I have read all the previous posts and threads regarding air suspension issues. I have found no deferential diagnosis that can identify this sometime intermittent problem. A complete failure is easier to identify.

1. Low ride on a corner, front or rear. An obvious problem can be identified by a audible or visually identifiable air leak around the top of or coming from one of the corners. This would indicate the air bladder or some other part of the strut had failed allowing the air to leak out.

The solution is the replace the leaking strut or replace everything with conventional "coil spring over shock-absorb-er" struts. All available from Arnots.

2. Low ride all the around. No air compressor sound audible or the compressor runs and times out not raising the car with no air venting from air struts.

The compressor is burned out and needs to be replaced or is not compressing air fast enough and needs to be rebuilt with a new piston from the Bagpiper" or a new compressor from Arnots.

My issue is transient and like many is related to this extremely cold weather of 20 F to -10 F in Polar Vortex Ground Zero Wisconsin. I have four transient conditions. Checked for stored codes with my Innova 3100 scanner and find none, even thou the Air Suspension Fault appeared on the dash display. Possibly this type of scanner can't read these type of codes.

1. Suspension works normally for days as the temperatures swing between 37 F and 20 F

2. The front end drops over night after being in slushy then sub-zero F conditions then in my unheated attached garage. Start the car the compressor runs raises the car and shuts off. Car drives normal. If doesn't raise enough, take to the car wash and now works properly.

3. The rear drops while driving in extremely cold weather. Shut the car car restart, start driving and rear raises to normal level.

4. The front and rear are both high simultaneously and will not lower after sitting over night in my unheated garage.

It would appear, given this last condition, that I obliviously don't have air leaking from a strut or the actual supply of air that's deficient. there must be a third component that's effected by temperature that I can't determine.

There are many horror stories posted of replacing compressors or struts as individuals or mechanics throw parts at the problem and not determining a root cause.

This XJ VDP replaced my 1998 Lincoln Continental which also had rear air ride and never gave me a problem after 14 years and 110K miles.

This simple solution is to scrap this and install conventional suspension or move to Florida.

I found the following information which I did not find in any previous posts:

Ford/Lincoln Air Suspension- TOWN CAR
Author: Eddie Spinks of American Air Suspension

The rear of my car is too high and the "Check Suspension" light comes on after approx. 45 seconds

Excessive moisture is a pretty common problem for Town Car and Mark VIII(8) owners. Excessive moisture in an air suspension system is extremely hard on compressors. One of the first things to go on a compressor is the vent solenoid. The reason for this is that whenever the vehicle vents(lowers), moisture is blown through the compressor, through the head of the compressor, through the vent solenoid, and then to the atmosphere. In a nutshell, the compressor is taking a bath every time the car vents.

WHAT IS THE VENT SOLENOID?

The vent solenoid is basically just a little metal piston that goes up and down with a coil wrapped around it. When its subjected to moisture frequently, rust and corrosion will soon begin and get worse as time goes on. When the rust & corrosion gets bad enough, the coil won't be strong enough to move the metal piston any longer and becomes inoperative either in the open or closed position.

If it freezes up in the closed position, the vehicle cannot vent the air in the air springs like the module wants it to. The result is a higher than normal rear height and a check suspension light on.

The module is programmed to try and vent the air out of the air springs within 45 seconds, but if it doesn't accomplish this goal, it will assume theres a problem, turn the light on and shut the system down. This is called the vent timeout. The system won't try to make any more adjustments until either the "ignition" is turned off, then back on, or the "suspension switch" is turned off then back on. If one of these things are done, it will then try to vent again until either it reaches the desired height or the 45 second timeout turns the system off, which ever comes first.

If it freezes up in the open position, no matter how much the compressor tries to pump, it cannot build much more than 20 p.s.i., because the compressor is simply allowing the air an easy way out instead of making it build pressure and raise the rear of the car. With this problem, if the air springs have more pressure than the compressor can put in, the springs will win the pressure battle and the air in the air springs will actually blow through the compressor and vent, which makes the rear of the car go down. You will also get a "check suspension" light on after 90 seconds or so because the module has reached its limit to raise the car.

WHAT IS NORMALLY DONE?

What is commonly done, is just replace the compressor. This will get the vehicle operating normally....temporarily. Because nothing was ever done about the moisture, it will soon overwhelm the new dryer and damage the replacement compressor.

