When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I've seen alot of posts on the Airmatic suspension on this board.
What I haven't been able to find is a writeup or diagram of our Airmatic suspension systems which would be helpful.
As the title says, the car is dropping at the front and back when it sits in the cold for 8+ hours but rises when started again.
I figure there must be a leak somewhere.
The problem didn't show up during this summer, or if it did, it was a minimal drop that I didn't see.
Has anyone been able to find a writeup or diagram ?
My first guess would be too much water in the system, what amplifies thermal volume changes.
Might be good time to bake drier granules and replace air filter as well?
The system has a software that controls the compressor and prevents it from overheating, but giving no feedback to driver till disaster strikes.
I did add pressure gauge to my wagon in the past, but adding control light to compressor relay would let you know when the compressor works overtime as well-potentially avoiding bigger expenses.
I've seen alot of posts on the Airmatic suspension on this board.
What I haven't been able to find is a writeup or diagram of our Airmatic suspension systems which would be helpful.
As the title says, the car is dropping at the front and back when it sits in the cold for 8+ hours but rises when started again.
I figure there must be a leak somewhere.
The problem didn't show up during this summer, or if it did, it was a minimal drop that I didn't see.
Has anyone been able to find a writeup or diagram ?
if its droppin in front and in thr back its gotta be more than rear airbag issue... because when i had that my front stayed the same and only fear would sag. Replacing it with Arnott one did it.
You can find my topic in W211 section under compressor rebuild.
Later on I found the wagon air tube to run under rear seat and now -that would be my favorite spot to install a Tee for gauge.
I've seen alot of posts on the Airmatic suspension on this board.
What I haven't been able to find is a writeup or diagram of our Airmatic suspension systems which would be helpful.
As the title says, the car is dropping at the front and back when it sits in the cold for 8+ hours but rises when started again.
I figure there must be a leak somewhere.
The problem didn't show up during this summer, or if it did, it was a minimal drop that I didn't see.
Has anyone been able to find a writeup or diagram ?
What if it simply is temperature related. As you say it happens in cold. Can it be that you notice it in the morning when the car sits in cold night temperature after you park it while it is warmer?
All four corners dropping to me does not sound like a leak issue as it is very unlikely that you have developed four leaks at the same time.
I've been observing the cars behavior more than anything else since its been an extremely cold 5F (-15C) most days.
Its a little warmer today so I decided to take some height measurements at the wheels. After sitting over night in a garage for 12 hours at 16F (-9C) these are the measurements I got measuring from the floor going thru the center hub to the bottom of the fender lip.
Fronts - both 67cm (26.4 in). Back driver - 64.5cm (25.4 in). Back passenger - 65.5cm (25.8 in).
After starting the car, the compressor engaged for about 15 seconds and shut off. On the colder days (5F) the compressor would engage longer.
These are the measurements I got once the compressor stopped running with the car idling.
Fronts - both 67 cm (26.4 in). Back driver - 68cm (26.8 in). Back passenger - 69cm (27.2 in).
I was surprised by the same measurements in the front. When the car is in the 'dropped' position, its visibly clear the back is dropped, but it appears visibly like the front is dropped as well a little (although not as much as the back).
I'll be taking more measurements as the weather gets colder again and as the car is left outside in the extreme cold.
On another note, as I pulled into the garage one night, I shut the car off and got out looking at it for a couple of minutes. In those couple of minutes, the airmatic system released some high pressure air (hissing sound) which lowered the car visibly in the back. I didn't measure the drop at the time and I didn't notice if the front dropped.
Last edited by - Mover -; Dec 30, 2017 at 11:32 AM.
I've been observing the cars behavior more than anything else since its been an extremely cold 5F (-15C) most days.
Its a little warmer today so I decided to take some height measurements at the wheels. After sitting over night in a garage for 12 hours at 16F (-9C) these are the measurements I got measuring from the floor going thru the center hub to the bottom of the fender lip.
Fronts - both 67cm (26.4 in). Back driver - 64.5cm (25.4 in). Back passenger - 65.5cm (25.8 in).
After starting the car, the compressor engaged for about 15 seconds and shut off. On the colder days (5F) the compressor would engage longer.
These are the measurements I got once the compressor stopped running with the car idling.
Fronts - both 67 cm (26.4 in). Back driver - 68cm (26.8 in). Back passenger - 69cm (27.2 in).
I was surprised by the same measurements in the front. When the car is in the 'dropped' position, its visibly clear the back is dropped, but it appears visibly like the front is dropped as well a little (although not as much as the back).
I'll be taking more measurements as the weather gets colder again and as the car is left outside in the extreme cold.
On another note, as I pulled into the garage one night, I shut the car off and got out looking at it for a couple of minutes. In those couple of minutes, the airmatic system released some high pressure air (hissing sound) which lowered the car visibly in the back. I didn't measure the drop at the time and I didn't notice if the front dropped.
