Is is possible that the old desiccant pack absorbed so much moisture and freeze up in below freezing temperature and caused air block/flow? This resulted in compressor to take more time to pressurize the air system (and resulted in suspension fault warning).

I have two 2004 JX8. One has 35k miles and the other accumulated 70k miles. Both had suspension faults this week in cold weather (20F). I already replaced the piston ring for the higher mileage Jag last weekend. I did not replaced the desiccant. I bought the piston ring couple years ago and desiccant pack was not available. The suspension faulty was still On/off occasionally according to the lady of the house in freezing temperature..

I am pretty sure there are no air leak anywhere after extensive lines and fittings check. Height of suspension did not change after multiple measurements of parked car for last three days.

 

I don't know if old 'dead' desiccant does contribute to such faults but it's always seemed to me strange that replacement of the dessicant isn't in the service schedule.

It's true that when the system 'lets down' eg after you've had passengers, especially in the rear seats (and if they're heavy), it blows down back through the desiccant and that air being dry will tend to dry the desiccant. However if there are even slight, unnoticable, leaks in the system it will always over time draw in more air than it exhausts so the desiccant will never fully recycle.

And secondly there's good old gaseous diffusion. Even if the compressor never operates, and the system never exhausts, water vapour in the air will still diffuse through the air in the inlet pipe and get to the desiccant.

As to what the replacement period or milage ought to be I've no idea, except that it's probably just longer than the 'new car warrenty' period

 

The biggest thing to remember about our Jaguars is their just cars after all. Complex in comparison to many, but basic when you study how & why, Many times other parts will work just fine, being done by yourself. But the SNOB APPEAL, and keeping the dealer as the wizard, to fix it with genuine parts, must have it's appeal. But that's way out of my reach. I'll just continue to pick them up for pennies on the dollar, fix, drive, and enjoy them, after someone else takes the HUGE financial hit.

 

Well yes, moisture is usually the culprit and desiccant is the cure. Reach out to Don B. He's one of the moderators. He has a link to his project where he replaced the desiccant in his unit. I think he also has some desiccant left over and available for a fee.

 

The system is arranged to blow back some dry air from the reservoir to blow out the dryer after a longish trip. However, how effective this is is open to debate. FWIW, I had to have a new compressor on my last X350 in 2010, and 35k miles and that compressor was still on the car when I part-exed it for my X358 Sovereign late last year and 115k miles, and I never had a suspension fault after 2010. Plenty of other faults mind you !!

 

I'm interested to see if this could be the culprit on my car too. My car is an '08 with 73K miles on it. I was driving in 12 F degree weather and the Air Suspension Fault yellow light came on. It then switched to the red Failure light. I pulled over and let the car idle for 10 minutes and the heat of the engine warmed everything up and all was well again. This happened last year when the weather hit 12 degrees too. I'd like to tell my indy mechanic a possible fix for cold weather air suspension failures.

Has anyone else had this problem with cold weather? Is it a common complaint?

 

12F that's pretty cold!
Did you check if you had any leak on top of the air struts? It's a usual when cold if they're tired

 

Where is it located? How hard to replace?

 

No. I didn't check. I was on the road and just wanted to get inside and see if warming it up would take care of the problem. It makes sense that there may be a leak that only shows up in the most extreme of conditions.

If it is leaking, does that mean that replacement is the only fix? I understand that the air springs can not be re-built.

 

While you can't rebuild the air bellows (shocks) I believe all other parts are serviceable.

https://www.jaguarforums.com/forum/x...ration-174819/

Courtesy of Don B

 

Top of the air spring has an air line going into it with an olive seal. Don't over tighten. Some soapy water applied to it and you can see it bubbling. If it isn't bubbling, it's not leaking. But is only one of your shocks is low, don't assume it's the shock. Though they are prone to give out, the valve block could be failing or after condensation in the valve block or line can hinder proper operation. Read the link from Don I posted and you'll be an expert in no time.

 

It is usually the seal somewhere on top of the shock tower, inside and all around, more than the olive sealing.
This inside seal apparently wears upon time and temperature cycles in the engine bay and looses its elasticity so that under strong cold it does not tighten anymore and leaks.

If one shock leaks, all the front will sink as there is only one height sensor (since the 2004 MY I think).
If only one side sinks, it may be indeed an issue in the valve block.

If one shock is worn because of that top seal, you have to change the shock and purchase a new or a refurbished one.
You may still live with the used shock if the weather is not too cold, at the expense of much more work for the air compressor until the engine bay warms up.
If really too cold (below 0°C certainly, in my car at the end it was below 6°C), the seal will never get warm enough to seal and your air compressor will not be able to cope with the leak

 

You hit the target. I found air leak from one of the shock when tested using bubble method in extreme cold weather