Well, after 6 months reasonably trouble free X350 ownership, I have my first big problem! Rear offside suspension has sunk all the way down & won't raise. Had a quick word with a local Jag specialist, he's having a proper look after the easter weekend but has said as it's just one wheel - it's unlikely to be a leak in the system & is probably the air shock that has failed. My only option is going to be a second hand replacement. Has anybody on here had a successful repair in similar circumstances? (just one shock replaced with second hand) It worries me a little, mainly because of potential wear to the hydraulic part of the shock, even if the air bladder holds. If this was a regular shock/spring assembly I wouldn't even consider second hand, or replacing just the one. Any advice please?

 

Could be an air line. Possibly the height sensor is off or malfunctioning. Make sure you check these things first.

Second hand is the most cost efficient route and best way to get OEM quality installed (unless you want to spend a small fortune on a OEM replacement)

The hydraulic part of the strut usually holds up real well.

You can also opt to get a non OEM replacement as well. Personally, I'd opt for a second hand air strut.

 

I've managed to find a reasonably priced second hand unit on ebay. No idea what kind of mileage was on the donor car though, would it generally be a good idea to order a new lower bush for the replacement unit? I have my reservations about used suspension components & don't want to have to do this twice!

 

First off, the damper part of the unit has nothing to do with ride height, that is all maintained by the air spring part of it via the Air Suspension Module. When the car is shut down and standing, it wakes up every so often and tries to keep the vehicle level, but doesn't use the compressor. Your car sinking at the rear offside may not be a leak, but a displaced height sensor. Of course it may also be a leak from the air diaphragm in the air spring too, naturally.

You haven't mentioned any fault message on the dash display; is there one ?If there is, there will be at least one fault code recorded. Get these read then post here again.

I never had any problems with the air suspension in my previous X350, but I did buy a complete set of "Comfort" NOS air spring units to replace the "Sport" ones on the car. There is nothing wrong with used units provided they have come from a car with a reasonably low mileage and are warranted as keeping pressure. In this regard, these air springs have a valve that prevents total discharge of the air in the spring, (they are charged-up at the factory when new). This is to make it very difficult to rotate the unit top from bottom and thus twist the air spring diaphragm and damage it. So any unit you buy should have this residual air pressure in it. If it doesn't it is suspect. Other part that can leak is the top seal, but this is normally very slow.

Or you could try to do what I did, buy an NOS one. It's that or buy new, but don't buy from a Jaguar main agent, as the Bilstein originals are available on the aftermarket at much lower prices. Even so they are not cheap !!!

BTW, there is nothing wrong with replacing a single air spring unit.Unlike steel coils that can sack-out and thus need replacing in pairs, the air spring has no intrinsic "springiness", the spring is entirely made of air pressure from the air reservoir and height maintained based on height sensor transmitters telling the ASM what the vehicle height is.

 

There was the standard "air suspension fault" yellow warning on the dash after a few minutes of driving. I'll have to wait for the specialist to retrieve the codes though - my scanner won't do that. The suspension has always felt a little softer on the offside, both front & back, I'd assumed I'd got a bush or two worn. I'll get the garage to look at everything so I'm sure. Have pre-emptively ordered a used air shock.

 

Make sure you've bought a "Comfort" spring. This will have a green sticker at the top, the "Sport" ones have a red sticker.

 

I've speedily cancelled my order! Turns out the level sensor bracket on my OSR wheel was corroded & broken. Temporary fix with cable ties, suspension system reset - car level & driveable again! All my air shocks are fine, although the lower front OS shock bush seems to be knocking. Thanks for the advice, happy to be back on the road!

 

Glad to see the problem has been identified. Experiences on this forum show that it is the air suspension system ancillaries that tend to fail, not the air springs themselves.

The lower shock bushes are definitely not long life parts ! Understandable when you look at one and realise that the whole weight of the car rests on four of these, two at the front on the wishbone straight arm, and two at the rear on the bottom of the shock itself. The rears are quite easy to swap out, but the fronts can be difficult due to the securing bolt seizing in the bush. Many shops won't give quotations for this reason, only estimates. The technician at a shop I used to use until they packed-up told me it was sometimes necessary to remove shock and arm together, take to the workbench and hacksaw the bolt off.

 

Does anyone know how to tell if a vehicle was originally fitted with comfort or sport air shocks? What is the difference? I was under the impression the only difference was the calibration of the air shock.

I see SNG has both comfort and sport listed on there site and from my understanding is OEM were Bilstein's. But Bilstein only has one version available.

Thanks.

 

XJR vehicles are fitted with sport. All others have "comfort" including the SV8

 

Not totally right. The models with the word "Sport" on their designation had "Sport" air springs. I know because I replaced mine with Comfort ones. The air chamber in the air spring is smaller on the Sport units, the dampers are identical.

 

hello
my car stays in the high position and when I deflate the suspensions with a diagnostic device it works at the rear but not at the front and I don't know what the problem is

can you help me thank you