W220 airmatic issue

[design guru]

I have a w220 2001 S320 cdi, recently I have noticed when parked up over night the car raises to the maximum height, even when I unlock the car usually it drops by releasing the pressure but it remains at maximum height.

It does go down to normal heigh once I begin driving but the raises up when parked up. Very odd as I usually read about cars dropping overnight.

Any suggestions on any obvious symptoms that can cause this issue.

 

[design guru]

Well considering I had not takers on a possible reason for this I decided to take a good look, the first part was the filter, not sure what its supposed to be like inside but mine is like a rock, I have soaked it in some water to see if it does anything but either way it probably needs replacing.

The problem now is the front end has begun to drop overnight slightly, the rear still raises and I have checked to top of the strut and there are no leaks there. It never drops to the point where it says its to low to drive but whilst driving it keeps running the pump every 5-10 minutes but at no point does it warn of an air-matic issue.

I went on holiday a few months back and whilst the car was at maximum height and disconnected the battery for 10 days and when I got back it was still at maximum so I assume the struts are fine.

I sprayed some soap on the valve block and can't see any air bubbles but when I pressed the raise button but it would not raise, but did raise when I removed the filter.

I am going to replace the filter but could the filter be the cause of these symptoms?

 

[Benzowner]

Must have missed this originally.

I am speaking from a rather old memory, I had a 1999 W220 with air suspension and remember vaguely not being able to drive the car when the suspension is raised, it lowered itself, probably for safety and stability reasons. Have you checked the wiring to the height adjuster switch? If there is some corrosion, it may be set to max height. I can't remember there being a filter on the system, but as said it is a long time ago. Best of luck.

 

[Lyserman]

MB designed the system to have a self-cleaning filter by releasing the pressure back through the filter and blowing out any trapped dirt. But I think it doesn't work that way as my filter was an absolute mess and a new one is cheap and easy to replace.

It could be that your control block is leaking internally or is not moving properly to direct the air where it is needed. They are not cheap to buy but are easy to replace.

Check the sensors (2 front, 1 rear) and book a session on Star at a trusted indie. They will run the tests on the system and will highlight any problems. As you are in Hampshire then I would recommend PCS to check it out for you.

 

[design guru]

I am aware of the valve block can be the issue here but I need to get the car supported on all corners before I remove the airlines to check the condition as the car will collapse, MB sell them for about £230+VAT but I have seen a modified design on the market as the original design was prone to take in moisture. The new design is £180 and comes with a 2 year guarantee so I will try it if the valve block is the culprit.

PCS is just up the road from me so I will try to get it booked in, I work far from home so I am never available during their working hours.

I did raise the car a day ago before I removed the filter and it is still at maximum height so I know the struts are not leaking air. All sign do point to the valve block but I will get it plugged in before I change it. As Lyserman said it it could just be a sensor.

 

[AMGeed]

PCS is just up the road from me so I will try to get it booked in, I work far from home so I am never available during their working hours.

PCS have a courtesy car if needed. OK its an old C Class beater, but its transport

 

[design guru]

Right so I got around to fitting the filter and the new filter looks a damn slight better than the one that was in there. After fitting the sensor I lowered the car and noticed the front end was sunk down so I started the car and hoped it would automatically rise up, its always done that in the past when I have had my tires replaced but for some reason it will not rise. I can hear the pump running but the front end is refusing to rise. I have checked the top of the strut and there are no leaks.

Plan was to get the codes read after fitting the filter as parts after this point are quite expensive but not the car is to low to drive. Pump runs for a good few minutes but the car will not raise in the front, the back end is jacked up like a drag car. even when I lock the car it runs the pump for a few seconds and then switches offend agin when I unlock the car it starts to run the pump for a few minutes and then stops but it does not raise the car in the front. I am guessing the pump running is it trying to sync up to the sensors telling it the car is to low. but why its not rising is the problem. Can the pump be knackered despite it running?

 

[design guru]

Looking at the pump I decided to check it the best way I could without a diagnostic tool by removing the air line that goes to the valve block and turning it one, it blew out a weak stream of air. So the pump was either gone or possibly be repaired with a new piston ring (repair kit £15-25). A few month back I noticed the pipe from my filter to the air compressor was completely deteriorated there for it would seem the pump had been taking in unfiltered air and dirt. Also the clamp that held the compressor in place was damage in that only 2 of 3 the arms that hold the compressor in place were not damaged so the compressor was held on to the third leg with cable ties and to top it off the springs and rubber bushes that reduce the sound were shot meaning when the pump was running you would know it was running as it would cause a vibration on the pedals and in the cabin!

Problem 2 was every night the car would raise to maximum which after reading an article on the Arnott website a faulty valve block can cause this as a fail safe precaution it would pump all the air into the struts so that the car would not sink if it found a blockage or leak in the block.