Mine does the exact same thing. It also won't come out of sport mode when under 32 fahrenheit, at least not until it's driven for awhile, stopped, raised suspension, turn the car off, turn it back on and it will start in comfort mode again. Rear right corner is visibly lower by at east 1/4 to 1/2 inch at all times, that's how it was the whole summer too, but only when very cold does it behave badly until it gets driven for awhile. I couldn't find any leaks, so I'm thinking there's a bad sensor somewhere, but I don't know anyone with a STAR diagnostic tool in my area (except from the Stealership) to figure it out. The car is still drivable, but it's just annoying to go through the steps to get it to do what I want.
I've been observing the cars behavior more than anything else since its been an extremely cold 5F (-15C) most days.
Its a little warmer today so I decided to take some height measurements at the wheels. After sitting over night in a garage for 12 hours at 16F (-9C) these are the measurements I got measuring from the floor going thru the center hub to the bottom of the fender lip.
Fronts - both 67cm (26.4 in). Back driver - 64.5cm (25.4 in). Back passenger - 65.5cm (25.8 in).
After starting the car, the compressor engaged for about 15 seconds and shut off. On the colder days (5F) the compressor would engage longer.
These are the measurements I got once the compressor stopped running with the car idling.
Fronts - both 67 cm (26.4 in). Back driver - 68cm (26.8 in). Back passenger - 69cm (27.2 in).
I was surprised by the same measurements in the front. When the car is in the 'dropped' position, its visibly clear the back is dropped, but it appears visibly like the front is dropped as well a little (although not as much as the back).
I'll be taking more measurements as the weather gets colder again and as the car is left outside in the extreme cold.
On another note, as I pulled into the garage one night, I shut the car off and got out looking at it for a couple of minutes. In those couple of minutes, the airmatic system released some high pressure air (hissing sound) which lowered the car visibly in the back. I didn't measure the drop at the time and I didn't notice if the front dropped.
As you measure both fronts the same but have the rear passenger side measurement higher check your floor where the rear tires are. Only the rear having difference kind of tells of the uneven floor as if one of the rears goes lower then the opposing front should get higher, but you measure fronts the same.
As it looks by the measurements that your rear driver side goes lower then the front passenger side should get higher as the car's body is rigid. I don't believe that it would flex that much to allow one tear to lower without effecting the front at all.
From what I heard MB gives the level 19 mm tolerance, so your 10 mm rear difference is well between.
Yeah, the government did the same thing with classifying obese people, just so they wouldn't have to deal with taking care of them, that doesn't make it the right thing to do.
As you measure both fronts the same but have the rear passenger side measurement higher check your floor where the rear tires are. Only the rear having difference kind of tells of the uneven floor as if one of the rears goes lower then the opposing front should get higher, but you measure fronts the same.
The garage floor has a slight tilt to it; the back of it being slightly higher than the exit. I back the car into the garage.
I understand what you're saying about the opposing side being raised, however, the tape measure says otherwise.
I'm going to drive it in forward and measure again.
After 3 hours of letting the car sit I measured again without starting the car. Some pictures below. By the way, I'm 185 lbs although the car was empty when these were taken.
When the weather gets warmer, I'll watch the car for 10-15 minutes after shutting it down to see if the airmatic system releases compressed air and the amount it drops the rear at the same time.
Fr Left (driver)
Fr Right (the tape was straight but the camera was angled)
Rear Left
Rear Right
Last edited by - Mover -; Dec 30, 2017 at 06:51 PM.
These last measurements to me tell that the opposing corner (Right Front) is higher when the lower rear corner (Left Rear) is down as it should be if that LR air spring leaks.Assuming you have absolutely level (straight) floor, which it probably is not, when you park your car it will lower to the pre-set position after the down force is gone and the stopped car raises up. This happen very quickly after car is off and you exit the car and close the door. In mine it happens in just a few seconds after closing the door. If the floor is level the measurements should be the same in each axle (probably all the same) but in your earlier post you measured the difference in rear with fronts dead even when the car was running. This to me says your floor must have some lower or higher spots where your rear tires sit.The AirMatic compressor does not run if the car is off. I think this is to save battery in case you park for a long time with leaking system. My old Lincoln did run the compressor and drained the battery on me a couple times when I left it at airport for a week during my work trips. AirMatic only lets air out if car raises up for any reason like temperature raise but it does not fill the springs in case the car lowers for leak or for colder temperature.You may have a leak on your driver side rear spring as based on the measurements you right front is higher than left front but this measurement should be done on absolutely level (straight) floor.If you have the 3 mm difference in the front when you stop the car but leave it running then I think you may have level sensor issue in the rear (either side).
