Will you get an error code? First time poster here but longtime Jaguar owner. My 2004 XJ8 I recently purchased makes my 6th Jaguar and I can't seem to get the bug out of my system.

Problem is, the compressor was replaced prior to purchase (and the car received a clean bill of health from the dealer in Louisville, KY) but I've noticed on country roads that are a bit uneven and bumpy, that the ride quality just seems a bit harsh. I've also noticed when parked in uneven or odd positions that the left rear of the car sits quite low, not being enough space to comfortably place your hand under the fender and touch the top of the tire. In my garage, overnight, the car seems to sit quite level.

Am I being paranoid? Am I also not taking into consideration in ride quality that the car has a brand new set of Z rated 18" Michelins hitting the pavement? Should I expect the "harsh, sportscar handling" and bumpiness or is it likely I have a legit problem here?

Unsure if the car should sit even on all four corners simultaneously, all the time so I figured I'd ask the experts. Open road on smooth pavement the ride quality is just fine.

Please tell me if I am overreacting...or simply not used to the fact that an XJ8 is a bit more sporty than my 03 Town Car, lol.

It HAS been about 4 yrs since I've been in a Jag so I'm due to get a little slack ;0)

 

Hi,

On the air suspension, the rear "corners" are independent and individually fed from the reserve tank via the distribution block. The front "corners" are daisy chained together. Thus, you should never see a low front corner. If you see a low rear corner, this could have a couple of causes, one of which is a leaky air spring, or a height sensor that has lost its way, either of which should set a fault code.

All that said - You can literally set (and store) a wrong height on one of the rear corners. I personally do not have the factory WDS or SDD to setup the ASM, but techs have mentioned that the factory specs have one rear side (I believe the driver's side) set slightly higher, but it shouldn't be noticeable by eye.

Finally, if you're sitting level on all four corners consistently on a level garage floor, especially if you leave the car there for more than 24 hrs W/O opening any doors/trunk, etc., and it still sits level, then you're OK...not to worry...drive it and enjoy...

BTW- On the official "Sporto-meter": X350 vs. 03 Town car....I donno...let's ask the "judges".

 

Thanks Steve.

I am OCD when it comes to my autos and I want to keep my first XJ8 in the best condition possible and want to learn it, front to back if possible, and maintain it accordingly. It truly is a beauty and is hard loaded: front/rear htd seats, htd steering wheel, nav, xenons, 18" dynamics, black on black-no paintwork or accident damage and has 86k on the clock. Picked it up from a friend for $12k who had owned the car for 2 years.

So, let my foray into the world of the X350 begin

 

We'll help you keep your car in perfect running order here. I have the same X350 as you - Black/Black; all the same equipment except the rear heated seats. I have 20% window tints (legal where I live) as I am in a warmer SW climate. Of the three Jaguars I own, and I love them all, if times ever got tough and I have to sell them, the X350 stays under all circumstances! The 350 is an engineering marvel IMO.

BTW, you think you're OCD - you should see me...LOL!

 

Good to see another member in KY! I'm in Louisville myself. Let me know if I can help you in any way. I recently joined the local Jag club, and would be glad to get you some info if you're interested. We have a big event coming up June 4th and 5th, hope you can make it out..

With regards to the air suspension.. As long as it maintains height while driving, and it raises when started I probably wouldn't worry about it too much. I have noticed that mine sometimes settles in unusual ways, but when started comes back up to normal. I've never really had a complaint about ride quality though, even with 20" wheels and 35 series tires.

 

The car is designed to adjust or level to the conditions. If you are on a uneven pavement it will adjust to that condition. If she is sitting level on level payment...I don't think you have a problem. While the car is off it will check every 24 hrs. that the suspension is level. It will release air in the shocks to level the car to the lowerest shock to not run the battery down. There should be other posts on the suspension and one guy said to disconnect your battery and let the car sit a day or two. If one of the corners is low, you have a leak. The system has many codes for the suspension from shock position, pressure, and time it takes to fill the resorvior. So, no code, you should be ok.

 

Large wheels with low profile tyres will make it seem more "sportscar like". My XJ6 Sport has the 20" Sepangs and it is fairly good on ride, but not the boulevard ride I remember on my 1980 XJ. That was on 205/70 VR 15s. Twice the aspect ratio of the Sepang tyres (35%)

 

Thx a bunch for all the info, fellas. I will certainly say the Michelin Pilots do their job in the handling dept but boy, are they noisy lil fellas, especially on roughly paved country roads here in KY. Get some edgy pavement and it'll drive ya batty.

What is everyones insight into the "floatiness" of their XJ? What do you feel is the level of float compared to the leve31l of stiffness the car provides? I feel the ride quality is awesome but I catch quite a bit of float if I hit a bridge or change in pavement height in general.

