Hi. I have owned an '04 XJR for 2+ years. I bought it at around 35k miles and it's currently at 54k. Car has largely been babied. I like it a lot, but am worried about air suspension upcoming costs.

The air suspension warning light started coming on about 4 weeks ago, corresponding to low local temperatures. I don't have any problems with the car being too low. I assume I have a compressor that is losing strength and is triggering the warning because it is taking too long to fill the shocks.

I have read through as many air suspension threads as I could. I think I know what my choices are, but as a newb, would love confirmation:

1 - I can repair the piston ring on the compressor (from our Audi friend via ebay). I should expect the shocks to fail over the next 0-50,000 miles. Replacing the shocks with rebuilts would cost roughly $500 a pop or over $1000 each for new, depending on actual labor costs - so roughly $2500-5000 in upcoming repairs, with the cycle repeating every 50-100k miles. (note - waiting to hear from people on whether they were successful in renewing their compressor with the new piston ring)

2 - I can replace the compressor for $700-1000. Shock failure same as above. So closer to $3000-6000 over time in eventual repair costs for the suspension over the next couple of years.

3 - I can replace the air suspension now with a coilover package, either from Arnott or Black Dog - for $1500-1800 plus labor. If I do this, I don't need to fix the compressor. My ride will likely be softer than before. So I can bite the bullet now for around $2000-$2500 and sleep easy, but my car will be a little less good.

Is that roughly right? Thanks in advance.

 

4. try to find your leaking shock and/or line and repair or replace the offending shock (rarely do they leak in pairs). Save the compressor from dying at the same time as your shock. Then, do the $100 compressor repair and sleep better.

Just giving you options.

 

Read the fault codes first. C2303,(I think that is it !), basically tells you the compressor is on the way out, so you can do your cheap piston seal replace job on that and see if it fixes the fault. If not, and you need an air spring, Arnott also do rebuilt and new air springs at lower cost than Jaguar ones. Jaguar ones are also available on the new but are not cheap even if less than main agents charge.

I find it puzzling reading about air spring failures in the USA. My own local independent shop has never changed an air spring, and he has these cars in most weeks.

The later XJ only has air springing at the rear, fronts are coils. I think Jaguar went a bit too far in 2003 with a full air system. Previous models rode perfectly well on steel coils.

 

You can replace a compressor for $300. I have the coilovers and see no difference in the ride. Cost to you depends on your mechanical ability. If I were you I would go with either the new air units or the coilovers from Arnott. I chose the coilovers and stripped out all of the air components. I no longer have to worry about fault messages or finding my car sitting on the stops.

 

Thanks to all.

First, I guess the core problem here is that I don't fully trust my local mechanic. It's just a feeling I get that they will find problems and then fix them at the highest possible cost.

I'm not mechanical, so I'm dependent on a good mechanic. My local mechanic wants something like $140 to pull the codes and do an initial diagnosis.

XJ8 Red - did you compare the Arnott coilovers with the Black Dogs? I'm very tempted to swap suspensions and gain piece of mind for the next 100k miles vs. doing the compressor now, then a shock later, then another, and so on.

 

If it was me I'd fix the suspension, (probably the compressor, the mileage is about right for a failure), then see how you get on with the car. If you get further trouble and its an air spring, then think about what to do based on how you like the air springing.

 

I researched all options. The first set of coilovers Arnott sent me felt like they were coil binding on heavy bumps. They were aware of the problem but had not bothered to let me know. They replaced the front units. They now ride fine. Their tech support is not that great but they do stand behind the product.

 

That's more than (the $125) my Jaguar dealer charges!

Agree with this!

 

My Indy shop charges $120 to hook it up.

 

Took it in to a mechanic who pulled the error code:
C2303 - Reservoir Plausibility Error

He says the compressor is not receiving power.

The good news (I guess) is that there are no leaks. If there were leaks, I would have sagging components.

They are now trying to figure out where the power is.

 

For the future - De Long's Automotive - Campbell, CA
Give them a shot. I'd not say they are the best shop I've seen, but they are good and friendly. Many forum members have had a long history servicing their XJ's, XJS' (Doh) etc with 100% positive experience.

 

Got the car back. The mechanic isolated the problem to the relay not being well-seated and as a result, power not flowing through it.

So they tightened the contacts and I'm on my way. We'll see if I get any fault codes from here.

 

the last two winters my wife's '04 XJ8 has been having issues with the air suspension in cold temperatures...


so she's said screw it, and she's driving my Lightning on the mornings when the temps are lower so her car can sit in the heated garage

 

Thanks for posting the results Hanfrac.

Andy from the Audi forum via Ebay can help with repair kits as you mention if required.

I called down to see him last week as it happens so we could do a live scan on my Audi.
He's a great guy and showed me his garage setup and how he makes the repair kits. He even has a little test bed with a compressor setup to test them..........

All very very impressive if required and he's already helped many many Audi owners with similar issues

 

@JimC64 - the 2 mechanics I've checked with locally won't install aftermarket parts for liability reasons. So if I end up going in that direction, I'm going to need to find different help.
@Nardoswiss - thanks for the referral on DeLongs. I've heard of them. They are just far enough away from me to feel like a hassle. But I suspect I have brakes coming up and maybe that will be something worth taking the car there.