As I could not get the car moved as the car had lowered to the point where my trolley jack was wedged underneath I made the decision to by the parts. I knew the struts were not leaking as I went on holiday a few months back and while it was raised I disconnected the battery for 10 days and when I got back the car was still at maximum height.

So A new compressor (£115 maxspeedingrods), new bracket with bushes, springs and air pipes from filter to compressor (£72 from Mercedes Dealer) and Valve Block but the updated version which is used in the newer mercs (£190 delivered from Germany - www.air-suspension-shop.com)

Removed the under tray on the drivers side and also the wheel lining for the best access.

The new design is supposed to be an updated design to the original as the original Mercedes version was prone to moisture. Either way it was cheaper and has the same 2 year warranty so I was happy. Where on the old valve block the pipes were connected via a 10mm bolt and a special steel valve that locked the pipe in place the new design the screws the pipes connect to do no remove from the block they are secured in so all you do is remove the pipe from the valve block remove the screws and seal valve washer, and clip the pipe with a special cutting tool supplied so its has a straight clean cut and then just push it into the corresponding hole in the new block. You may need to do the one at a time if the colour coding has worn off but luckily for me the pipe all were marked up with the part numbers and codes further up the pipe.

Installed the new bracket held in place with 2 13mm screws and a 13 mm bolt. New block with all new pipes pushed in place mounted on top and new compressor installed with new sound proofing bushes and springs. New valve block does not need to be reprogrammed just reconnect the battery and leave the car running with the raise switch activated to re-pressure the system while all the wheels are slightly off the ground so not to much pressure is applied the bellows when filling up.

after 10 mins of the car running and pressure had built up I turned off the raise button and I slowly lowered the car back to the ground over the space of 10 minutes bit by bit so the air would keep filling the struts to make it level set be the sensors. once the car was fully lowered and I could finally after 3 days remove the trolly jack I hit the raise button and the car instantly rose up and the sound was barely noticeable and thats despite the wheel lining and under tray not attached.

The next day I checked the car and it was still sitting at the same height, had not raised or dropped. An absolute result and most importantly the pump does not run whilst driving anymore.

My old bracket still has the 3 arms but because one arm had snapped off about 2cm and that was the part that contained the thread I could not use the bolt to secure the pump. The main part is the rubber mounts and springs, they make all the difference in the sound. The old valve block had a lot of limescale and dirt in the holes. so it seemed there was quite a bit of dirt and moisture that had bypassed the filter and pump.

If I had got it checked on star it could have been just a case of repairing the pump or cleaning the valve block, but because of the situation I was in and the problems it had been giving over the last few months I feel it was long overdue to replace the block and pump. It took about 3 hours to do the job, probably quicker If I removed the bumper for even more access but just the wheel, wheel lining and under tray was sufficient.

 

[BelfastBill]

Good post.

 

[design guru]

Just a quick update, my car decided to drop and would not raise again, despite hearing the pump running when the raise button was pressed or even when the door was opened it would run as the sensors was telling the pump to run to raise the car.

So the fuses and relays were working, they communicated with the pump on comand but the car would not raise despite having a new pump and valve block fitted. I called the RAC in the hope they could shed some light. They plugged in their machine and said it may find a problem but said Star would be the best bet as it was more suited to this problem but this RAC guy new about air suspension being an expert on the Land Rover. The computer found a list of fault codes but mainly pointed to the ECU which had a continuous fault despite clearing it it seemed the ECU was not communicating with the valve block to open and send air to the struts. He suggested getting a second hand one but was not sure if it needed to be programmed to the car as the air suspension ECU also house the ESP, ABS & BAS.

Either buy from Mercedes For £? (Did not even want to ask dreading the answer) or take a punt on eBay for £10. The car was barely drivable so £10 was worth a shot as it was the only part Showing a fault, well the eBay part arrived the next day fitted within 5mins as it was held in place by a clip and 3plugs, after disconnecting the battery and connected it all back. Started the car, cleared the abs and esp lights by full locking the steering wheel and all of a sudden the air pump ran and the car lifted. It's now sitting level again, I will leave it for the next day or so and test drive on the weekend. ECU was a straight swap and no programming required.

Big thanks to the RAC guy who was very helpful.

 

[design guru]

Well after 4 days of being absolutely fine it decided to stop again, and the message of the car being to low appeared, I managed to get it home but now the pump will not kick in even when I click the raise button. After a restart a message appeared saying faulty display and now the raise button does not even light up or the 2 lights on the switch that controls the sport setting is no longer working. Although the RAC pointed to the control module and I replaced the air suspension ECU which got it to raise, is there another module?

I will try to get it booked in so I can get it diagnosed during the week.

