Hello,



Thank you for this post and the attachments.

very useful and detailed.

I am an owner of a 2007 xj8, equiped with this air suspension system. This car mileage is 30 000 only, so very low.. the car is in very good condition.

I live in northern Scotland, so quite cold this time !



I bought this car last year, and I have noticed that after at least 24 to 48 hrs, the front side level dampers (both) goes down to the lowest height. Complete bleeding off ..?

however, the rear ones, remains at their normal height.



when I open my car, pressing the key button to unlock the door, I hear and observe a level adjustement on the rear ones (maybe to compensate with the front dampers depressurization ??, switching the another mode as per the manual)

The first obvious approach would be to think about a leakage.



however, when I turn on the engine, roughly, one or two times out of three, the compressor starts up and the front level directly rises up.

but !! Sometimes, even if the level is low in the front (no error message in the dashboard), When I start up the engine, the compressor does not start up. I wait 10-20 mins, still nothing happens.

then, I start to drive a bit to pass the threshold of 40km/h, and then, once parked back, the compressor starts.

it is very inadvertent and random behaviour.





could you advise me on What other checks can I do ?



I went to Jaguar today, for a servicing. They kept the car 24hrs, not enough time to have the phenomenon of lowering down the car.

they did not find any fault/defect in their system ....



Would that be the manifold block valve which is in fault in the reservoir line ?

Lets go troubleshooting !



Thank you all for your help.



Regards

Antoine

 

Hello Antoine,

Welcome to the Jaguar Forums! It's great to have you with us.

I have moved your post to start your own thread.

The most likely cause of your symptoms is a leak in one or both front air spring top seals. The top seals are large rubber moldings that wrap around the aluminum upper plates in the assembly and seal the top of the air bladder. As the rubber seals harden, when the aluminum plates contract in cold temperatures, small leaks open between the seal and plate. Since both front air springs are inflated and deflated together, when one leaks, both units sink.

You can test for a top seal leak by spritzing soapy water into the recess in the tops of the front air spring/damper units, taking care not to wet the electrical connector for the ECATS adaptive damping. Bubbles indicate a leak.

Other potential leak points are the air hose fittings, and the O-rings that seal the pressure-retention valves to the air springs.

Please visit the New Member Area - Intro a MUST and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.

Cheers,

Don

 

Hello DON,

I have carried out the test. No leak observed on my side.
The video link here.
https://www.dropbox.com/sh/dek84pzrv...WMKofKyua?dl=0
what do you think ?

Cheers
Antoine

 

I am having the same exact problem but with my rear shocks, I have a 2008 x358 and did not have a problem with the air ride all summer until the cold temps came we are having in Colorado right now. The rear of the car will sag overnight in the cold weather, and when running / driving I can hear air leaking out of the rear right shock, but after some driving it goes away and holds air as it should. It seems to be an intermittent problem.

I suspect the top rubber seal you described is what is leaking. Can these be replaced or does the entire shock need to be replaced? The previous owner installed front Arnot air shocks and the front holds pressure just fine in the cold temps.

Thanks for the info !

 

Unfortunately, the top seals are not replaceable. There is no known source for the seals, and the air spring housings are crimped together in a manner that would require cutting them off or otherwise damaging the housing in order to remove them. Your options are to replace the air spring/damper units as an axle pair or to convert all four units to coilovers.

Cheers,

Don

 

Thank you Don, that is what I figured, ouch. Hopefully as the weather gets warmer I won't have the problem and can keep driving leak free

 

Hello Don,

after the spray bubble leak test, which was not fully obvious and conclusive to my observation on the videos, I am still investigating.

I monitor the car front level on faily basis, every 2 hours !
Yesterday, I saw again, a 1 cm drop in front side level.
I opened my car with the key, the rear dampers have been automatically adjusted.
then, I went on the front passenger side of the car, put some manual weight on the wing side, then, the car suddenly reacted and rose up !!

is that could be a height sensor issue ??

Cheers
antoine

 

Antoine,

I'm not convinced that your car is doing anything that unusual. My car typically sinks slowly (mostly in the front) over a few days. It did this before I replaced the front shocks (with OEM Bilsteins) and it still does it with the new shocks. It also does many other strange leveling functions such as you describe, depending where it's parked and what the position of each wheel is and the outside temperature. After 2 years of observing this, I still can't explain exactly what it's doing but it never gives errors and it's always very level when underway and when first parked. If your car rides level during use, and there are no errors on the dash and your dealer saw no codes I would forget about it. When there is something really wrong you will get fault codes.

Best Regards
Jeff Colquhoun

 

It is normal for the ASM to wake up from time to time and allow air pressure to vent via the exhaust valve to lower high corners in an attempt to bring the vehicle closer to level. The air compressor will never run unless the engine is also running, so the only way the ASM can level the vehicle while the engine is off is by letting air out of the high corners. The air suspension section of the dealer training manual clearly explains this.

