I unfortunately didnt notice this when i test drove the car because we didnt get an opportunity to get to that speed. However my car has a very bad shake at 60+ mph. took it to a tire shop thinking maybe it need just needs balancing. did that, didnt fix the issue. They're now thinking i may need new axles (car only has 27k miles).

wanted to get your opinions, could the be the case? or could it be something worse (AWD system or something). there's no errors displaying on the dash.

 

Did you say that your car had sat for a year on the lot? If so, I would suspect that the wheel bearing have flat spots.

Just a thought,

wombat

 

i went to a tire shop today to check out the tire balancing. told them the car was on the lot and my concern about flat spotting. they checked it out and said everything was pretty normal.

what do you mean by wheel bearing flat spot?

one thing i didnt mention which might make sense now, at idle i can feel a high frequency vibration through the car, it goes up my seat and into my body. i wonder if its a drive shaft or prop shaft?

 

If you're thinking driveshaft/propshaft then a likely culprit is a/the "guibo".
Shouldn't be too hard to get underneath with a torch and have a look, I believe if a guibo is shot it's fairly obvious to spot.

 

Vibrations around 60mph usually sign a driveshaft balancing problem or worn giubo, as mentionner above. These are what I’d check first. One can check/balance a driveshaft without dismantling, check the DIY videos on YouTube..

 

IMHO, You should have the alignment checked for the above 60 vibration and the motor and transmission mounts changed as they can harden and and crack (then engine mounts are fluid filled).

 

Thanks guys. I have an appointment on Monday with the service center. The car came with a 60 day power train warranty that covers some of the items you listed. So hopefully that can get resolved. I should have pushed the tireshop a little more to check the drive shaft and under the car. it was a mavis tire shop, they're full service...but they were doing me a favor by dropping everything and looking at my car (versus making me wait). I feel like the mechanic that recommended that it was a drivetrain problem would have looked....maybe he wasnt comfortable

in the mean time, should I stay out of the car? Don’t drive it?

 

In the last thread on this subject, I suggested that you go to a shop with a Roadforce balancer. I did this for a reason, as it's the only way to eliminate the tires and wheels as the cause. An ordinary balancer will not do this.

If you think about it, a square wheel will balance perfectly, but won't give you a smooth ride. The Roadforce balancer measures the actual runout with a simulated load.

Did the Mavis shop use a Roadforce balancer? If not, you have not eliminated the tires / wheels as the cause, and you need to do that before looking at other possibilities (some of them pretty bizarre - flat spotted wheel bearings? LOL!)

The Roadforce balancer is just a tool though, and will give best results in the hands of a conscientious expert. Pick the shop with care.

 

i called mavis, i asked them about the roadforce balancer....they said yes it was roadforce, but i dunno how confident i feel in his answer. i will try another shop later this week. being christmas eve today and christmas tomorrow, shops are going to close up early.

 

If your XJ came with a 60-day powertrain warranty, then you should take it back to where you bought it. Don't tell them that you already took it to a tire shop or anyone else to have it checked, as that might void your warranty. Just tell them that there is a severe vibration over 60mph and let them figure out how to fix it. Don't say anything else.

Do you have that warranty in writing? Was the seller a Jaguar dealer or other used car dealer? Did you pay for a Pre-Purchase Inspection from a Jaguar dealer? Good luck, and I hope that you have a good experience with an honest and honorable dealer.

 

Wheel bearings, HIGHLY doubtful, but tires, most definitely so. Tires can balance out well, but still develop permanent "flat spots" after sitting that long.

 

i did not do a PPI, bought the car from a used car dealer, not jaguar. i do have an appointment on monday to bring it in...so we'll see what happens. but between now and monday, im going to try and find a tire shop that can do the roadforce balancing....i would hate to spend $1k on tires to find out it wasnt the tires

 

Just how far have you driven it over 60? If they’re well flat spotted, it might take 20 miles to work them out. The tires have to warm up, which might take ages at the current ambient temp. I’d make sure you’ve done this before any balancing.

did I mention I hate Pirelli A/S tires? My last XJR was a nightmare for flatspotting.

 

the ambient air here is cold, below 40....i drove from the dealership to my home, which is around 30 miles....mix of speeds from 45-70 (due to traffic)....drove the car on friday approx 40-50 miles...speeds ranging from 30-70 (due to traffic).....ive done a ton of local (under 50 mph) traffic...and it wasnt shakey

my concern about staying at over 60mph for a prolonged amount of time is that the shakes get so bad that i feel it through my body. the steering wheel doesnt shake so bad it shimmeys a bit, but the car sends shakes and vibrations through the seat that make my teeth chatter...which makes me feel like maybe its not the wheels, and if its something mechanical, i dont want to break anything. also, do i need to over-inflate my tires for this to work?

i found a tire place not too far from my house that has a road force balancing machine, i will go there in the morning, hopefully they will give me a final result. i would love to just swap rims with someone real quick and see if the issue stays.

 

I'll say it one more time, 4 Wheel alignment is critical on an XJ

 

update, appears to be roadforce issue. 3 out of 4 tires had 15lbs of roadforce, the 4th had 22lbs.

needless to say, i ordered a set of 4 Conti DWS06's.....had them on my XFR, thought they were pretty good tires. the shop recommended Mich AS3+, but i unfortunately only had 10 minutes to make a decision in order for tire rack to ship them out today.

hopefully this resolves everything (yes I will do alignment)

 

When I get tires my shop will use a balancer that measures road force and if a tire is over 15 LBs the deflate it, break the bead and rotate the tire on the wheel and inflate and test again. I would have recommended you do this before changing all tires and have your shop do this on your new tires, but that was your call. Also, I would choose Michelin's over any other tire manufacturer. IMHO. I still think your alignment is off.

 

the owner told me he tried to re-seat the tire but it came up bad again. i probably could have tried to find a way to pro-long the tires a bit longer....most of them were manufactured in 2015, one in 2017....so they're getting a bit worn. plus they were pirelli zero nero tires...and i had a really bad experience with them while trying to stop on a bit of snow....so it felt like a right opportunity to just get new tires and call it a day.

 

The re-seating process is called Ride Matching. It doesn't surpise me, one of my Pirellis also wouldn't come within spec with ride matching.

 

I'm no fan of Pirelli tires. I've suffered through them when they were on our new cars. My wife's Audi SQ5 came with P Zeros and the rode hard and wore fast. I replaced them with Michelin Pilot Sport 4Ss and it rides and handles so much better. Not to mention the extreme confidence you have in inclement weather.