The air spring system is both what makes the X350 brilliant (along with the aluminium body), but one of the most frequent complaints and why the unknowing will dump an otherwise great car after being terrified by the Jaguar dealer quote to fix. Even buying a complete replacement kit from internet vendors is not cheap, and as the cars become fully depreciated it can cause the ill informed owner to become despondent and act rashly. However, the air spring system actually is easy to access and not that hard to replace. It's just money but not a lot of frustration. Where it does become frustrating is when the replacement fails either instantly or prematurely. Here is a bit of research on what to buy, and seemingly safe vendors on the internet.

Bilstein original replacement air springs - These include the CATS
Miessler Automotive - Germany. List €1500. Their price €719 each including VAT https://www.air-suspension-shop.com/...front-BILSTEIN plus shipping (and they may deduct VAT for outside EU

Arnott air spring replacement new - These have a CATS bypass. Hard to know if it makes much difference - best to read forum reviews. These also are said to come with a lifetime warranty. AS-2888 is the front product number although this is a bit unclear as other numbers used as well.
Summit Racing is a trustworthy online seller https://www.summitracing.com/parts/ntt-as-2888 US$518 each plus shipping.

Arnott Coil replacement kit (all four). If you don't care about the air ride, Arnott has development an opt-out C-2290 . Remove the four air springs, the compressor and the tank in the boot/trunk. Replace with conventional springs and shocks. Read reviews for comments on performance.
Summit Racing https://www.summitracing.com/parts/n.../xj8/year/2004 US$1,326 for all four - shipping to New Zealand $265

https://aerosus.net/jaguar/xj-series.html appears to be a German company offering better prices €543.02 for a pair, but it until someone buys them and reports on quality, it is hard to say if they are an Aerosus brand made by them, or a knock off that won't last.

Compressor: The cheap option is Bag Piping Andy's rebuild kit for about £25 plus shipping. https://www.bagpipingandy.com/. It replaces the part that wears out but does not provide dry desiccant (look it up on the forum).
Summit Racing sells a new OEM https://www.summitracing.com/parts/ntt-p-2291 for US $476 plus shipping

Advice: Before buying anything however, invest in a soapy spray bottle and look for bubbles. If there are bubbles near the tank in the boot, it's a quick and cheap fix. If there are bubbles on the air spring (that you can see), unless it is from the tube, you are looking at replacement. As a consumable, you can either torture yourself with replacing one part at a time, stretching out performance until each part dies, or bite the bullet and replace everything at once. If that includes removing air springs that still work, put them back in the shipping boxes, mark them as still good and keep them as spares. They are easy to replace (especially the rears), so if one of your new ones blows out and you want to make a warranty claim, you don't have the car off the road while waiting.

Others: There are other vendors offering the same product at different prices. Amazon looked good until check out and the shipping was more than the air springs. When buying examine the return policy, who backs the warranty (the maker or the vendor), the shipping cost and the reputation. The only good deal is the one where the total cost includes purchase, shipping, one-time installation (no removal, return, replacement of defective parts) and longevity.

Who to avoid: Google RMT Air Springs or Rebuild Master Tech and read the reviews. They have a horrible attitude toward customer service and their rebuilt air springs tend to be poor value because if they leak you have to remove and replace. Ditto their compressor. If you live in the US, this is not as onerous as overseas where the cost of return shipping and the time delays are not worth it. If you are a victim of RMT, we did discover they don't care about what people write on forums, but did respond most aggressively when a posting was made on the Florida Better Business Bureau web page. As a forum, we need good vendors, so if you are a RMT victim keep posting BBB reviews to encourage them to up their game.

Some people have had trouble with CARID who sells RMT. Seems to be finger pointing with RMT saying it has to go back to CARID.

China? There are other manufacturers in the game, including Chinese and others that rebuild their shocks. If you buy these, please post your experience, including the vendor details, total price, etc.

Advice: As a consumable, new air springs are best budgeted for rather than try to save money on rebuilds. With the high pressure, a blow out is non-negotiable, it either works or the car is limp-home and hope nothing gets damaged. If you view your car as a cheap ride, buy the coil-overs. If you see your X350 as a future classic (and it is, given the aluminium body and classic style) buy Bilstein or Arnott air springs.

 

I have been very happy with my Arnott replacement shocks purchased a few years back

 

Ordered an arnott coil conversion 4 days ago. A few notes...

C2290 is obsolete.
C2745 is the same struts but now includes the electronic bypass module to suppress any errors from air suspension computer.

Best price was from "autopartskart" online store. Was ready to finalize an order when the back of my neck began to bristle. A quick search found abysmal reviews and a very poor BBB rating. I turned and ran.

Rock auto had nearly as good a price so i ordered there. Big mistake. Comforted by their ever-present advertising and name recognition I failed to recognize that they are 100% online with absolutely no customer assistance via phone or chat. Of course things went wrong and I was left deserted with no human to help. There was a problem processing payment whereby they took $1000 from my visa and showed no credit for the payment. Once I sorted that out, and placed the order a 2nd time they shipped me (stunningly fast) exactly half of my order and then marked it complete and took the full kit price from my card. With no one to speak to, this was a nightmare. Only thing good I can say-once I got them to recognize their error they again shipped with blazing speed. Despite the good price and fast shipping I would never order from RockAuto again due to the impossibility of getting any human help. Ill buy on Amazon or ebay.

