Another air suspension failure

Hi guys,

I used to be pretty active on the old Jag forum, having even written a few bits for one of the online service manuals when I was wrenching (a lot) on XJ40’s and my Xj81.

Anyway, I bought my wife a new X350, parked my XJ81 in my car shop, and enjoyed a Jag covered by warranty. I bought three new Pontiacs when they went kaput, and we’ve been driving those as daily drivers.

Fast forward about eighteen years, my wife’s Torrent GXP got struck by lightning and is a total, so I have un mothballed her Jag and she has been driving the X350 for a couple of weeks, but now the CATS air suspension has failed, and now it is sitting on the bump stops on all four corners.

I do not have a Jaguar specific code reader to pull the unique Jaguar codes. The fuses and relay are good. It sounds to me like the compressor is running - I hear a pump start a few seconds after engine start which times out after around a minute, which I suspect is the air compressor. The fact that it is low on all four corners, and that I can hear the compressor running (never heard it before) suggests to me that the compressor is the point in the system that has failed, although sitting in the car it feels like it is trying to lift. Prior to going completely down on all four corners, it was intermittently throwing the air suspension fault (orange) flag in the cluster when the system was not seeing the required pressure in the correct amount of time, but was otherwise functional.

So on an almost twenty-year-old system complex car, I’m wondering about the best way to go on this. The car only has 48K miles and is pretty much like new, but I can’t imagine that it has much in the way of actual cash value at this point.

I see that compressors are available for not a lot of money. I also see complete kits are available to just get rid of the air shocks completely. Are there any recommendations out there for a good vendor on replacement struts? Or for vendors on air suspension components? Time is on my side - sort of - to sort this out. She’s driving my G8, while I have pulled a pretty much new Solstice out of mothballs to drive. But it’s small. Really small.

Having had the X350 from new, I am well aware of the capability of the C.A.T.S. suspension when it works properly. On the other hand, I have to think that all the lines and sensors in the system are likely just to become more troublesome going forward, and maybe it is best to get rid of it while replacement parts kits are available.


Fort Smith, AR
2004 X350; 1994 (short wheelbase March '93 build) XJ12

Win: I, too, have not been on this forum for a long time, but my now-defunct '06VDP had two instances of collapsed front shocks, the first with a prior owner who had a garage, which I lack.

I paid for one replacement, then vowed that at the next sign of leakage from the bladders I’d convert it to the coil shocks Richard Green references. All the messages I saw at the time (pre-defunctness) were as Richard indicated: the ride was just fine. I did like the fractionally softer, more subtle ride with the air shocks, but they historically have been a pain in the patootie.


Hi Eliot - I think I remember you from the XJ40 forum?

I’m leaning toward going with coil overs, but haven’t really decided yet.

I downloaded the hardware guide for the '04 XJ8 and studied it to fill in some holes in my knowledge of exactly how the system works and where all the bits are located in the car. The system has a lot of potential points of failure, which I think does not bode well for a nearly two decade old car going forward, but I’m going to check all the easy stuff - lines, fittings, etc., before I make any decision. It’s at my other house right now, so it will be a week or two before I can back to look at it.

All the vendors I’m familiar with look to be gone - Coventry West has shut down. Looks like Jagbits is still around.

At least a flipping door handle never broke on it! Actually, it’s been a terrific car. It had a lazy fuel sender and a rattly seat belt tensioner replaced under warranty, and that’s been it. This is the first real trouble it’s given me.