Btw, 310, I'd love some info on the club meeting as I know my friend is a member and will likely attend. I've simply neglected to ask him about such. Also, you say you enjoy the ride quality out of the Sepangs, which I consider the BEST wheel option for the car physically. What rubber do you have meeting the pavement?

Many thanks

 

I have Michelin Pilot Sports (all season) and I can't complain. I have heard they get louder as they wear. I was driving a 2000 Cherokee before this car. So the Jag could have stone tires and I would still think it was quiet.

 

I think mine can be a bit floaty at times.. I don't know if it's just a placebo effect, but I think it is a little better with sport mode turned on (stiff shocks..?).

Shoot me a PM with some contact info and I will get you set up. I can drop a registration packet in the mail for the councours if you'd like. Who is your friend that's currently a member?

As far as rubber, right now I'm running Falken 452s in the stock size of 255/35/20. Ride quality is surprisingly nice, and any road noise is easily drowned out by having the radio on.

 

I admitted my ignorance in a PM to 310 that I wasn't even aware that Sport mode toyed with the suspension as well. Owned these darn cars for over a decade and I learn something new everyday, lol.

So, with 87k on my clock now and a clean bill of health from the dealer last month, what should I be looking forward to doing, preventitive-wise, in the next few thousand miles? Considering a doityourself plug change ASAP as I figure it's about that time.

Those little devils easy to get to or are one or two of them placed where you need to hire the services of a snake that knows how to change spark plugs?

 

That is probably because it doesn't. It does on the newer Jags but not on the X350.

 

U10-- I'm fairly certain you are mistaken re the air suspension on the XJR (350) in sport mode. Perhaps the models sold in NZ are different than US but any number of posts on this forum and in my owners manual speak to the changes made to the suspension set-up in sport mode.

Goobe-- after 87K miles you need to flush out the brake fluid. Ky has very cold weather on occasion and you risk locked up brakes in zero conditions. It happenrd to me in Alabama some years back with a 6 yr old Buick.

KBO mates.

 

My experience with the car in sport mode is a noticeable decrease in the traction control system; along with much faster throttle response. Either that or my heavy foot is too quick for the traction control system? I can't say I've noticed a difference in the suspension stiffness.

 

That doesn't mean to say they are actually correct. This is from the standard owners manual:

The switch marked S on the J-gate surround enables the driver to select
either normal N or sport S modes. When sport mode is selected the automatic transmission will operate normally, but the gearshift points are
extended to make full use of the engine’s power reserves.

In addition to the switched transmission modes (N and S) the transmission control module will select shift patterns to suit specific conditions.

No mention of suspension.

And this is from the factory training manual:

The sports mode strategy moves the transmission shift characteristics so that upshifts occur at higher engine speeds and downshifts at lower pedal angles.

Unique to this transmission is the electronic brain of the 6-speed ZF automatic transmission The TCM incorporates adaptive strategies which improve the accessibility of the vehicles performance in demanding driving conditions while maintaining a relaxed driving experience when cruising.

In Sport mode, throttle pedal usage and cornering behaviour are monitored to assess driving style and road conditions. When an enthusiastic driving style or a demanding road is detected, sixth gear is inhibited and the lower gears are made slightly more accessible in order to prevent unwanted
huntingr between gears.

Conversely, when cruising conditions are detected, 6th gear is once again made available to maximise driving refinement and economy.

Under conditions of heavy braking, the transmission will perform one or more downshifts to improve response to a subsequent throttle pedal application. Similarly if the throttle pedal is released rapidly (Fast off) following hard acceleration, one or more upshifts are inhibited to increase engine braking and also improve subsequent response.

To complement these features, when a corner is detected transmission upshifts are inhibited. This inhibition is maintained for a short distance after the corner allowing the driver to achieve a smooth balance without unwanted shifting mid-corner.

No mention of suspension.

The adaptive damping sections have no mention of sports mode either.

 

I never said it for sure did.. I didn't think it did, hence proposing it as a question...

 

As per my earlier post, I was responding to you calling yourself ignorant for not realising something. I was just saying the reason you weren't aware of it is because it isn't true.

You are therefore correct

 

Always cool to learn something each day

A brake flush is a good idea as I am unsure if it has ever been done. I will put that on the agenda.

 

This may interest you then. It is from the X350 factory training manual and is describing one of features of the updated Teves ABS:

Launch Control

The launch control feature maximises the standing start performance.
This is achieved by satisfying entry conditions which include:

Vref < 18 mph (30 km/h)
Lateral Acceleration < 1 -2 m/s2
Vehicle Acceleration >0.3g

The launch control minimises the brake intervention and optimises the engine torque in order to provide the vehicle with optimum acceleration.
During launch control activation the customer may experience some tyre noise.

 

Ditto on learning a few things too! If I get any smarter there will have to be 2 of me.