I just purchased a 2019 XJ L 5.0. with 41k miles.

Previous choice was the same but 2018 with 33k miles but 60 month warranty had expired. Beautiful car but first mile out of the dealer on a test drive it was obvious that there was a serious issue with the suspension and/or tires. Above 30 mph that was a dramatic wheel hop that could have been a flat spot on one or several tires. Best described as a 'hop'. Got worst at higher speed but strangely was not speed sensitive. Just got more pronounced. Discussed with salesman and manager and they acknowledged that was something wrong but they were of the opinion that they were not going to spend any more money on this car. CarFax history displayed 3 years of attempts to address this issue from initial sale.. Alignment and balance at 5k miles, balance and rotation at 6700 mi, sold as certified preowned vehicle a year later at 12,354 miles after tires balanced with 2 tires replaced. Tires dismounted and remounted ICW certification. Tires rotated at dealer after sale as Jaguar Certified vehicle.

Walked away and found the above described 2019 on-line with 11 months and 20k miles left on the warranty.

I purchased a CarFax report on this car indicated which indicated that wheels were repaired at 1150 miles and that 4 wheel alignment was preformed. Vehicle was sold at 5,826 miles. At 20,795 miles tires were balanced and aligned and rotated. At 32,294 miles a new tire was mounted and rotated . At 32,543 miles four tires were mounted, balanced and aligned. At 39,963 the car was sold again after auto auction at 40,177 and again to
me.

In my humble opinion after working on cars for 50+ years this is not a tire problem.

'Hop' starts below 50, and is not speed sensitive. Has been documented on two exactly similar cars. Multiple efforts to resolve with wheels, tires, alignments has been unsuccessful.

I am attempting to initiate a discussion with the service manager at the not-very-close Jaguar Dealer. The Forum's input would be appreciated.

 

I thought you began a post about this yesterday, but apparently it was a reply to some existing post.

Any chance of it being something like the drive shaft out of balance? Or maybe the bearing in the middle of the driveshaft being bad (I forget what it's called, something like a guibo or something).

 

I did. Replied to a similar post after a search. Didn't get a reply so thought I would start a new thread. Still no response.

 

Have the tires been road force balanced? This sometimes reveals different issues than a standard bench balance. Is the TPMS light on or is there a chance the TPMS sensor has become dislodged or broken off and is causing the tire to be out of balance?
Are the brake rotors in serviceable condition with no mud or debris stuck in the gas vents? Anything in the driveline that rotates can cause this problem; expect the unexpected. How is the condition of your rear CV boots?

I wouldn't describe the main symptom of a bad driveshaft center support bearing as "wheel hop"... bad CSB symptoms include vibration that doesn't seem to come from any particular corner of the car. This can sometimes lessen at speed as it matches the resonant frequency of the vehicle and throws people off the diagnostic trail.

If I lift the rear of the car, remove the wheels and rotors, place it in drive and run the rear axles up to speed (SAFELY, TCS off), what happens? I had a similar issue with a truck I owned. Wheels and tires were balanced but the vehicle would still shake terribly on the highway, but would lessen the faster I went. It was maddening. Turns out that the driveshaft had thrown off one of its balance weights. I wouldn't expect this at less than 50K miles.

How are the condition of the shocks, strut mounts and control arm bushings? A bad shock can easily cause wheel hop.

 

Good point, but I can't think of anything other than really bad shock absorber(s), really weak or no spring(s) (not likely at all).

 

I replied your earlier post, please check my thoughts there, but it think this is the key: "wheels were repaired at 1150 miles"
The wheels aren´t propably round anymore on area where tyre is sitting and no balancing or tyre rotate can´t fix that.
Try complete wheel/tyre set from another jag what are known not have an issue.

 

The thing that puzzles me is that the frequency of the 'hop' is not subject to engine or vehicle speed. The only thing that changes is that the vibration increases in vibration and consequently, the sound volume with speed. Just doesn't seem like a rotating part issue.

I will go out at lunch to see if I can describe the issue better.

 

So it only increases in amplitude and not frequency?

 

Yes, that defines the issue.

Spent some time this afternoon trying to better define the issue. While I have felt the 'hop' at 30 mph costing down in speed, it is much more pronounced at 50 to 70. Traffic does make higher speeds reasonable. I will try again early tomorrow. I just do not feel any change in frequency of the vibration only the increase in the seat, not the steering wheel.

It is much more pronounced vibration than my 2017 Explorer with 80k miles and Michelin tires with 5k miles on them.

 

This sounds more like a suspension problem and not a driveline problem.