THIS WILL HAPPEN WHETHER YOU REPLACE THE COMPRESSOR WITH A NEW OR REMAN!

To cure the root cause of the problem, you must remove the moisture from the system or protect the compressor from the moisture. The Ford shop manual says to replace both air springs, replace the compressor/dryer assembly and replace all the lines in the system. After working in Ford/Lincoln dealerships for over 15 years, I know for a fact, that this is rarely ever done. In other words, most of the techs working on the air ride systems these days aren't aware, or maybe don't even care about the moisture problem and they WILL NOT do anything about it.

WHAT SHOULD BE DONE

Since the problem is moisture, your goal is to either do what the shop manual says to do and replace EVERYTHING in the system including all the air lines, to the tune of $1,500+, OR, just replace the compressor/dryer assembly and then re-replace the dryer several times within a 6 month period. Then once a year after that. No, you wouldn't want to have to pay $300+ for a "new Ford" compressor/dryer, then turn around and spend $100+ each time for a dryer. Go HERE to get the parts for a fraction of the cost of new with a better warranty!


After reading this, it would seem that Eddie's explanation makes sense unless there is no air dryer or valve that freezes up and allows air to all escape or holds it in the Jaguar system. When I was at the Jaguar Drivers Experience tent this fall they had a display touting basically the weight savings that this suspension system gave this vintage XJ over conventional.

I would enjoy some fresh comments regarding Eddie's theory or your solutions. I just returned from snow blowing in 17 F and -12 F wind chill.

 

There is a moisture trap in the compressor. This is regenerated after a run when the system blows air back through the trap to blow the moisture out. However, I suspect in very cold conditions this action cannot occur as the moisture is now ice and cannot be blown out. In my personal view, Jaguar (actually Ford !!), rushed into air suspension without thinking through the consequences in a place like the USA, with its sometimes bitingly cold winters. The other thing is that you might have a slight leak somewhere, but will have to go around testing where when Wisconsin warms up a bit !

 

>3. The rear drops while driving in extremely cold weather. Shut the car car >restart, start driving and rear raises to normal level.

>4. The front and rear are both high simultaneously and will not lower after >sitting over night in my unheated garage.


Ed,

I found your post very interesting, having just rebuilt the air suspension compressor on our '04 XJR. I replaced the piston ring and desiccant and cleaned rust and mineral stains out of the cylinder head check valve, but now I wish I had also opened the exhaust (vent) valve and pressure relief valve to see if they also needed to be cleaned.

The curious thing about your symptoms and the possibility of a stuck exhaust valve is that you would think your car would either always sit too high or never achieve proper height, depending on whether the exhaust valve was stuck closed or open, respectively. I suppose it is possible that if the valve components are corroded, they sometimes stick closed, sometimes open.

After rebuilding the compressor on our car, it definitely raises more quickly on startup. But in cold temps (mid-30s or colder) the suspension lowers and can take several cycles of the compressor to refill. Under these conditions, I can hear and feel air leaking from the top of the front right shock (not at the air hose fitting). I have read that some Ford air shocks have a replaceable "Spring Cap," which apparently seals the top end of the air spring, but I have thus far not been able to find a source for replacement parts for the Bilstein air shocks used on the X350.

As to whether Jaguar rushed into the air suspension business, I don't think we can blame Jaguar, since Wabco ECAS system used in the X350 is also used by Audi, BMW, GM, Land Rover, Mercedes, Porsche and VW. The air compressor used in all those systems is essentially the same part with minor differences in mounting brackets, temperature sensor, and exhaust valve operation. I think I read that Wabco has sold 35 million air compressors, so it is established technology. The piston ring made by Andy Fulton (bagpipingandy.com) fits the compressors used in all those brands of vehicles.

And Bilstein, of course, makes air shocks for Audi, Mercedes and other luxury automakers.

Below are links I took of the air suspension rebuild process on our '04.

I hope others will be able to offer additional information as we all try to sort out these fussy air suspensions.

