Quick request for informed opinions on a course of action.

My wife's 2004 XJ8 runs and rides and looks great, but it has about 155,000 miles on it. The air suspension has been dropping in cold weather for a couple of years now, but raises up when started. It's not cold that much in North Carolina so for most of the year there is no problem with the air suspension. On those cold winter mornings she just lets it idle in the garage for a few minutes and then she's ready to go. But...

The passenger side air shock has finally let go. The "hiss" out of the top is undeniable and the vehicle settles low within a few minutes of shutting the car off. The air compressor can keep the car up when driving, but it comes on every 30 seconds to do so, which can't be good for the compressor. The driver side air shock is a new Arnott replacement unit that was installed about 2 1/2 to 3 years ago; no problems with it. Here is my question...

Given the miles and the fact that warm weather is coming, I am debating whether to replace the failing shock with another Arnott for about $500.00 or just get it over with and do the springs/shocks conversion for about $1,400.00. My wife is kind of tired of worrying about the air suspension issues and the freedom of getting rid of the system all together is tempting, but to put $1,400.00 into a car with 155,000 miles makes me a little bit nervous. Should I put in another $500 air shock and hope the system is trouble free going forward? OR, should I completely remove the air suspension system as a source of stress in our lives?

Thanks in advance for your opinions...

 

Hi Jeff,

I can't make the decision for you and your wife, but I can tell you where I am. I've converted a few X350s for friends and fellow forum members and they are all very happy with the Arnott coil conversion. I have one of the cars here for some other work and just drove it yesterday, and the ride is perfectly comfortable, with the tradeoff that it is not as well-controlled as the stock air suspension. If your wife is not a spirited driver, she might be perfectly happy with the coils.

Personally, I like the extra control of the air suspension, and I love the fact that I can load the trunk with heavy luggage and the car will level and go down the highway with incredible stability. So I'm nursing our air suspension along and living with a leak in the front right air spring top seal that worsens in cold temps. My intention is to replace air springs when necessary and spend $500 to $1000 at a time to keep the system going as long as it makes sense.

The ASMs, valve blocks and reservoirs don't seem to fail, and the compressors seem to be capable of high mileage when serviced to clean internal corrosion and replace the piston ring. The other weak points in the system are the air spring bladders and top seals, and those have to be viewed as "wear" parts. It's too bad no one has yet developed a DIY replacement for the bladders or seals, but the factory construction is crimped together and doesn't lend itself to work by the average home mechanic.

So I guess your decision is to spend $500 on a new air spring/damper and the time to swap one corner and hopefully have at least a few more years of proper air suspension operation, or spend $1,400 for the coil conversion and the time to swap all four corners and add the Electronic Bypass Module, and hopefully have at least several years of trouble-free operation.

That's the best I can offer. I'll look forward to reading the input of others.

Cheers,

Don

 

A lot depends on how many more miles you expect to get out of the car and its overall "health".

One shock is relatively young so maybe going with an an all round replacement is overkill?

Then again peace of mind is worth a lot.

 

If it were me, I'd just fit another Arnott air spring. I am surprised you have a Bilstein on one side and an Arnott on the other, as the CATS system relies on being able to switch shock settings on all wheels. You get away with it because the car is usually driven well within its performance envelope.

 

If the Arnott is 2 - 3 years old it is a rebuild of an original. Arnott does not do this anymore.
I have gone with RMT. The price is way lower than Arnott. So far so good. They replace the top and I assume it will not leak.
I have gotten a cheap price by sending old shock for rebuild. I have a spare front and rear.
The new Arnott do not have active dampening. This is a drawback in my opinion.

 

Here is my take. The machine has been good to you - now be good to the machine. Go ahead and make the conversion.

Down the road there will be more and more air suspension problems and the higher the mileage the less sense it will make to invest repair dollars. Make the conversion now and the car will pay you back with years of continued joy.

Continue to cobble it together and you or a subsequent owner will no doubt prematurely junk it. What a shame. Money spent now could well pay off in the near future.

 

I would prefer going with the Bilstein. Either the air struts at 900.00 each or the active coil overs at 450.00 or so. The coil overs will require some modification to mount. They were an option on the R series.
I went with the RMT rebuilds because they are are 300.00 with round trip shipping. I HOPE these rebuilds are good for 10 years And a 100,000 miles. That is how long the originals held up.
I have heard that the coil overs sway more than the original air suspension. And a stiffer set of roll bars can correct for this.
Of course in a year I may have wished I had switched now.

 

If it were me, I would go with the Arnott coil/spring conversion.

 

Many diverging opinions...
I would go for the air spring unless you intend to keep the car for many more years/miles and want peace of mind.
Jeff, it's your money and your feelings...

 

Another vote for the air suspension

 

Who or what is RMT?

 

If we choose the conversion kit, and that is definitely still an "if", would Arnott or Strutmasters be the best choice? Both claim to bypass/disable suspension error codes.

 

Hello, for what it worth I too had to make that decision on my 2005 xjr. The Front air springs were leaking, plus one air springs was a Bilstein w/active suspension and the other was a Arnott. it took me quite a while to balance the pros and cons but I decided to keep it the way it was designed. I bought two new front OEM Bilsteins. The rears have never given me a problem. The ride in describable. Even with 20'' Sespang wheels. This Jag rides like its on air and yet ready for the track. Don't take this the wrong way but one shouldn't buy a Jaguar if you cant maintain it. Buy a Mustang.

 

Keeping it maintained as it was designed is actually the cheaper option, so the implication that I "can't maintain" it is unfair comment. This is essentially my wife's decision, this is her car. She is reading these posts to help her decide. I will spend the money to do whichever she chooses. My XJR gets pampered and she supports the boatloads of cash I have poured into this hobby because she likes Jaguars, too.

Basically her thinking is "I can either have the absolute certainty that I can drive an hour out of town for a school function with the kids while my husband is at work without worrying about a suspension failure - OR - I can enjoy the air suspension system that came on the car but never quite feel secure that I can trust it". I await her decision.

 

If peace of mind and continued good service is paramount then make the conversion .

I have been a member of this forum for over 8 years. The amount of tears and anguish over this air suspension design blunder during that time is astonishing. Were it not for the overall goodness of the car you would not be able to give one away. I would still have my XJR if the conversion had been available when I finally got a belly full of the drama and went to an XK. I still miss the car. You have an out I didn't have. Good luck.

 

I am installing another rebuild this weekend. They seem to be as good as the older Arnott that were rebuilds.
Call them for a price. I have been sending them a leaking shock for rebuild. They also sell rebuilt ones and them you can return the core for credit.

 

I do not need them right now.

Looked at their web site and prices appear pretty good.

I want to retain the CATS system when I need to replace shocks.

 

I just took her car for a ride to the auto parts store (instrument light bulbs for my XJR) to see how it drives. It's warm enough that the car stays up and drives nicely. It sank about a 1/2 inch while I was in the auto parts store though. I so seldom drive her car that I forget just how wonderful it rides.

It's ultimately up to her, but I may recommend trying one of those RMT rebuilds that Panelhead uses. It's only $300 after the core charge and with Summer coming I would expect less grief out of the air suspension system anyway. It would buy us at least another year, I would think. If we once again start to have suspension problems then we can either trade it or go for the conversion.

She still hasn't read all of your responses though. I will let her read them tonight and discuss options with her.

Thanks for the great input everyone...

 

Another vote for keeping the original system.

 

I was checking out the website. Anyone know if RMT offers sport vs comfort options?
Thanks!