Hi everyone. I have a 2004 XJR that's too low (27" ground to fender rim) on only the front driver's side. All of the other three wheels are the correct height, so I'm thinking this is not an overall systemic issue. OBDII Actron scanner only shows P1111.

When I start the kitty, the "VEHICLE TOO LOW" error shows immediately. After about two minutes, the compressor audibly starts trying to pump up the left front wheel (I can hear the hissing), but it only gets the wheel about 1/2" higher (still slightly more than 1/2" too low) before the compressor gives up and the "AIR SUSPENSION FAULT" warning starts alternating with the "VEHICLE TOO LOW" error. The front left wheel then sinks back down to 27".

A few days earlier, only the "AIR SUSPENSION FAULT" warning was coming on, and only after driving the car for a few minutes. Turning the car off and restarting would make the warning go away for roughly the same two minutes or so that it's now taking for the compressor to kick on. Only now, the compressor isn't getting the wheel back to the factory spec height, and I'm stranded here at home as a result.

So what am I looking at here? A busted air shock? A kink in the line? Any suggestions on anything else I should try will be warmly welcomed and appreciated.

Thanks!

 

It sounds like the air spring diaphragm has failed on that side. If you can find a supplier that puts on new diaphragms it wont be too expensive, but new OEM units from Bilstein are around £700. I'm sure I read a post last week where a US supplier was suggested.

Arnott Industries used to do replacement diaphragms, but only supply new units now, and whilst these are cheaper than Bilstein, they don't have the variable shock absorber, so you would lose the CATS system.

Or there is eBay for a used unit. You might be able to find NOS (New Old Stock) too, like I did. Be careful, because the units are of two types, Comfort and Sport. Comfort have a green spot on the unit, SPort a red spot, but to see it, you'll likely have to remove the shock, but you'll haver to do this anyway when you replace it. SO if you are OK for the car to stand a while, take the failing shock off.

 

Hi scooternva,

The P1111 Diagnostic Trouble Code (DTC) indicates that since the last time the system memory was cleared of all DTCs, all engine management OBD diagnostic monitor drive cycles have been completed. But since this only has to do with engine management, you may still have one or more air suspension DTCs that may begin with the letter B (Body), C (Chassis) or U (Undefined, mostly network-related). To read those codes requires a dealer-level diagnostic system or a high-end third-party system capable of reading proprietary Jaguar codes.


As Fraser notes, it is possible the bladder in the air spring has developed a leak, though it must not be large or the compressor would not be able to cause it to rise at all. You can test for a leak in the bladder by running the routine you describe above, then immediately turning off the engine and stepping out of the car to listen for escaping air from the front left wheel well.

If you hear leaking air but it seems to be coming from the engine compartment rather than the wheel well, try spritzing a little soapy water around the top of the air spring/damper unit, especially the air hose fitting and the seal around the center plate, taking care to not wet the electrical connector for the ECATS solenoid. Bubbles indicate a leak. Leaks are fairly common at the air hose connector and at the rubber top seal around the center top plate. Hose connector leaks are usually simple to fix, but there is not yet a DIY fix for the top seal.

In addition to a probable air leak, your compressor piston ring seal is no doubt worn and in need of replacement. That's a DIY repair using an inexpensive new piston ring from our forum member Andy at bagpipingandy.com.

Figure out where your leak is and we'll help you move forward.

Cheers,

Don

 

I got the red light and the "vehicle too low" warning two days ago when I backed the right rear tire up a little on a bank, but it went away when I drove forward again on more level ground and it has not returned and in fact I didn't get the usual "air suspension fault" message at all when driving to our club's car show last Saturday.

I see the warning here about "comfort" VS "sport" shocks. I had my 06 SV8 on a lift at our club shop and took photos of the front shocks that were said to be replaced by the car lot that sold it to me, and the tag on the right shock says "AS-2710, Assembled in USA 18.09.14", and in smaller numbers "AS-2710000004678", and the left shock tag has the same wording with the serial number AS-2710000004679 so I assume they are new. I did not see a red or green dot, although there is a green symbol that looks like a big A above a "do not open, do not heat sticker"


Anyone know if these are comfort or sport shocks from those numbers, and if they are a type of air shock that inhibits the CATS system? Also, the closest Jaguar dealer gave me the key number and a CATS number of 6546; What does that number mean?