Cheers,

Don

Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page
Welcome to Jag-lovers - Members Photo Viewing Page

 

Ed,

A few more thoughts. First, I have an Innova 3130b scanner and the only code I've been able to read on our X350 is the apparently innocuous P1111. I suspect our Innova scanners can read at least some of the "P" or Powertrain codes on the X350, but not the "C" or Chassis codes, which would include suspension faults. I tried choosing the "Ford" manufacturers codes on my scanner but that did not result in any additional DTC discoveries. I tried this because I read on one of the forums that an owner had discovered his scanner could access the Jaguar DTCs when he set the scanner to read Ford vehicles. I have ordered a couple of the inexpensive Jaguar-specific scanning systems (clones of JLR IDS SDD) for use with a Windows XP Pro laptop and will see if one of those systems can find additional DTCs on our car.

Another thought occurred to me: When I turn our car off and step out of the driver's side door (LHD car), I can hear the exhaust valve or vent solenoid releasing air from the compressor at the front left corner. Whether this is to relieve excess pressure to level the car, or is part of the system's desiccant reactivation procedure, I do not know. But it may be a way to tell if your exhaust valve is at least able to open and re-close to some degree.

Cheers,

Don

 

Don,


If it wasn't 0 F this morning, I would take the compressor out today. I definitely feel that there is a component in the compressor hanging up causing these radical issues. I am sure that there may be a slight leaking in strut that will develop or is occurring, however there is a valve, some component hung or clogging/icing up somewhere in the pump system.

I am going to rebuild the compressor unit per your illustrations including the check valve. Where did you source the desiccants and the piston ring? I intend to rebuild the compressor as soon as possible.


Thanks for the great work. If we can solve this, it would really help a lot of Jaguar enthusiasts.

 

Ed,

I sourced the desiccants from Sorbent Systems, their item 997AG01, 4 oz of 2-4mm molecular sieve beads; and McMaster-Carr, item 1523T64, 5"X5" molecular sieve desiccant packets (with approximately 1/16" beads). PM me your address and I'll send you some of my leftover desiccant which may be enough to do your entire dryer. If I did it again, I would order 1 lb each of 1/8" beads and 1/16" beads of 4A molecular sieve, which wouldn't have cost much more than what I ordered but might have saved the time I spent sorting beads. I did find at least one supplier that offered 1 lb quantities of 1/8" and 1/16" beads - I'd have to go back and look at my notes to identify the company.

I purchased the new piston ring from Andy Fulton, www.bagpipingandy.com. His website will redirect you to his ebay listings to purchase his rebuild kit. It cost me about U.S. $48 with shipping to Tennessee from the U.K. The desiccant cost me a little over $50, so I rebuilt the compressor and air dryer for just over $100, far less than the cost of any replacement compressor option (which would be a dreadful waste of both money and perfectly good compressor hardware).

I agree that if we get enough "can do" minds on this we can conquer all these air suspension issues. I'm not ready to accept that it takes a four-figure solution to keep the stock suspension functioning properly or to replace it with standard coil-overs.

When you rebuild your compressor, I would suggest opening up both the exhaust valve (vent solenoid) and pressure relief valve to clean them out. In retrospect, I should have done that too. On the bagpipingandy website he has instructions for rebuilding the compressors on several models of vehicle, and in at least one of them he shows the pressure relief valve opened up.

Please keep us informed!

Cheers,

Don

 

I was in Memphis 3 weekends ago and Nashville about 2 months ago. It was brutally cold when I was in Memphis/Collierville.

Juke

 

Interesting post and thank you. I had my Compressor out and purchased Andy's ring. I noticed how quick it rose after, but didn't realize the other items I should have checked or replaced. I guess I will order these desiccant's and replace. I cleaned the rust from the interior of the compressor but not the other items mentioned like check valves. My only thought or concern would be that even if I go in and clean all the parts on your awesome step by steps and replace the desiccants should I not be concerned with the 90,000 miles of service the compressor has already given the Jag. So the question is to replace or to rebuild what I can? Is there any other part that could fail inside? Thanks

 

Hi Juke,

Yes, it has been a colder winter than usual in Tennessee, but oddly much of the snow has gone south of us, across northern Alabama and Georgia. I don't suppose you've had any snow as far south as Shreveport?

Cheers,

Don

 

Hi Motorfreak72,

If I were you I wouldn't hurry to work on your compressor again until it malfunctions. The desiccant is partially reactivated on a regular basis by design of the system. I just thought it was a good time for a fresh start, since the desiccant is only partially reactivated in normal use, and I figured the system could use some extra drying at this point in its life (80,000 miles).

