Hello everyone,
This is my first request for advice/assistance, so I will try to be as detailed as possible.

2007 XJ8 with 67,000km. Bought car last year with just over 50,000km on it and have had no mechanical issues to speak of until today. I should point out that from day one of owning the car, the front suspension has always (every time) settled to a lower level immediately after turning off the engine. Car has alway risen evenly immediately after starting the engine and the amber warning light and message "air suspension fault" has never come on. Although the car was not driven in the winter, living in Canada we had some very cold days before the car was taken off the road and even in freezing conditions the warning message and light never came on (I have read in some post that cold appears to be an issue with the suspension). Can't hear any leaks and car is not sitting low(compared to what I am familiar with).

2 questions:

1. Any thoughts?

2. is it correct for the system to automatically release pressure after the engine is turned off?

Any input appreciated and thanks in advance.

AWGY

 

You should really re-post this in the X350 forum, as you will probably get a better response, however.........

1. Thoughts
How much lowering are we talking about here ? I have observed my car lowering slightly after traversing a rough car park. It was about 1-1.5 cms. No faults like you say, and all appears normal. Note that the lowering function is supposed to occur over 100mph, but I do wonder if there is more to the system than my 2004 technical notes say.
The system has a levelling function and will try to keep the car level at all times, so if you did have a slow leak from one spring unit, the car will gradually lower as this leaks away to keep the car level. However, is it ending up on the bumpstops or just lowering a bit ?

2. Release of compressed air
It is correct for the system to exhaust air after engine shutdown, to clear the water trap in the air compressor. BTW, these compressors don't last long, so if you have not already done so, be prepared to replace it some time, they're not outrageously expensive to buy and fit. Compressor failing normally brings up an air suspension fault and yellow light, with fault code C2303.

 

Fraser,

Thank you for the info. You bring up an interesting point in your first note; I had not given this any theought, but my drive way and also where I park at work is not level, in fact, the nose of the car is higher at the front because the ground is going up hill so to speak. Maybe this is the reason the car settles after parking and turning the engine off. The front does drop considerabley (gut feel, and eyballing it, but have not measured it) I would say an 12-25mm or half inch to an inch.

Many thanks.

 

Suspension levels by links attached to lower control arm and actuator. Pitch of your driveway should have no effect. Look forward to replacing suspension pump. Arnott is a good place to shop for one
http://www.arnottindustries.com/

 

Awgy,
Mine does exactly the same thing.
05 vdp with 48,000 miles (77 k kilos).
My garage floor is level so Georgekale might be right. The corners try to stay even with the car level spec.
Mine just settles about an inch and then comes back up just after starting the engine.
Once in awhile I hear the exhausting water trap. But not every time I turn off the car.
Arnott seems to have good compressors at good prices.

 

Thanks to you both for the advice and suggestions. Strange thing, I drove it home from work tonight and the warning message did not come on. Obviously something intermittent - oh joy! I will post any findings as the fault finding continues, and any further suggestions welcomed.

Andrew