My XJ had a pretty uncomfortable ride a couple years back. Replaced bushings and control arms, much better. Switching from 20” to 19” rims and Michelins PS4 helped even more. Last thing for me to do is shocks/ struts, but not in a rush as ride is already way smoother than my new Tesla. Though I will do this too eventually. Best of luck!

 

i fixed the suspension, lower front control and bushes, rear lower control arms were also replaced, i am still not satisfied with the ride. the tyre pressure is at 30psi. i know i don't have the highest quality tyres, but i dont think the tyres can make a ride that bad.

 

.

 

hey, i replaced lower front control arms and bushes, and rear lower control arms. one of the front shocks was replaced a while ago and the other one my mechanic said it is good and no need to replace it

 

Tires do make a difference, but like you, I doubt they'd make as much of a difference to get where you're expecting.
Have you driven another XJ, maybe at a dealership, to compare to? It very well could just be that the XJ normally rides firmer than what you expect?
Jaguar is a luxury brand, but still on the sportier side.

 

I side with 12jagmark's comments. Assuming the mechanical suspension and it's electronics are all up to OEM spec, the tires do make the difference. However, expectations of a nice cushy big sedan ride like my old XJ8 were pretty much dashed with the performance emphasis of the XJ (x351). If your expectations and old experience were what you were looking for, no matter what you do, this car won't get there. My original objective was to find the softest ride in a current luxury sedan and, I have to say, the Jag XJ was the softest I could find. The Mercedes sedans were the hardest. I don't care which model, they were all too stiff and jarring. The ride is the main reason, I chose the XJ. The first thing I did on this Jag and my previous one was to get rid of the stiff OEM tires. If your tires are stiff and you want a softer ride, my opinion is to go to Michelins.

 

Freddy, I am not sure if i was able to describe enough, the pattering that im feeling is really unacceptable, when driving say at 120km/h i literally see the empty seat next to me shaking like crazy over the slightest road imperfections and by that i don't mean small potholes, i mean not super flat pavement. I live in the uae and the roads are perfect, i don't see how tyres can give such bad ride, i can feel the vibrations in my lower back 😂 it's driving me crazy. I am not expecting a rolls royce ride quality from an xj but at least to get a comfy ride, it's pretty tiring for me. I reached a point where I started thinking to get rid of it and buy a lexus 😭

 

i found a 2018 3.0 with 45000km at a dealership, it has 20" wheels, i will test it and see how it drives. if it does not have any suspension issues im sure it will feel better than mine. Below you will see all the work that has been done on the car including the work done on suspension

 

I also replaced the upper control arms in front.

 

the mechanic said the upper arm and its bushes are in good shape there is no marks of cracks or wear, you mentioned earlier the tesla, i drove a model s a while ago and it was smoother than my xj and more comfortable on an uneven tiled road surface.

 

My Tesla is a model Y and it is only better at smoothing out potholes and sharp bumps (ie damper related stuff). For all other scenarios my XJ is a smoother ride. Once I change the struts, it should be perfect.

FYI my mechanic also thought upper control arms looked okay. I think it’s pretty hard to tell how good the bushes are without removal. Though my thinking was if all other suspension bushes are wearing out, these ones probably are too. Had them changed and it made a difference. Having done all this work piecemeal was costly though. I would recommend trying to replace most wear and tear items in one go, as the repeated labor fees waste more time and money than the extra parts.

Of course your shocks/struts or mounts could also be bad, but I can’t comment on how they change ride comfort as I haven’t changed mine out yet.

Best of luck!




Cracks in rubber

Hard to see cracks around middle

 

He replaced the right shock and both shock mounts a while ago, so the left front shock is still old, others suggested that it might be faulty and its valve is stuck shut giving a harsh ride, not sure how can we know if it is the problem. Earlier they told me to scan the car with the JLR SDD scanner since it scan deeper in the car and dig for codes...

 

The car does not feel sturdy and because of the pattering the interior is rattling and the ride is all over the place, just like super cheap cars that have no structural integrity 😭

 

I don’t see you missing much other than the upper control arms and sway bar bushings. Maybe confirm with your mechanic what else is left that could cause the issues your seeing. I think he could also wiggle things around with a crow bar while the car’s up in the air to see where there might be any play.

 

Hello, update: upper control arms replaced (these things are super light weight!). But the thing that made the difference is replacing the old shock, the front end is much sturdier and the braking behaviour changed as now the car doesn't lean forward much when breaking and the front became slightly higher and more level with the rear. The ride is way better than it was but leaves more to be desired and I can still feel pattering, probably fitting more expensive tyres with lower wear rating will help a lot (mine have 500 wear rating). The only thing remaining from the original suspension is sway bar bushes, not sure how much replacing those will improve the ride, as they don't seem to have cracks in the rubber, though they might have dried and hardened with age. Any other ideas?

 

Check all the possible parts for front suspension in this diagram here:

Front suspension

Have all of these arms or bushings been replaced? Note there are two lower control arms.

 

All the FRONT suspension parts that got replaced:
1-front lower control arms and bushes
2-upper control arms and bushes
3-left and right shock absorbers
4-shock mounts
I checked and the rear lower control arms are still original, as well as stabilizer bar bushes. How much can those affect ride quality? And any other components could affect ride quality?
​​​

 

Some thoughts:
XJ have active damping on all four shocks. The body control system read ~25 different sensor from the car and adjust the damping based on the data of these sensors. These include throttle, engine load, brake, steering, yaw, ... All sensors are connected to the CAN bus. The actual shocks are communicated by PWM signal and working so that less power equal Hard and full power (1.5A/shock=6A total) are softest setting. (this info are from XJ repair and service manual, available from Sticky section of this forum)
Counting all these together my thoughts:
- Are your engine tuned? The body control read the values from engine mangmen, so if the ECM are programmed wrong, it could request hard damping all the time?
- Do you have any 3rd party device connected to the OBD/CAN? Exsample these chinese external HUD devices? These can cause problems to CAN addresses. Might be that the signaling are harmed?
- Does you car have resent battery(s). Some models have 2. Been noted that when battery have low output in winter time, (can be as low as -30C (-22F) here) the dampening are very hard. (ok, the oil is also hard inside damper and so are tyres) Dampers use quite much power all together. Turn off all other power consumption to check if the dampening change.
- Does your steering wheel vibrate? Body control module read steering angle. When you turn left, right side dambers go harder to avoid leaning of the vehicle. Steering vibration will throw steering angle side to side, so both sides will be constantly hard. (learned this when my front low "banana" arms inner bushes went bust)
- Are wires connected to the shocks? Check engine bay: Top of the shocks should have plug/wires connected. You should have error in dash if they are not connected, but never know for sure... If the wires are not connected you sure have hardest damping.
- The Jaguar SDD (Sympthon Driven Diagnostics) software, what are the factory diag software, have test for active suspension/damping system. Have your car been on this test? Results?

I hope this helps.

 

all what you mentioned does not apply to my car and no error showed on the dashboard. i did not scan the car with SDD.

does anyone know if the front lower REAR control arm affects the ride? what about the sway bar bushes?
thanks

 

Ok, good. Some points taken out. In theory sway bar inner bushes could seize, but movement of these in normal drive are so minimal that this should not effect like you descripted it. It is possible to test by removing one end of the swaybar link and make a test drive.
One more possible come on my mind: What are your tyre pressures at the moment? x351 suspension are "proper" made and really work well only with recommended pressures. Pressures are found from sticker on drivers doorwell. (if i remember right basic are 2.2 bar)