Regarding other things in the compressor that can fail, they would include the electric motor, piston rod/crankshaft bearing or bushing, exhaust valve and pressure relief valve. These components appear to be quite robust, but they could be subject to corrosion due to moisture in the air pumped through the compressor. If you have another reason to remove the compressor again, it would be prudent to take it apart more completely and clean all the rust and mineral deposits. But unless the compressor mishbehaves I'd just recommend that you enjoy your beautiful Jaguar.

One modification I am considering to our air suspension system is the addition of a water trap, perhaps one that can be evacuated at the press of a button. But first I need to figure out the cold temperature leakage.

Cheers,

Don

 

The problem I have been fighting now with the suspension is the amber light showing Air Suspension Fault. The compressor sounds alot louder than it used to. Although it is still pumping air to the tank in the boot it appears to shut off before the 3 minutes of pumping air that ive read about making me think shes got issues. Here's why I want to go back in to the compressor. After the car has been sitting overnight she is sitting low(inside the garage).There are times when I unlock the car she pops right up...than there are times when I have to start the car a few times after the compressor times out. Those mornings when im restarting the air compressor is when I see a red light (Too Low indicated). I live in Florida and am not dealing with the cold temps right now so thats out. I have searched endless for leaks, I have replaced every O-ring in the system, I have gone thru enough soapy water that my wife thinks I should start doing the dishes by hand, I have replaced all four shocks with Arnotts and replaced the piston ring. The car had blown air suspension for abit so my thought was overworked compressor. Than I also wondered about the level sensors. Needless to say between this and a vacuum leak on banks 1 and 2( waiting for parts) its starting to get to me alittle. Does any of this sound familiar to anyone? Any thoughts on what I should be looking at? Or do I give in and hope the techs at my local Jaguar know how to test the suspension with there scanner. Id kill for my own scanner right now.

 

It does sound as though your exhaust valve could be malfunctioning, so it might be worth pulling the compressor to have a look. It might be even more expedient to have the Jaguar dealer scan your car for stored codes, which may help pinpoint the source of your problems. Another component that is known to cause problems is the valve block (in the trunk next to the air reservoir tank).

 

hi this is still symptoms of a tired compressor, did you buy and fit the piston ring compressor kit from me? (bagpipingandy) There are a few cheaper copies of my kit out there now which DO NOT work well at all, I have tested them with poor results, let me know if you purchased it from me or someone else so we can help what could be wrong

As Don B says earlier, these compressors are well made and altough other parts can fail, it is mostly (not always) the piston ring which need changing, i would not jump into a full strip just yet,

best regards

Andy

 

Well it appears that the ring I did buy off ebay was not yours Andy so that may be the problem right there....my apologies. You will see my order in the next few minutes . I guess since I will be taking this compressor out again I will be more thorough on its cleaning and inspection. So since I have to take it apart should I freshen it up with the little beads and such? I don't remember them looking terrible, but than again I'm not sure what they looked like in the beginning. Anyway off to ebay I go.

 

I have conferred with Don B and am ordering a piston ring from Andy. My intention is combine everything into a one stop source for straightening out the old compressor once and for all time. I going to craft a post for the "HOW TO" section, so that instead of endless hour of speculation everyone will have some point of reference. It supposed to climb out of the below freezing point in the Polar Vortex of Wisconsin, so I get this done a soon as I can.

 

motofreak72,

I'm sure Andy will forgive you. For the benefit of others who will find this thread, the reason I opted to purchase the ring from Andy is that he had taken the time to produce an instructional video and post it on YouTube, as well as lots of vehicle-specific instruction manuals available at his website, and not only that, he manufactures the rings himself on precision machinery in his home shop. I have no affiliation with Andy - I'm just an impressed and pleased customer.

Regarding the replacement of the desiccant beads, it is not absolutely necessary. As part of the design of the system, the beads are partially-reactivated by back-flowing dry system air through the dryer bed from time to time to remove some of the adsorbed moisture from the surface of the beads. This reactivation is controlled by the ASCM.

The reason I decided to replace the beads in our compressor is that under normal use the beads are only "partially reactivated," and the car is 10 years old. The desiccant beads cannot possibly be as effective as they were when new, because not all of the moisture is removed from their surfaces, and there is a limit to how much moisture they can adsorb (off the top of my head I think it's around 22% of their total weight or volume). This no doubt leads to the possibility of moisture accumulation in the air suspension system, and since there is no water trap to allow the evacuation of collected moisture, I felt it would be prudent to replace the beads to adsorb as much moisture as possible going forward.

