Of my xj8 4.2 there is a warning in the dashboard that the suspension at the front is not working.
in a few weeks i am going tho my jaguar garage (in the netherlands) to investigate the problem
i understand that each front suspension of the original jaguar make is very expensive.
can anyone inform me wether there are equivalent items on the market?

 

Air suspension is one of the most common discussion points on this site, with every possible brand and type of suspension having been discussed to an exhaustive level at one time or other.
Suggest you do some basic thread searches to see what other members have discovered over the years with each option.

You can replace with just a basic coil over suspension module with no air or CATS system.
You can replace with aftermarket air suspension, but most do not support CATS.
Or you can go for original to have air and CATS.

 

Does the dash message actually specify front? All I've ever seen is "Air Suspension Fault," or even "Car Too Low," and you have to get a code reader to determine what the fault actually is. Could be the compressor, height sensors, misbehavior of the solenoid valve (perhaps stuck with rust,) or air leaks just about anywhere in the system.

The air system is long past its design lifetime, especially if it hasn't been maintained, like a periodic replacement of the desiccant beads in the compressor (which is not actually a called-out service item.) Water getting into the system is a Very Bad Thing, as it corrodes everything, and there is no facility for removing it. If you're lucky, everything is working OK except a height sensor is bad for some reason or another.

Original OEM Bilstein air struts are VERY expensive. Several companies make aftermarket air struts, almost none of which support the CATS soft/firm electronic valving, although some (notably Arnott) provide a module with their struts to disable the CATS warning messages that result from the strut change. Most of those same companies also make steel-spring coilover replacement struts, with the same caveat about no having CATS any more. I have the Arnott coilover system, with the module to disable the CATS messages, and I couldn't be happier. It was FAR less expensive than fixing the air system! others will tell you that no coilover system compares even remotely with a working air system as far as ride comfort is concerned, but I wouldn't know, because mine was always excessively harsh until I changed it out. i've never been in an X350 with a working air system.

 

All 4 Jaguar brand air suspension struts replaced cost @ $6,800 last year. Failed at 49k. Some swear the jag air susp. is one reason the xj8 ride so nice.

 

WABCO-Bilstein system might be more accurate, as the X350 is but one of about a dozen different makes and their brands that used it - including essentially ALL the major German makers and their bought-up 'brands', for example.

The "improvement' a properly working system brings vs coilovers is simple enough.

CATS adjusts to load mostly, "road" dynamics only somewhat.

So it isn't just a fine ride with driver alone, or driver plus blanket-sharer, or driver plus blanket-sharer and infant through fully grown byproducts.

It works well with all combinations of seats filled, fuel aboard, and luggage load.

And without need of human intervention to call for the adjustment.

Now.. if one wanted all that and self-repairing, even auto-reproducing?

Yah think metal-Jaguars are burdensome, d'you ken the care and feeding of flesh and bone Elephants?

 

————————————————
(geez, is this the way to reply? I don’t see an empty box.)
anyway, Wild post, don’t understand all of it, but reads creative! The last line pertains to caring for children? (I dodged offspring… AND elephants!
yeah, don’t know if I personally woulda replace w/same air suspension at that cost. But, seller did. If it last to 100k that be great. Guy DP had other front end work too mainly tie rods & alignment. Almost $9-$10k just on front end. Makes me a lil nervous re: repairs. But, better replaced BEFORE I bought. Here’s some repair prices seller made within last 16 months in case ppl are interested: Wiper trans. motor replaced, $800, (Just to move wipers.), front tie rods $1,075, front pads, serp. belt, new coolant reservoir, fluid flush, (trans. leaking) pan kit, filter, fluid flush, plug, seal $1,070,