Thanks to everyone who chimed in here.

 

The car may not be having "problems" but rather just doesn't agree with Jaguar's programming.

Basically the Jag software is programmed to throw a code if the compressor doesn't reach a specified pressure within a certain time limit. On cold read: Norther USA frigid winter days, That time limit just isn't sufficient to not set the code.

If the car doesn't lose ride height overnight, and there are NO errors on warmer days, aka above freezing, I think you're just running into the software being too intrusive.

I've had 4 XJR's. Every one of them gave me random air suspension fault warnings when cold started in winter. I've had ONE true air suspension failure.

And it happened in spectacular fashion on an almost 100 degree day in the middle of July. I lost the passenger front air shock. The car just suddenly felt and handled like crap, the hydraulic fluid leaked out of the shock (because once the bag is gone, you Will immediately blow the inner shock), and the car settled into low rider stance. Once it was replaced, the car was fine again.

I think the temperature and humidity variations in the more extreme US climates do a number on the rubber airbags. Interestingly enough, in their home turf of the UK, you rarely hear of an air suspension failure. Yet here it's almost treated as an expected maintenance item.

Take care,

George

 

I can confirm this is true. MY local Jaguar independent told me they have never replaced an air spring. Of course the compressors are a short life component whatever country the car is driven around in. However we now have the piston seal available on e-Bay, so the DIYers can now fix this cheaply. FWIW, I replaced my compressor in late-2010 with car on around 35k. All OK so far at 67k today.

 

Thanks, George. Turns out the relay was not the issue, as I started getting errors again. They are still intermittent (every 3rd/4th time I drive the car). However, now, when I hit the button on the left of the turn stalk to clear the error, it always comes back in about 9-10 seconds. So it's a little different than before.

I live in Northern California. I definitely started getting these faults when it got cold, but cold here is high 30's-mid 40's. I cannot say that it only happens when the temperature gets below freezing. But it does seem to happen when it is colder here. It will be another month or two before it's warmer on a consistent basis. The car has always been housed in this area from new.

Are you suggesting that maybe I ought to wait for the weather to warm? That will be in a month or two. I definitely don't have any actual issues with the car being too low.

 

I still think that's the error you're getting.

First of all, pressing the button on the turn stalk does not clear the fault, it only cycles through the displays on the dash. The car pops the fault back on the display after a few seconds because it thinks that it's a priority that the driver should be seeing. Annoying isn't it. It does the same thing when the damn washer fluid is low.

Now, dont forget that temperature is a DIRECT factor of pressure. Lets say the car's air compressor needs to raise the working pressure of the system by 50 psi to get to where it needs to be. (These are just arbitrary numbers). At 1 degree Celcius (around 34 degrees Farenheit) it has to do 15 times more work than at 15 degrees celcius (around 50 degrees Farenheit). Most of this is to compensate from the working temperature the last time the car shut down, to the new ambient temperature it has reached whilst sitting overnight.

Here's the true test of if the error you're getting is based upon the "too long to get to operating pressure" algortyhm. Next time you start the car and it throws the fault. Let the car idle, or drive the car for 5-10 min. Enough to where pressure will have built up. Shut the car off, pull the key out and lock it, and wait till the electronics go to sleep - I THINK 12 mins. And then restart it. The car should no longer display the "AIR SUSPENSION FAULT" message, because on this start pressure is already built up.

Sounds like you are just at the border of exceeding the alloted time (300 sec if I remember correctly), to get to operating pressure depending on the temp that particular day. Hence the intermittent nature of your faults.

If the compressor had no power you would have a consistent air suspension fault, and you would never be able to replenish the air in the system.

The "relay" theory is just that. Some mechanic who basically restarted the car, realized that the fault went away (or it had gotten warmer by then), and found something to charge you for. (God I hate some of the people in this business sometimes).

Now there will obviously be some sort of wear on the compressor as it ages. Apparently one enterprising fellow on the Audi forum (which shares the same compressor) has narrowed it down to the piston shaft seal, and provides a replacment / rebuild kit. However, a compressor that has gotten to the point of needing a shaft seal replacement is way beyond the occasional intermittent warning when cold. Consider it the first signs of wear. Once it gets past 45 degrees consistently you wont have to worry about the compressor until the fall.

Let me know how you make out with my little experiment.

Take care,

George

 

George,
Thanks for the detailed recommendation.

As mentioned, the error happens intermittently (sometimes on successive starts/drives, sometimes it doesn't show up for days). And as it is warming up, it appears to not be temperature-dependent. I had the car in Tahoe 2 weeks ago in near-freezing temps and the error didn't show. Yesterday and today, it's in the 60's-70's and it's triggering each time.

To your recommendation, today, I drove the car. Fault light comes on. Drove it for 30-40 minutes. Stopped the car, locked it and left it for 20 minutes. Started it up and the fault light came on instantly - it did not wait 300 seconds.

I have read that an inconsistent battery can cause air suspension faults to fire. I believe the car may be on its original battery from 2004. Is changing the battery a possible solution? Can inconsistent voltage cause C2303?

2nd question - given the age of the car, should I just buy the compressor kit from the guy in the UK and get that done?

Thanks again.