 

[design guru]

Charged the battery overnight, inserted the battery and the pump began to run, it did not raise the car but the sensors are telling the pump to activate as the car is low but still no lights on the car raise button or the suspension setting switch, before when the key was inserted to the second position these two switches had lit up until started, but now they do not. The only new message I get now is 'Display defective'

 

[zipdip]

I feel for you,sometimes you try your best and it is just not happening,get it booked into PCS Olly should be able to sort it,you have replaced most of the things it could be,a real puzzle,keep us informed .

 

[design guru]

I feel for you,sometimes you try your best and it is just not happening,get it booked into PCS Olly should be able to sort it,you have replaced most of the things it could be,a real puzzle,keep us informed .

It worked fine for the days it was dry weather, but happened on Sunday when it rained.

I found this thread and when I bought the car 4 years ago the wipers did not work so whoever had the car at the time rather than fix it by replacing the wiper stalk they just rewired the wiper to a separate switch. I corrected the problem but getting a new stalk fitted and getting it wired correctly so it all worked. So I saw this thread and feel it could be linked to the wiper fuses or wiring.

Everyone is booked up until next week so I may aswell investigate this route, could be a loose connection somewhere.

http://forums.mercedesclub.org.uk/index.php?threads/w220-defective-display-airmatic.105762/

Maybe I have the only S Class that will only run on dry days.

 

[Nigel06]

Try re setting the car to factory settings on dash

 

[design guru]

Well I dropped the car off to PCS and the verdict was the front struts are leaking quite heavily and need replacing. It seems when the car is raised and the wheels are off the ground when its lowered agin the front end sinks so I guess every time I hit a bump it was knocking the air out. Strangely it can stay up for days if left standing but does not hold the air when driven, although there could possibly be other leaks once replaced, but this looks like the main culprit. Also the ignition switch need replacing.

Can get replacement struts off the net for £300 but aftermarket and second hand ignition switch with 2 keys for £100 but will I need to reprogram the keys to my car? Need to do some research and weigh up the outcome. Car has lots of surface rust and maybe cheaper to cut my losses.

 

[design guru]

Well I spoke to PCS and Mercedes and it seems the EIS is a Mercedes part only which is factory programmed after he explained if a second hand key and EIS can be purchased then people would just buy it and remove the one from any car and install their one and steal the car.

I spoke to a few companies who can fix EIS modules and charge a fraction of the price but not sure how reliable that will be. I personally never noticed any problems with the EIS so I may just leave it and I also have a keyless-go card so I guess I can get away with it. I ordered the 2 front struts which are aftermarket but have a 2 year warranty (£280 - Maxpeedingrods vs £1400+ from Mercedes). Will update you when fitted if it resolves the issues I have had.

 

[design guru]

Right…an update.

Parts arrived 2 brand new struts from Germany. Then came the worst part, Mercedes decided to secure the strut to the bottom ball joint using 2 size 5 allen key fasteners, being rusty and so old they were pretty much seized on. Called the RAC as I had the option to and they tried to loosen them but only ended up damaging their tools. After they left I gave a final try and managed to get 3 of the 4 off before my old but trusty ratchet bit the dust. One strut pretty much collapsed when I released the pressure and after a bit on shaking it came out, this is the one I had a loose boot cover and I was pretty sure was on it way out even before getting it checked but as the car stayed up I thought it would just keep going. All changed, wires back in and wheel back on. 50% done.

Other side decided to drill out the fastener, only 1.5cm long but it fastens to the ball joint stem so over drilling it will damage the ball joint. It got quite late so I called it a day, back at work Tuesday so will pick up on Wednesday, looks like an L.A lowRider at the moment.

Only thing I did notice the strut on the passenger side has not collapsed and has remained extended despite it releasing quite a bit of pressure, have I missed something as I thought it would be able to possibly wiggle it and see if it came loose at the bottom where I had drilled out most of the nut.

I will say there is no need to tighten the size 5 allen key fasteners on so tight, they pretty much act like brake disc bolts just to secure it to the ball joint and then the weight of the car hold it in place, probably there so when the car is lifted the bottom of the strut does not fall out.

Despite being after market struts they fitted perfectly and look spot on, not pressurised the one thats in there so I will let you know if there is a compromise in the drive quality. £280 delivered for both front left and right I could not have asked for more + 2 year warranty.

Any thoughts on why the passenger strut has remained solid and how I can get it to collapse will be very welcome. The only thing I have not done on the passenger side that I did do on the other is remove the electric wire but the battery was disconnected before I started work on the car.

 

[BelfastBill]

Nice report, just waiting for the next instalment.
Bill.

 

[design guru]

Any thoughts of releasing the pressure I stuck a screwdriver in the valve and lifted it and it released some pressure but the strut is remaining quite rigid.