What is not normal is for any air spring to sink to its bump stop. This indicates that air is escaping somewhere other than through the exhaust valve, bypassing control of the ASM.

You can download the air suspension/ECATS section of the dealer training manual and several other documents in this post:

Air Suspension & ECATS System Summary: Components & Operation

Cheers,

Don

 

Hello Don and Jeff,

well noted.
thank you again for all your support, I will keep monitoring any leakage.

on the front dampers, no leak on the top ... neither the air supply line nor the the damper seal.
it would be a very tiny one.

take care
cheers
Antoine Joyeuse

 

Just a note on the compressor coming on only with motor running. I had key on, without motor running, put in neutral and pushed the car out of my garage, down a slight slope. When braked to a stop at the bottom the compressor came on and the car level adjusted.

 

Did you do the spritz test when everything was cold? Ambient and engine would have to be at the temperature where the leak occurs.

 

Folks,

I have been keeping observing my car.
after one or few days, the front level is droping.
when I open my car (press the unlock button on the remote key), there is an automatic adjustment done on the rear side. i can hear and see it, its quite reactive.

the level rises on the rear but not in the Front.
then, I turn on the engine, nothing happens.
i try then to make some pushes on the front aisles, and then, the compressor starts !

last time, even the car parked, having just unlocked it as described previously, pushing down on one of the aisle helped for the car to rise-up using the air stored in the reservoir.

i have already done all leaks checks on the front dampers. No bubbles at all.
I assume, I have a height sensor sensitivity issue on the front ones (just one or both).

could you advise on what I can do ?
these sensors can be recalibrated, checked ?
any offset in the readings ?

many thanks again for all your support

cheers
Antoine

 

I do look forward to an informed answer, as my 2004 XJ6 has the same problem. The prior owner replaced the front air shocks and it made no difference. It pumps up in 20 seconds, so I now do the drill of turning the car on and wait.

A comprehensive shade-tree mechanic troubleshooting would be appreciated. Or for the person wanting to do a restoration (fix everything, even if not broken), what should be replaced?

 

Is your car on level ground? It tries to keep the car as level as possible and may jack up or drop one end or corner to maintain true level inside the car.

 

Just to clarify again, the only method the ASM uses to level the car in Sleep Mode is to lower one or more corners. It will not use reservoir pressure to raise any corner, nor will the compressor run to replenish the pressure. Here's the section from the manual:



Antoine,

When you press down on the front end, you are causing the height sensor to move downward, which is apparently prompting the ASM to raise the front end. Your front suspension is definitely losing air somewhere. You may have other issues as well, such as an issue with the height sensor, its electrical connector, poke yoke arm, etc.

Here's the link to my scan of the air suspension section of the Dealer Training Manual. It really pays to study this for an understanding of normal and abnormal system operation as you diagnose the cause of system misbehaviors.

X350 Air Suspension Manual

P.S. The hand-written notes in my copy of the manual, such as the "30" written in the section above, were made by the Jaguar dealership technician who used the manual during factory training, so I trust that these notes were accurate as of the time of the X350 new model introduction.

Cheers,

Don

 

Don I did not mention anything about it being in sleep mode. When parking on uneven ground it will adjust, this does not seem to be an instantaneous reaction. It also adjusts with changes in loading. With the engine not running and loading the trunk the car will rise to normal height as the weight increases. There is also a statement that the compressor will not run until certain criteria are met. However it does run without those criteria being met. Mine has come on, to raise the vehicle, when the engine could not start due to a module being disconnected. In that case it had been rolled to another position on the driveway. which was a different slope than where it started from. It levelled when it was stopped, using the compressor to supplement the reservoir.

 

Hi Edward,

I believe you are describing behaviors in Preliminary Mode (just after the doors are unlocked and the system awakens) or Post Mode (the 30 minute period after the engine is shut off). After 30 minutes, the system enters Sleep Mode, and this must be the mode during which Antoine's suspension is lowering, since he states that he has been observing it as it sits for one or two days.

I don't recall any indication in the documentation that the compressor will ever run while the vehicle is sitting for extended periods in Sleep Mode. If it did, you would think the battery would soon be depleted, since the compressor draws significant current (its circuit is protected by a 40A fuse).

Cheers,

Don

 

Yes,that all fits Don. I have been lucky so far and not had the sleep mode problems. I do find however that my car has not read the manual and sometimes does things it is not supposed to do!

 

Same for mine.
When she sits a bit low during cold and not driven for too long, the air compressor sometimes starts and runs for 20 seconds only to replenish the tank, even when she is not yet moved.