 

It sounds like you have non-OEM units on your SV8, probably Arnott. OEM are Bilstein and made in Germany, (or at least somewhere in Europe)

 

Right you are. I looked up the part number and thay are Arnott units, $446.45 on Amazon. The info says direct replacement for OEM (or maybe it was "OE fit"). Would these operate differently than Bilsteins? I tried the Arnott web site for info, but it doesn't load - must be having a bad day.

Here's what one supplier says:

ARNOTT INDUSTRIES AIR SPRING: AS-2710
Specifications:

• Brand New Arnott Air Spring
• Sold individually - Fits either LH (Driver Side) or RH (Passenger Side) FRONT
• Custom Designed Monotube Shock Absorber
• CNC-Machined Aluminum Components
• Valved to ride like OEM Suspension
• Include Upper Mount, Mounting Bolts, Rubber Bump Stop, & O-Rings
• Built to strict quality control standards
• Fits models with either Sport or Comfort Suspension

Vehicle Fit

• 2004-2009 Jaguar Vanden Plas Air Shock (Arnott) Front Driver or Passenger Side
• 2005-2009 Jaguar XJ Super Air Shock (Arnott) Front Driver or Passenger Side

 

The air hissing is definitely coming from the wheel well. I did the soapy water trick to confirm and there are no bubbles where the shock is mounted to the chassis in the engine compartment.

Does this tend to indicate that the shock itself is the problem? Thanks...

 

Hi scooternva,

Unfortunately, this probably does indicate a leak in the air bladder, and so far we are not aware of a DIY repair. Your options include:

1. Replace the bad air spring/damper unit with a good salvaged unit (eBay is one potential source).

2. Exchange your bad unit for a rebuilt original Jaguar/Bilstein unit if you can find one (Arnott Industries used to perform this service but we've had reports that they will no longer rebuild original units. There may be another company that can do so).

3. Replace both front units with Arnotts' new proprietary design air spring/dampers at the expense of losing the ECATS adaptive damping functionality (some owners say they miss ECATS, some say they can tell no difference).

4. Replace all four of your air spring/dampers with conventional coil spring-over-shock units by Arnotts or one of the other companies that offers direct replacements. You will lose the ECATS as well as other functions, such as automatic leveling to adjust for passenger and luggage weight and to reduce front end lift under acceleration and diving during braking. You will also lose the inherent complexity of the air suspension system. Search this forum for reports from folks who have converted their cars. Most are at least reasonably happy with the results.

For the record, I intend to keep our air suspension operating as long as I can, but the day may come when there are even fewer options than I've listed above.

I'm sure other members will be able to provide additional suggestions and support.

Cheers,

Don

 

The car is already fitted with the Arnott units, so it is a matter of either seeing if there is any warranty on them at all, and claiming if there is, and if not, then buying another unit at the stated price of $447

 

Thank you for your help Don and Fraser. I'm giving the Arnott coil spring conversion kit (p/n C-2290) a long, hard look. My 2004 XJR has almost 90,000 miles on the odometer now, and I can easily see spending another $1,100+ to replace the rear air springs sooner than later (everything I've read about X350 air springs tells me it's not a matter of if they will fail but when), not to mention all of the other possible failure points in the ECATS infrastructure.

If I do decide to go that route I'll need to locate a service center that can perform the conversion--I don't have a lift and even though the video makes it look easy, I've only performed my own routine maintenance on the Jag thus far; replacing the springs is a little advanced for me.

 

Nobody knows why, but the fronts seem to fail more often than the rears. This may be because they are close to the heat of the engine bay. BTW there is no need to replace in pairs, as the air spring never sacks-out like steel coils, so if a unit has gone, you fit another, assuming the shock part of the unit is OK and not leaking.

