mike_wall15

Hi everyone!

I would be grateful if anyone could help, as I can't find a similar issue using the search just yet.
I'll try and write down the story so far:

- Car was lower than usual, and especially on front right, and the 'visit workshop' light came on
- I couldn't find an obvious issue, so I took it to the main dealer so they could use Stars
- They said the compressor was faulty and breather hose broken, but wanted 1100 GBP to fix it
- I told them I'd do it, so picked the car up. The car was high again, so I assume they used Stars to fill it with air

- My new Aerosus compressor arrived and I fitted it today
- I also fixed the breather hose
- When I started the car I could hear the compressor, but the car began to fall. The compressor turned off after 10-15 seconds
- I tried again and it fell some more
- The car is now extremely low, and every time I start the car, the compressor will run for 10-15 seconds, before stopping, and coming up with the usual warning light

- I can feel air being sucked in from the compressor. I also changed the relay but there was no difference

Any ideas on what to try before I take it back to Merc again?
I am wondering if I have another problem all along, or something has broken whilst fitting the compressor.
I am confused how a new compressor has had the effect of letting air out!

Any ideas would be greatly appreciated
Thanks
Mike

IgorE350

Hi i am not an expert but id check for leaks first. like front shocks spray with soapy water then rear shocks all the lines that going to it, tank in the rear. Then, very important is to keep the wheel level sensors ball joints greased very often.
If you do the work yourself, buy a good scanner and do your own scanning, no need to pay dealer arm and a leg for guessing. They are there to rip you off.
Scan for codes and post them here i think i have print out for all airmatic error codes i can help you out, if u got a code. When you replaced the Pump you should've replace the valve as well and the relay. Id replace a hose that goes from the pump where it sucks the air in and the filter on it as well.
Another suggestion, driver side footwell there is a module check if there was no water damage.

mike_wall15

Thanks for your ideas on this Igor.
I guess what confuses me is how the new working compressor, can within minutes, drop me to a lower level than I’ve ever been at.

Does anyone know if the compressor to valve connection is poor, if it causes the whole system to lose air?

My original code was 5505 (recovery times) but I’m not sure what it says now, I just went with the main dealer diagnosis as I thought 5505 was pretty broad.

I didn’t change the valve this time as it looked pretty fresh, but I will check for a leak there in the morning.
I tried a new relay but it made no difference.

Breather hose and filter changed too.

The module idea is a new one to me. Wouldn’t that flag as a code?

Thanks
Mike

IgorE350

Hey Mike, to me looks like you got a air leak somewhere. Check the line from compressor to the valve, just take your time and check everything really good soapy water sprayer.
Dont think you got a problem with module but these W164 got lots of modules under seats and carpets in low spots of the car and they get damaged often.

mike_wall15

Cheers Igor. It was raining a lot today but I will check for a leak tomorrow. I am hoping that I've got a leak on the valve that I re-used for connecting to the compressor.
I am just trying to find a video on how to fit a new connector to the line!

thanks
Mike

IgorE350

Grease all 4 level sensor ball joints. Spray soapy water around compressor area an valve and lines in that area, wile pumping and wile off. good luck!

BlackML550

Sometimes the line between the compressor and the valve block can rub on the frame and over time it can wear to a point that it leakes. Also check the brass fitting on the white tube that is the outlet from the compressor to make sure its seals well. As the others have said, soapy water, starting at compresor and all the way to the rear. Raise it right up and pressurise the system as much as you can. Use jack stands. The car can still sink to a low level that won't allow enough clearance if you're under it.

mike_wall15

Hi guys
Thanks for the thoughts so far.
I have fitted the new compressor and now have the code 5508, which is linked to the ‘pressure line’.
Do you know how generic this is? Could it be the compressor - valve block line, or could it well be a leak in the actual valve block?
cheers
mike

Maj. Dundee

Here are the instructions to check for leaks.

mike_wall15

Thanks Maj for those documents, they may come in use later.

Just as an update, I was concerned that the new compressor wasn't giving out enough pressure, so I fitted the intermittent old one, and the pressures were similar, so I am confident the new is fine.
I also called the Mercedes dealer and asked them how they got the car to be high (after it'd been in). They said they'd lifted the car and then filled with air.

I assumed the car could lift itself from the floor if the system was fully working. Can anyone confirm this?

As the car always used to remain high when switched off, I am still focusing on the valve block, compressor, and pressure line in between.

Thanks
Mike

Maj. Dundee

Mike, you must own your own scanner to see what codes are stored in the Airmatic Module.

mike_wall15

Yeah I’ve got a scanner.
A few weeks ago it was 5505, which to me was quite generic, so I gave the car to a main dealer so they could use Star.

They said it was the compressor, but it hasn’t fixed the issue.

Now I’m on a code 5508, which again seems generic when you read about the problems people have that hit this code.

So forgetting the codes for one second, I’m just piecing together all info I have, and I think it must be valve block, or earlier in the system

Thanks
mike

mike_wall15

A bit of an update... over the last few days I'd swapped back to the old compressor so I could be sure the new one was working...
So today I put the new one back on, to take it down the road to a vehicle ramp. The car lifted all the way up!!!

So it lifted up and compressor turned off, then dropped a bit when I went into sport, but then when back to normal the compressor ran and it wouldn't stop. In fact, it felt from the pipe, and from the looks, that it was starting to fall again.
I turned the car off (which stopped the dropping).

I am even more sure now that I have a major electronic glitch, or that the valve blocked is knackered

Thanks
Mike

Maj. Dundee

Both codes point to a leak in the pressure line. That's why I posted the procedures.

mike_wall15

The trouble is, if it was a leak in the pressure line, then why would it raise the suspension to normal level and keep it there?
And with the car off, it hasn’t moved down at all

Thanks
mike

BlackML550

As you said the compressor kept working, which is the symptom of a leak as it keeps working to maintain pressure. Until you've done the soapy water test, you'll be guessing.

I've replaced all 4 airbags on mine and at times when they were leaking, they would maintain pressure overnight and fall the next day. There was no consistency to it. You should follow the previous advice from Maj. Dundee and eliminate the most likely cause, being a leak, first.

mike_wall15

I appreciate the thoughts and help from everyone but I really do think it's a valve block or electronic issue.

One minute it won't rise off the deck, the next its right to the top with compressor off and everything 100% perfect.
I fail to see how it's a 'leak' anywhere in the system now that I've seen it back to 100% ok.
It just sounds so much like a problem solenoid in the valve block not opening/closing correctly.

We will see I guess...

mike_wall15

Just to close this thread off... ISSUE SOLVED!

It turns out the Aerosus brand new compressor was faulty. It must be an internal thing, perhaps intermittent, as at times you could hear the compressor, see it rise, and feel the air go in.
I put in a genuine Merc compressor and the issue is sorted.

I am just waiting to hear from Aerosus now about a refund

Thanks
Mike