibration caused by the cat converters and the brackets that should be there. I do get the grown/vibration at 1350RPM as many of you do but I also get a vibration at 70MPH that trobs on and off. It goes away when I take a sweeping turn to the left but is there when I go straight or take a sweeping turn to the right. I have had the undercarrage checked for interference and all the wheels have been high speed balanced and it is still there. Any ideas?

 

I've moved your thread from XK8/XKR 1996 - 2006 section to XK/XKR section.

Graham

 

It has been my experience that most vibrations on and around the 70MPH mark are related to tire balancing.


Vince

 

Caperss.

You haven't given us much info to work with. For instance:

1. was the bal job of the "road force" type?

2. did they check for bent wheels? More common than you may think as our wheels are easily bent.

3.what's the general condition of your tires. Badly worn or chopped up tires can be beyond help.

4. have you inspected the suspension for worn or failed components?

One other thought. The man on the tire bal machine needs to know what he is doing. I have encountered the occasional operator who was better suited to be working in a car wash.

Do keep us posted. I know this sort of problem can be a PITA to sort.

 

The Tires are 6 months old Continentals with 4k miles on them. They were spin balanced by two different shops. I watched the second shop and I didnt see any wobble or runout as they were spun up. I'm pretty sure the wheels and tires are ok. I am not familiar with "road force balancing". I havent checked suspension parts yet. I was thinking maybe a trans mount going bad but was looking for other input from thr forum. I am dropping the car off again this Thursday.

 

Separate the vibration source by putting the motor in neutral next time it vibrates. If the vibration continues unabated, then examine tires and wheels. Try swapping wheels from side to side to see if the vibration is different.

If you think the vibration is caused by a motor source, then look under the car again, this time with bright lights and small mirrors - looking for any shiny metal which indicates a rub area. It may be an exhaust bracket which appears at first blush to be in good shape.

Next, I would check the motor mounts. I have never tried this on a Jaguar, but it has worked on other cars: I put a transmission jack under the motor and very gently pressed upwards. With good mounts the motor should restrain the jack pressure. With bad mounts, of course, the motor will lift with the jack pressure. You will not need to "lift" the motor much, say less than half and inch.

 

As I understand it, the only balance machine that does road force balance is the Hunter. There may be other "trade" names for the function but I've not heard it.

It wouldn't hurt to ask the tech/serv. writer to check for bent wheels just to get it on the record.

I don't know what it's like in your neighborhood but my tire dealer will stay on it till the tires are right at no addn'l charge - assuming no mechanical issues with the car.

 

Thanks to this forum I finally got my dealer and Jaguar North America to order a fix on my 07 Xk installing the cat conv brackets. The corperate office in N.J. is splitting the cost as a one time good will gesture. I still have the 70MPH vibration and the dealer wants to replace the driveshaft for $1300 bucks. I havent picked the car up yet (they have had it two weeks) I have a loaner so thats ok but the dealer doesnt really know why its vibrating and wants to start throwing parts at it till it goes away. (Bush league) I told them dont. Here is the thing and I told the dealer this too. It doesnt vibrate in a sweeping left hand turn. Now correct me if I am wrong, if the shaft is bowed or unballanced or if a bearing in the rear or ouput shaft is the cause wouldnt it always do it? My best guess is a dry rotted or bad center support bearing or a dry rotted trans mount. Does anyone want to take a guess? I have had the wheels and tires balanced by two shops and the wheels and tires are fine. Oh yes one last thing they said the trans is leaking from the sleeve where the wires go into the case another 1300 to fix that. I think I'm being scammed. Anyone?..........
p.s. I love this forum and all of you are great, if not for this forum I probably would have sold one of the best cars I ever drove and I am trying hard not to sell, this car is awsome I just want it to stop vibrating.

 

If the vibration stops when in a left hand turn, the problem is in the left rear wheel or bearings. In the left turn the force will be temporarily unloaded and the vibration will stop. As soon as the load comes back, the vibration continues.

If it's the driveshaft, (I suppose you mean propellor shaft) the vibration will remain because the rpm is unchanged.

If you have a propellor shaft vibration, it won't only be present at 70 mph, but also at around 35 (less) and around 105 mph. (worse)

It should be easy for the dealer to check the rear wheel bearings by disconnecting the connecting driveshaft and rotating the wheel.
Jaguar dealers also have the option to balance a propellor shaft while under the car. this will cost a lot less $$$.

Of course my answer is based on your diagnosis.

 

I agree with Dutch. Sounds like wheel bearings if it stops while turning or swerving but continues when going straight.

 

Thanks guys! Now that makes sense to me, it makes me wonder. Where are this dealers techs being trained or are they trained? This dealer works mostly on Land Rovers and it shows

 

Picked up the car today and the 1300RPM vibration is gone, it didnt move up the RPM scale like some others said it may. Its like a new car now and I am very happy with the results. The 70MPH vib is still there but even that feels less harsh but its still there. Time to start isolating wheels and I will be concentrating on the LH wheel bearing since in a left sweeping turn it goes away. Thanks again guys!

 

Been following your thread, as we sit with cars of the same year and relative mileage.

Personally, I'm not sold on the dealership replacing the drive shaft, but that said, I can't find any other 07 or newer on this forum needing a replacement wheel-bearing either. Not that it can't be... just that it is not a complaint I can find as a common point of failure.
Same goes for mounts. Having had cars (not Jags) from the southern desert areas like Salton Sea and Palm Springs, I have seen rubber fail prematurely thanks to the dry heat, but your far from that environment.

I'm still betting on tires or rims. I recommend you find a good performance shop and get them to do a once over. If your unsure who is "good", then visit your local track/road course during an SCCA event and you will find many car enthusiasts more that willing to point you in the right direction for your area.
Dealerships are fine, but I knowing suspension professionals that eat sleep and drink vehicle balance and control may be worth your time.

Vince

 

Salton Sea? They have cars there?

 

Sounds more like the OP's 07 XK has glazed-over brake pads. These will unevenly bind against the rotors, causing vibration at 70 mph. He mentions feeling the vibration through the steering wheel...not a driveshaft transmitting vibration, but either a bent wheel or out of balance tires, or glazed brake pads binding the rotors. Have a new tire balancing machine check for a bent wheel and balance the tires. Remove the pads and take a high speed sanding wheel to them, removing glaze. It'll take a few hundred miles for them to wear smooth.

 

She is going in the shop again to check for glazed or hanging pads and just clean all the sliding surfaces, Im also going to have them check the wheel bearings up front and recheck any wheel runout. I will keep you all posted.











i

 

I'd ask them to check the left rear wheel bearing....

 

I will Dutch, Thanks for reminding me....

 

ok just back from the shop. Here is what they found but I havent been able to test the car yet because it is snowing very bad in the Boston area and a 70 MPH run was out of the question for now. When they took the wheels off and pulled the calipers to check things out it was obvious that who ever replaced the brakes last failed to replace the rotors or (cut the rust edge off the outside of the disks. The pads were new but especially on the drivers side the rust ridge that forms on the outer edge of the rotors was rubbing against the pads and no doubt causing some of the vibration. I cant wait to take it up to speed to see if it is finally the cause of this irritating vibration. It just brings to mind what I learned long ago when learning electronics trouble shooting,KISS (keep it simple stupid) and this very well may be the case. I will let the forum know as soon as we get better weather...........

 

A vibration caused by brake pads...never heard of it btw....they are stationary...should be always present because the position remains unchanged all the time. You might only notice some difference when the brakes are applied very lightly.

A vibration caused by warped brake discs is possible, but at the rear this is hardly noticable At the front it will cause a shaking steering wheel, but only under braking