I just recently purchased a near mint 98 XJ8L with 96K miles that has a vibration above 50 mph but minimizes at 70+. It's seems to be coming from the front left but sends a low-toned vibration throughout the car.

I took it to a so-called Jag specialist who had my car all day only to tell me that I need a left tie rod because the boot was broken, front shocks that have worn lower bushings and have moisture around them, front brake pads and rotors, but could not tell me why, two front tires that were manufactured in the 33rd week of 2011 and look brand new. It has been two weeks and I am still waiting for an estimate.

In the meantime, I have had the tires (BF Goodrich Advantage T/A)rotated and road force balanced, a new left tie rod and four wheel alignment. Before the tires were rotated, the front left has worn unevenly on the inside, possibly due to the shocks. I still have the vibration. There does not appear to be play in the front bearings nor are they making any noise that I can detect. I do have what appears to be excessive tire noise when braking. It could be the tires if they car had been sitting for a while, but the tire guys said the road force balancer would have detected if the tires were out of round. They do appear to ride hard but that could be due to the shocks that I will replace tomorrow. So far, I have been to two tire shops, for two different balances, one rotation, an alignment and tie rod, a jag specialist who told me a hog pog of things, but the car still vibrates. I am wondering if it could be the rotors, bearings, tires, shocks, etc. I ordered new rotors and pads but will put them on after the shocks.

Do anyone have a clue? I am wondering if the tires got hard from non-use?

 

Do you have 16" wheels or something larger?

18"+ wheels get bent very easily.

Unless they dismounted the tires and ran the wheels alone on the Hunter machine, it still might pass as OK with a slightly bent wheel. There is a range for "out of roundness," the Hunter will only flag it if it is outside the acceptable range.

Another member had an out of balance rotor causing a similar vibration.

Or it could be severe flat spotting of the tires from sitting for a long time.

I'm betting its a wheel, tire or rotor.
Vector

 

Yes, I saw those posts. My front rotors seem to be slightly warped when I spin the tires. They hit a warped spot on one point of the rotor on both sides, but really don't pulsate when braking. I hear a noise though when braking and don't know if it the tires or the warped spot on the rotor.

I am going to put front shocks on, then new front rotors and pads, hopefully this weekend. If that does not do it, I will have the wheels checked on the Hunter.

Thanks again and have a nice holiday!

 

Sounds like you did/do have an issue with the front left wheel/brakes/suspension, but when you do all you are going to do, if you still have the vibration, it might be appropriate to look at the flex coupling discs on the propeller shaft. You may have two issues. The good news is that replacing those discs is straightforward and reasonably cheap.

 

When I first bought my car, I had a vibration. I would balance it and it was fine for a few minutes, then it would come back. I'd balance again, and it would come back. Sometimes an hour or so later.

I made the Tire shop remove the tire that kept going out of balance. They found Tire Sealant Goop inside the tire. Also, it was full of rubber CHUNKS due to being run flat for a long period of time (Sidewalls were gone inside). Cleaned it all out (About 3 Cups of junk!) and balancing was fine after that. The goop would stick to one side, then when warmed up would move around. Of course, I replaced the tires a few days later.

Just another thing to check...

 

Do you think it makes sense to check those before the tires? On the tires, I see visible flat spots when spinning the front tires by hand. Could the visible flat spot be causing the vibration? I don't want to waste money on tires if it happens to be the couplings.

 

Thanks for the input. That XJR is nice! Black is my favorite color. See my reply to JohnLeavitt.

 

I have a brake pad question. I see that some of the replacement brake pads for the front have 3 equally-sized prongs and others for the same car have 2 equally-sized prongs and one long prong at the top. I have not taken mine off yet but I bought the Akebono pads that have the 3 same-sized prongs. Any input on that? I would hate to tear the car down only to find out I should have the other pad style. And then, it could be the wrong ones that have been put on when they were replaced with the previous owner.

 

With visiible flat spots, the tires are toast as far as balancing goes. No amount of balancing can compensate for actual flat spots.