 

if you have a 350 just use the s-type struts and a drill or swap to XK top mounts

arnott = 4x4 stance

 

I had a similar experience with Rockauto. Ordered the kit, got two struts for the price of four, what a deal. They would not simply send me the missing struts, I had to return what I had and make a new order. Finally got it corrected, but I love the coilovers. I was not going to dump thousands into a complete air overhaul, which is what it was going to take. That would have been over half what I paid for the car in the first place!

That said, I've used Rockauto for years, on many cars, and this was the only weirdness I've had with them.

 

My parts are here now, curious if your ride height ended up correct as other reviews suggest or too high as was reported earlier in this string?

 

Miessler sells their own X350 air springs; here are the rear springs for only 500 Euro. Doesn't say whether they have the CATS.
Says, "Rear air spring damper with CDC attenuation function (continuous damping control)",
and under Description says,
Does that mean the same as "CATS"? And has anyone used the Miessler air shocks?

ADDENDUM: The price on the Miesslers came down to 420 Euro in the minutes I was writing this post! Plus 85 € shipping from Germany.

 

When I 1st lowered my car off the lift, it sat like a 4x4 exactly as some had warned. A quick drive brought it down alot. Now, about 500 miles later it looks approximately correct. I do believe it was riding lower than spec before, and I do miss the way it looked. Ride is comparable to my modern Cadillacs but definitely not as nice as the air was. Hopefully more miles will soften it a bit more.

 

Here's good news about using Miessler air shocks to replace OEM Biltung shocks, from some Mercedes owners.
Although, since Miessler charges 419E for the Miessler shocks, and just 604E for the Biltung, the savings might not be worth the risk.

 

I've been checking https://www.miessler-automotive.com/ several times a day for the past few days, and both the Bilstein and the Miessler shocks are cycled through 2 different prices every day, one low and one high, different by about 100E. This might be to try to charge more to people in certain time zones. Check the website repeatedly until you get the low price.

 

I installed the MIessler (not Bilstein) air springs in the rear only. So far I'm not impressed. I have the impression that the ride isn't as smooth; but I can't claim to have any clear memory of what it was like before, other than that I never noticed it. I may have just become sensitized to the suspension by worrying about it for so long.

 

April 2022 Update: My left rear air shock blew out while the XJ6 was sitting unused for a month in the garage. I'm not sure if it is related, but I forgot to remove 150 kg of marble tiles from the boot (trunk). I began the search for a vendor with competitive pricing including competitive shipping.

I recently discovered FCP Euro in Connecticut USA when I need a part for my wife's Mercedes SLK. They offered competitive prices on brand name products and on international shipping. Promised 2 week delivery and it arrived on the promised day. So I emailed them and yes, they had the Arnott C2C41346 (AS-2891) air shock in stock.

Price US$588 plus $88.10 FedEx Shipping. I called Arnott Tech Support Toll Free Phone: 1.800.251.8993 (Local Phone: 1.321.868.3016) who confirmed ordering just one would not affect the system that has CATS on the other three. We'll see, I can always order another (ordering one at a time keeps the cost below the $1,000 Customs threshold)

At this point, FCP has become my go-to supplier for my Jag and our Mercedes cars.

If they had not carried the Arnott, I may have rolled the dice and tried Aerosus https://aerosus.net/jaguar/xj/xj-ser.../free-shipping €385 (US$418) plus €68 ($73) but so far have not heard from anyone who has actually tried them out.

If anyone has, please post the experience here.

 

Good lead. Cheaper than FCP Euro and it looks like Rock Auto ships direct (no need for myus.com which costs more)

FCP Euro
$588 AS-2889
$ 88 Shipping
?? Sales Tax (not collected by vendor, may not hit NZ$1,000 threshold
$676 Total (and could be more if 15% GST is charged)


RockAuto
$480 ($91 less)
$ 58 Shipping (or use https://www.myus.com/pricing/ at $126)
$ 81 Tax
$619 Total

As they have not yet shipped, I'm going to email FCP Euro and ask why they are so much more expensive.

 

I have over 200,000 on my 2005 XJ8 and it is still a daily driver. During the plandemic I was under financial strain and decided to go with RMT over Arnott for the rear air struts based solely on price. Now just 12 months later the RMT air struts are leaking and I am replacing with Arnott. The front original air struts went out years ago and replaced with Arnott and are still working fine. Do not buy RMT, the first order of two RMT rear air struts both failed as I installed them on the car.Lack of customer service was belligerent and difficult to work with. Finally got the owner on the phone and got them replaced with two that did work (for about 12 months). Can't say enough good about Arnott. Can't say enough bad about RMT. Save yourself the hassle and grief, go with Arnott.

 

Regarding RMT. Please go to https://www.bbb.org/us/fl/fort-laude...-0633-90369509 and post your experience. When enough people do so, Andrew Limpert, President, may get the message that he needs to up his game or get out of business.