Hi
The seller also put in new original compressor.
He just told me that the only thing he did not change was the air suspension valve block which sends the air to the 4 struts from the air tank.
Could this be a cause of the problem and if so how to fix and replace?

Thanks

 

Welcome to the site;
Its located in the trunk, under the spare tire
Lot of cheap after market replacements on ebay.
Should be an easy task for your first fix

 

My XJ8 also showed the air suspension fault. I read in several posts that this fault could have many different causes and that even when repairing or replacing a bad compressor makes the fault disappear, it would still be good to understand why the compressor got worn out. Following are the steps I followed to diagnose the problem and pin it down to the compressor:

• The DTC's I found were all and only C2303 Reservoir Plausibility Error, which is the result of air pressure measurements
• The car would never lower when standing still for a couple of days and the drive felt good.
• And now the interesting finding. When driving off in the morning, the fault would show in about 10-20 seconds after exceeding a speed of 40kph. I then discovered that lowering the speed to 30kph just before the error would show up otherwise prevented the fault from showing. After driving at 30kph for about 10 seconds before accelerating again and repeating this speed cycle 2-3 times, I could avoid the fault from showing up for the remainder of the trip.

I read that the ASM only activates the compressor at speeds above 40kph for NVH reasons. So, to me, the above confirms that the fault showed up because the pressure did not reach the required threshold within a certain period of time, indicating the compressor is no longer up to the job. By lowering the car's speed just before the ASM would set the C2303 DTC and show the fault on the display, I allowed the compressor to reach the required pressure in multiple attempts.

Confident that the problem was indeed the compressor, I ordered Bagpipingandy's kit to repair the compressor.

I hope my experience will help anyone trying to understand an Air Suspension Fault message.

Dennis

 

Thank you Dennis. Very interesting.
Did you perform the repair yourself?
Did the repair sort out the problem?
Perhaps even though the compressor in the car is a new original part...it may be faulty....

ill look into all the advice given on the forum and hopefully sort it.

 

Hi stg424,

The compressor is still the original one. I did do the repair myself and the new piston ring did fix the problem, at leas for now. 😄

In cases where a worn compressor is the result of another issues causing the compressor to work overtime, there would have been other symptoms, like the car loosing height after standing still for a while. Also with a leak, I assume the fault to show after driving for a while which in my case it never did.

 

I have experienced the same issues you are and have ordered that kit from eBay. Hope to have the issue resolved soon. Will update once the kit has been installed.

 

You guys doing that compressor kit, remember to check the dryer. You may need to replace the desiccant beads, and thoroughly clean any passages and valves you find in there. The bleed valve, especially, which is on the compressor body at the opposite end of the dryer from the actual compressor. If that valve is rusted and stuck, there is no venting of the air system when it's needed.

None of what you need for that is part of that kit, you only get the piston ring and some new bolts. If the desiccant is saturated you'll find water in that dryer cylinder, and there will be water in your entire system. Mine was so bad I basically gave up, as I had valves in the valve body not working, fittings leaking, and not only was my dryer saturated, it was actually full of water!

 

That's some good advice 9n the desiccant container

When I did my pump kit I put the desiccant unit in my air fryer oven on a really low temperature for couple hours so as not to melt it but using the fan forced heat to dry the desiccant do this to the dehumidifier breads in my collecter cars to stop em getting funky

My tank had no moisture in it I've also heard of using the microwave to dry the desiccant as well m

My pump looked really clean and corrosion free pretty dry over here on Australia although you wouldn't think so Adelaide and central Australia flooding at the moment

 

hello I have a Jaguar x350 2'7D and I have 1 problem with the suspension height, it started with the rear which was too high and the front at the correct height, then the front after a few days fell is also set to maximum height as in the rear... there is no fault code and I also lifted the car to check that there are no broken sensors and apparently they are intact . can someone help me to solve this problem please?

 

I found a lot of interesting and useful information in the “service training course NP04”

Dennis

 

This may be an inability to vent the system. That could be a stuck valve in the valve body under the trunk, or it could be the vent solenoid in the compressor. The only outlet for excess air is the vent solenoid in the compressor. A strut which needs to be lowered will have the valve in the valve body open its path to the compressor, and the compressor's solenoid will be opened, two separate valves that have to both work, and work together. Corrosion could have them stuck, unable to open. Since it's all wheels stuck high, I would look at the compressor. That vent solenoid is not easy to access, as you have to remove the compressor from the car and disassemble it, remove the dryer cylinder (which will be messy because of the desiccant beads you'll have to catch in a pan,) and once you're that far, you'll probably find a lot of rusty, corroded passages that will need serious cleaning.

 

thanks
Is inside the compressor ? So is better to change compressor ?

 

Yes, the vent solenoid is on the compressor. Changing the compressor is a good starting point, but expensive, with no guaranty of success. I would remove and disassemble it first, see how bad it is, and install the bagpipe andy kit while it's out. If the corrosion is simply too much to clean out successfully, then replace it.

You may still have failures downstream of the compressor, which, of course, is the entire system... Mine had so mush water and rust in the compressor I didn't even try to save the air system and went with coilovers, because I knew that water would be throughout all components.

 

Beautiful. I am reading this 11 years after it was posted!

 

It must be true then.

Poor OP had a fault when only 4 years old.

 

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Ced027, I read the service training course from beginning to end. I learned a great deal about the suspension system AND enough, I think, to be able to diagnose my problem! But I always welcome the wisdom of the forum. So I will know by noon tomorrow whether I have a leaking system. I am already pretty sure my compressor needs a kit thanks to timing the duty cycle and the suspension fault indicator. This is all good!

However, this rigid ride has me confused. I don’t find much about that. Some describe it as Transportation Mode. How did I get into that? How do I fix it? Still thinking through it and working to resolve. Thanks for your attention and help!

 

can you help me

 

I would follow the suggestion from whooshes and inspect the vent solenoid on the compressor.
If you want to diagnose the problem further, get an OBD reader and check the controller for the air suspension (ASM)

 

Dennis, I don't think an OBD reader will be able to read this. The ASM is unique to Jaguar and will need a reader with the JLR software to read these faults.