The data posted here ( I remember thanks to konigstiger) tells that full airmatic activates with each door opening and when the air tank supply is not enough to level the car, it will start compressor. No personal experience, but would be interesting to sit 2 people in cargo area and open driver door observing if the level will change with engine off.
The data posted here ( I remember thanks to konigstiger) tells that full airmatic activates with each door opening and when the air tank supply is not enough to level the car, it will start compressor. No personal experience, but would be interesting to sit 2 people in cargo area and open driver door observing if the level will change with engine off.
It will if it has enough pressure in the air reservoir. Once that is depleted, it won't do anything with the engine off, the air compressor will never start if the engine is not on.
when you park your car it will lower to the pre-set position after the down force is gone and the stopped car raises up. This happen very quickly after car is off and you exit the car and close the door. In mine it happens in just a few seconds after closing the door.
I'm not sure what you're saying. Is it this ?
1) turn ignition off and get out of car
2) car lowers to preset position
3) car raises
I was out driving today and found an underground garage and went to the bottom floor. Its warmest there.
I stopped the car, turned the ignition off and got out. I didn't hear any compressed air being released (although I have on occasion after getting out of the car)
What I did notice after opening the door (and leaving it open as in not swinging it shut) and sitting in the drivers seat again, was some air movement taking place in the rear suspension drivers side as I sat down.
It wasn't a 'pssstt' like compressed air being released, but more like something was being deflated for a few seconds.
Either way, it runs fine, inflates in seconds after 'dropping' in the cold so I won't be getting under the car to look at the level sensors for now until it warms up a bit.. Its still freezing outside 7F (-14C)
I'm not sure what you're saying. Is it this ?
1) turn ignition off and get out of car
2) car lowers to preset position
3) car raises
I was out driving today and found an underground garage and went to the bottom floor. Its warmest there.
I stopped the car, turned the ignition off and got out. I didn't hear any compressed air being released (although I have on occasion after getting out of the car)
What I did notice after opening the door (and leaving it open as in not swinging it shut) and sitting in the drivers seat again, was some air movement taking place in the rear suspension drivers side as I sat down.
It wasn't a 'pssstt' like compressed air being released, but more like something was being deflated for a few seconds.
Either way, it runs fine, inflates in seconds after 'dropping' in the cold so I won't be getting under the car to look at the level sensors for now until it warms up a bit.. Its still freezing outside 7F (-14C)
Thanks to everyone for all the replies.
What I'm saying is that when you drive the car the movement of the car creates down force that pulls the car down. AirMatic adds air in the springs to return the car to the correct height. When you stop driving or drive slowly long enough the AirMatic lets air out from springs as without speed the car raises up higher than the set level.
I live in an area where I can drive to my house from a highway in just a minute after leaving the highway with 55 mph speed limit. That one minute at 30 MPH is not long enough for AirMatic to drop the car down yet so when I get home and exit the car and close the door the car lowers down as the down force is not present and car is sitting too high.
AirMatic does not change car height immediately when you stop in traffic. If it did it would be lowering the car at every stop light where you stop and pumping it up again after you start moving so the system has some sort of a time delay before it lowers the car. If you add load I think it will immediately start pumping air in the springs to raise it up to where it needs to be.
Another observation - I had to go to the car which was sitting in the garage all night and get my gloves this morning. Its still cold outside 16F (-9C).
The car was sitting a little low at the rear. I opened the rear door (without starting the car), sat in the back seat to get my gloves and got out of the car and closed the door.
The car started to raise in the back once I closed the door. Compressor didn't engage which is how its designed from what others have said. It must have still had pressure in the reservoir to raise like it did and there must have been electricity to the circuits which level the car for it to raise like it did.
I've found the same thing with our car. When -1 degrees Celsius it drops probably about as far as it can at the back. When above zero degrees it does not drop. I wonder if there is a sensor in the system that prevents freeze cracking or something?
What if it simply is temperature related. As you say it happens in cold. Can it be that you notice it in the morning when the car sits in cold night temperature after you park it while it is warmer?
All four corners dropping to me does not sound like a leak issue as it is very unlikely that you have developed four leaks at the same time.
When it is temperature, I think this is precisely freezing-related.
The system is not giving you any warning about small leaks. Meaning owners might drive the car for year and compressor simply keeps pumping.
But the system is also using return air for blowing the moisture from dryer, so with no return is present, the dryer accumulate lot of water, eventually pushing it all over the system.
Than comes the freezing and everything stops working till the temperature raise.
That is why I installed the pressure gauge as I mentioned above and I wonder if modern scanners can monitor the system pressure.
The oem rubber springs / bladder only last 7 or 8 years before starting to have leaks via small tears in them. I discovered this one day when I was in my garage for some time after parking the car.
Once it hit a certain height, I could hear the air coming out of the rubber 'spring' rather rapidly with a hissing sound and drop the car at that corner.
I've replaced any leaking ones with Arnott ones that have a lifetime warrenty.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