so, the CATS air suspension automatically adjusts to the road, speed conditions? Like on highway, lowers car to make more aerodynamic? I’m still understanding how it makes the ride feel. Sometimes, it feels boaty, drifty, sorta floating left, right, back, front? Pretty normal for luxury cars. I think I feel the makeup of the road more than the xk8. The xk is too busy flying… hugging roads, corners.
Also, I have to say that having the xj8 a few days… I like my ‘04 xk8 conv, that much more. The engine in both always brings a smile to the driver. The xk’s tightness, firm grip spoils owners. Tho, the xj8 is also quick, smooth. Sedan vs Sport can’t expect to be the same.
i just hope that our Jaguars treat us well, keep our wallet (cryptocurrency?) out of our mechanics lair.
As always, thnx to the many owners here who are a lot smarter than me. Your care & wisdom is appreciated by more people than you realize.
Cheers!
Cino61

 

I think the statement he made that CATS adjust to load mostly, road conditions only somewhat, is completely wrong. CATS is nothing but soft/hard damping, and selects hard when driving conditions meet criteria in the controller, according to sensors for speed and steering input. It could care less about load.

Load is compensated for by pressurizing or venting individual struts. It is NOT "active suspension," reacting to driving conditions, it is simply keeping the car level under static conditions. You throw a ton of luggage in the trunk and/or a couple of adults in the back seat, the car will level up so it doesn't sag in the back. The ONLY action the air suspension takes according to driving conditions is to slightly lower the car at very high speed, a speed you can only reach legally on the Autobahn, and it drops the car a few millimeters to reduce underbody airflow and thus drag.

The CATS system is "active," in the sense it stiffens the shock valves if the car is being "thrown around," and keeps the damping soft for normal driving. That is all it does, and this "all-it-does" is the reason for CATS not being a priority in the aftermarket. Most drivers won't even know it's being done, unless it fails and stays hard. There is no action from CATS according to load. CATS is not part of the air system at all, it's simply shock valving.

 

Well the use of the term 'CATS' (because that is wot shows up on the error screen) was surely lazy on my part - so "wrong" is a true observation, yes:

- The Air STRUTS don't care about dynamics of rough roads or smooth.

- The "CATS" damper modulators don't care about loads nor leveling.

They are mounted 'coaxially' into one unit, but are otherwise two independent workers with different jobs to do who just happen to live in the same hoorhouse.



Agreed.
"Funny you should mention 'Autobahn'. " Wonder if they call that feature the "Bernd Rosemeyer debacle risk reducer"? (28 January, 1938)
There is one other 'tell'. It CHANGES the way the vehicle responds, and at a time a driver may not WANT it to do..

VERY bad thing to have going on when an experienced driver is pushing the limits - not uncommonly over roads I been 'married to' since the dawn of the 1960's, (USA) end of the 1980's (UK & Europe).

I'm not accustomed to having it. I am now delighted to no longer have that fool 'CATS" system interfering with stability - or trying to out-guess me - on the X350!

Hard damping, soft damping, near-as-dammit NO damping?

I'm good with any of it.

MOST of us are after long years of 'many vehicle' exposure, little or no choice about that OR the route and roads. We Just F(irmly) Deal With That.

So long as I - not the motorcar - can adapt to wotever it IS I find in-place, any vehicle - then trust it will REMAIN good. bad, indifferent......at least for the full course of any given journey- that's all the 'stability' wanted..

Some other hour, day, week, month, year.... decade.. some other vehicle, some other situation for the HUMAN to adapt to?

'So far..' we humans are still better at such adaptations than any AFFORDABLE electronics, after all.

 

I replaced the air springs on my 04 XJR many years ago with the Motorcars LTD Blackdog coilovers. Absolutely excellent. Many years and miles of service until I sold it this year. Not a fan of Arnott, but maybe they've improved. In any event, on my X358, I seriously doubt I'd replace an air shock with OE. Might try another brand air shock or just go coilovers again. Hopefully, with some luck I won't have to deal with it as I do like the air suspension on the X358. That said, other than self leveling which rarely applies to me, I don't know that it's any better than good coilovers.