However, you may want to check to see if the flat spots are still there after a good warmup.

What brand and size of tires? Some will flat spot when cold but are fine after warmup.

 

I know tires are expensive, but does a man ever feel any more virile than when he drives away from the tire store with four new tires and stems? That's a feeling that I like.

On a serious note, tires are the biggest equipment related issue leading to fatalities in automobiles. I trade mine out at five years, whether or not they are worn out. They are something you don't want to scrimp on. Buy some good ones, and feel good about it.

 

I put my new KYB front shocks on yesterday and the car rode must better. In fact the vibration now is only felt at a higher speed (65-70) probably because the new shocks are masking the real problem better than the old ones.

When the car was jacked up, I did not notice the flat spots. The tires are only a year and a half old from the manufacture date code of 3311. The brand is BF Goodrich Advantage T/A 225/60 16 97V. I have read several reviews where consumers said they could not get this tire to balance. They probably have uneven were from the bad shocks but those fronts are now on the rear. I plan to replace them with Michelin Pilot Sport A/S Plus 225/60 ZR16 98W. I hope this will solve the problem. I am going to hold off on replacing the pads and rotors until the tires are replaced.

Thanks for you input. I'll keep you posted.

 

I agree. I'll get those new tires on this week. Have a great holiday!

 

Did the Vibration follow the Tires? Or were all 4 vibrating?

 

Great tire, I have them on a sl600. Very expensive. I can't complain, though, they are great.

 

It did not appear that the vibration followed the rotation. That is what is so puzzling. Because as you know, when you have a one bad tire, and it is moved, you can isolate the problem, if it is tire related. I have even put the spare (which did not appear to have been balanced since there were no weights on it) on one location, which out any real change. I'm going to get it balanced and then move it around.

 

I went to Mr Tire today to get my Michelin's installed. After having an extensive conversation with the tech before working on my car, I told him to check the drive line. He took the car out for a test drive first and then brought it back to the shop and told me that he would love to sell me a set of tires but said my problem with the vibration is due to some play in the drive shaft center support. He showed me on the car that he the drive shaft had excessive movement at the center support. He said he would check tomorrow to see how much it would cost to replace it. We also noticed that the car had a recently replaced drive shaft since it did not have any rust or dirt on it, but it looked like the center support and carrier bearing was older.

My question is is the drive shaft not supposed to have any movement at the point or is it supposed to not be able to show any movement. The was no movement in the bearing, just in the rubber surrounding it.

From my research, it appears that the center support and bearing is not sold separately for this year and you have to purchase an entire 2 piece shaft complete with center bearing and support. Someone else on this site said you can order the previous year, like '97 support and bearing and install it on the '98 shaft. Is that true. Before I go ahead and replace the shaft or bearing and support, I need to take it to my Jaguar specialist for confirmation about it you are supposed to be able to move the shaft at the bearing support.

I'll keep you posted. This is driving me crazy.

 

So there is some play at the center support. I bought a used drive shaft with the support from car-part.com for 200 delivered. I dont think you can buy the separately.

 

If the support you talk about is the differential, you need the output shaft bearing, JLM20337 , the cost is a very important one, around 250$ or more. It's a common issue on the XJ8, if the play is more than 0,15 mm the bearing must be changed (I have 6-7 mm and same vibrations).

 

I tried to post a pic of the joint....but my skills are not up to the forum par. I will note that you could just get the bearing up to the u joint, but then you would want a new u joint...etc. I would buy the whole thing.

 

Well I went to a so-called Jaguar specialist and he suggested replacing the flex coupling disc in the front. I had that done and no change. Went to Mr Tire today and they lifted the rear wheels off the ground and ran it up to 60 mph and felt the vibration but could not isolate it. They did not think it was the tire but I had the new Michelins put on anyway to eliminate the tires and although the ride improved the vibration is still here.

Well off I go to a reputable Jaguar Dealership sometime soon.