I am also considering installing a water trap, probably between the air reservoir tank and the valve block. There are very affordable traps that can be evacuated electrically at the press of the button, so that's what I will be looking at. The rust I found on the air dryer spring and the mineral deposits around the check valve tell me that moisture is no friend to the air suspension components.

To explain the difference between the air dryer built into the stock air compressor assembly and a water trap, the dryer uses desiccant beads to adsorb moisture from air that is drawn into the system and compressed by the compressor. The act of compressing the air also concentrates the humidity in the air, and the air dryer helps collect this moisture before the air passes into the suspension system. A water trap, on the other hand, condenses and collects moisture that makes its way past the air dryer. The trap has a valve that can be opened (either manually or with a solenoid) to evacuate the collected water from the system. Most aftermarket air suspension companies recommend the installation of both an air dryer and a water trap.

Cheers,

Don

 

Hi guys, of course motofreak72 i forgive you!! , Thanks for your support, I initially "invented" and designed & manufactured this solution back in march 2012 see my original post:

Allroad Air Suspension Compressor strip & repair

since then a few others have bought and copied my solution but "copied" is loosly used to describe their solutions as some are pretty rubbish.
I have sold 2500 to date and take pride in manufacturing every one from my home workshop, my kit is only available from me, i do not sell through a re-seller, I plan to have a US distributer soon to get them accross the pond quicker it should be in place next month

It should fix your problem motofreak72, to be honest i would just change the ring the compressors are "generally" are in good condition, a few Landrover owners have submerged their compressors when offroading so you can imagine they are in a worse state and need further stripping but generally only the ring needs changing, of course there is no harm to take it appart it comes appart quite well but dont loose any parts!! there are 2 o-rings in behind the drier chamber and a few springs and things, loose any and it will not work.

for more info about me and my kit see www.bagpipingandy.com for more info

best regards

Andy

 

As Andy, you are such an expert, what are your views on the air dryer. On my car, every so often after a run, I hear a whoosh from the front of the car as the system purges the dryer, but the question is, how effective is this process. And what about the terrible freezing conditions in the USA ? The system assumes it is blowing out water, but ice will be much more likely in the US winter, so the water trap may not get purged.

 

Hi Fraser,

Just to chime in here, see my post above regarding the distinction between an air dryer, which the Wabco compressor does have, and a water trap, which it does not have. The terminology is important because an air dryer and water trap are not the same thing.

If you will do a little research on desiccant beads (my photo series linked above explains the basics), both silica gel and molecular sieve can be fully reactivated, but it requires far more heat than the beads will ever receive while installed in the car. Silica gel requires 250 degrees F (121C) for 3 hours, and molecular sieve requires 400-600 degrees F (204-315C) for 15 hours in a nitrogen or argon atmosphere, alternated with high vacuum. Obviously, the desiccant is never going to be completely reactivated in normal use, no matter how much dry system air is back-flowed through the air dryer.

That's why I decided it would be prudent to replace the old beads with new, fully-activated beads. If your original beads are silica gel, you have the option of baking them on a cookie sheet in a 250F/121C oven for 3 hours. If your beads are molecular sieve, you can bake them at 400-600 degrees for 15 hours, but unless you can provide an oxygen-free atmosphere they still won't be fully-reactivated.

My two cents!

Cheers,

Don

 

To clarify not all dryers are desiccant beads, this is just one way

On my shop compressor I use an old a/c condenser to do this which is far more efficient than desiccant beads and does not require reactivation

The condenser is mounted to the side of the compressor over the belt drive cover and fan. Hot Air from the compressor is routed into the condenser and then to the tank. The condenser cools tha air and separates the water which collects in the tank.
This water collection hapens anyway as air cools but if you are running the compressor it remains suspended in the air as the air to you tools is still hot.
The output from the tank has the normal regulator and water trap. This does not collect very much water because most is already separated.
I have also fitted an automatic drain that is just an air operated solenoid. The solenoid opens up briefly when the compressor turns off. The way this is done is to put a T fitting on the line to the compressor head that is used to relive the line pressure.

So I have a separator (ac condensor) and 2 traps (the tank/auto drain and inline trap)
Desiccant beads are both a separator and trap but the longer it runs the less efficient it gets

Cheers
34by151