At 90k miles your car is not yet near even half its potential life. Many owners have cars in the 200k range, many still on air springs. If it were me, I'd just fit another Arnott unit, or replace both of them with Bilstein originals. Here is what a UK supplier is charging:-

https://www.britishparts.co.uk/produ...pring-C2C41347

There are also quite a few used ones on eBay too.

AIR SUSPENSION DAMPER "SPORT" F SHOCK ABSORBER Jaguar XJ6 XJ8 XJR 2003-2005 X350 | eBay

 

Fraser,

Note that we have two different owners with air spring issues posting to this thread.

For Phil, whose car has already been fitted with Arnott air springs, replacing only one with a matching new unit should be fine.

But scooternva, the OP, still has original Jaguar units. I assume you are not suggesting that it would be prudent to replace only one front unit with a non-matching new Arnott unit, unless it were one of their rebuilt original Jaguar/Bilstein units, which I understand are no longer available...?

Cheers,

Don

 

It's kind of a moot point since I've already decided to go for the two point conversion (or in this case, four points), but everything I've read says that air springs should be replaced in pairs...?

 

Hi Don
Sorry if I'm getting confused a bit ! I agree that all four spring units need to be the same manufacturer, so Scooternva needs to either replace the defective unit with a new or used Bilstein original, or convert to all-Arnott air, or Arnott steel coil, and dump the Bilsteins. I have to say, if it were me, I'd be reluctant to dump the Bilsteins as so many people seem happy to do. Bilstein are one of the top makers of car dampers and have a long history of engineering excellence, I even have their shocks on my MG TF.



I think buying a single Bilstein original unit shouldn't break the bank, after all what does a conversion cost ?

 

I didn't mean to confuse the issue, Don, sorry. Since my car had already been fitted with new Arnott AS-2710 units on the front when I got it, I was just asking how they would affect the CATS system. From what I read here I assume they don't have variable damping but will still adjust the level and ride height of the car as the OEM shocks would. Is that a safe assumption? I watched the Arnott installation video and no mention was made of height sensors or any adjustments to ride height needed. True?

 

Hi Phil,

I am not an expert on the Arnott units, but my understanding is that their proprietary air spring/damper units use the original Air Suspension Control Module (ASM) and height sensors to maintain the proper ride height and leveling. So if any adjustments are ever required in the ride height they can be done using SDD just as with the original air spring/dampers.

As far as I know, the only functionality that is lost is the ECATS adaptive damping, which varies the shocks between Firm and Soft damping rates depending on conditions (speed, anti-lift during acceleration, anti-dive during braking, etc.). The Arnott units have an inductor coil or similar device to which the ECATS connector attaches. The coil provides the impedance expected by the ECATS control circuitry (ECATS control is built into the ASM), so the CATS FAULT won't be triggered.


Hopefully a more knowledgeable member will correct anything I've gotten wrong.


Cheers,


Don

 

Thanks, Don,

That is pretty much what I was thinking about these front units. I would guess then that the rears would have adaptive damping if they are still OEM, although at 127K miles they could be replacements too; I guess I need to get it back on the lift and check them out. So perhaps mine is half an ECATS system or another way to skin a CATS?

 

2004 Jaguar XJR with new Arnott C-2290 steel coil springs installed

All done! The Arnott steel coil spring retrofit is complete on my 2004 Jaguar XJR. I just finished a 30-minute test drive that took kitty on freeways and surface streets at a variety of speeds, curves and road conditions to get a sense of the new vehicle dynamics. So far, the verdict is that it's slightly more transmissive of bumps in the road (which was to be expected), but it's definitely not a harsh ride by any means. The car rides roughly an inch higher than it did before, but as you can see from this profile shot it's not an objectionable difference.

There is one huge difference, though: being able to drive down the road with peace of mind, knowing that I will never be stranded by an air suspension issue ever again.

 

Coil springs can snap too ! I had a Rover 75 that had to have a mod done to prevent a snapped spring from tearing into the tyre. The suspension was Macpherson strut, so slightly different, but still coil-over-shock.

I only ever had a rear coil snap on the Rover, and recently my wife's New Beetle also had to have a rear coil spring.

 

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