Airmatic issue

[fred_raven]

Ok so my airmatic visit workshop light has come on ! Did this once before and having searched the forums I changed the relay and its been fine for 6 months. But now I have the following situation, the car is level, I have done 200 miles since the light came on with absolutely no problem. I can hear ( I am sure ) the pump run when the car starts, but only for a short time. What it doesnt do is raise when you hit the button , it says rising but no movement. Still have the old relay , which seemed to be intermittent and putting that back does nothing. I have found a post on mbworld about a guy with a similar problem who found a cable disconnected on the pump which solved his problem! I will check this tomorrow,but whilst at it does anyone know what voltages etc I should be able to measure at the pump connector to ensure the control circuit is working as if it is ok then the fault could well be something within the pump !

 

[Alps]

pump could be on its way out, there are tests you can do via STAR which should help diagnose.

 

[shorty]

It sounds like the pump needs changing , best thing to do is get the car on a STAR dignostics machine .

 

[mct_cars]

Ok so my airmatic visit workshop light has come on ! Did this once before and having searched the forums I changed the relay and its been fine for 6 months. But now I have the following situation, the car is level, I have done 200 miles since the light came on with absolutely no problem. I can hear ( I am sure ) the pump run when the car starts, but only for a short time. What it doesnt do is raise when you hit the button , it says rising but no movement. Still have the old relay , which seemed to be intermittent and putting that back does nothing. I have found a post on mbworld about a guy with a similar problem who found a cable disconnected on the pump which solved his problem! I will check this tomorrow,but whilst at it does anyone know what voltages etc I should be able to measure at the pump connector to ensure the control circuit is working as if it is ok then the fault could well be something within the pump !

Is the noise you hear on start up not the SBC pump? It's quite difficult to hear the Air Pump (located under the front left corner behind the bumper).

The good news is that if you've driven it a couple hundred miles with the pump knackered, you don't have any leaks

 

[Auto-mobile]

No sbc on a s class!

 

[fred_raven]

On sat got the dreaded Vehicle too low warning, so major investigation time ! Checked fuses and opened relay and all appeared to be ok. Now all I have read indicates that if the pump has gone , the relay isnt working and the fuses probably gone too ! So I was hoping not a pump issue! Took engine cover off and all looked ok , although there was a kink in the thinner of the 2 cables ! Took connectors out and couldnt detect any voltage on either ! thought I would reconnect to see if moving cables around did anything ( possible damage due to the kink) On reconnection , pump cut in and all was well !! moved both cables and no difference ! I did cut the cable at the kink and soldered in a new section in case there was some damage , but now all is fine ! I am surprised there was no voltage at the power connector tho as the relay was definately working, i even changed it for the next one along as they were the same part no ! I cant think there is a fault in the power cable as its around 2mm thick ! Is it possible that a faulty control cable ( thinner one) would cause the power not to cut in?

Any thought gratefully received , in the meantime I will drive on and hope it doesnt reoccur safe in the knowledge that at least I dont need a £360 +vat pump

 

[shorty]

If the car detects a fault with the pump it will shutoff the power feed to the relay , when the car is restarted the relay will power up again for aout 30 seconds and then shut off the power feed again if there is a fault detected .
I the car was showing the vehicle too low warning then that would suggest that theres an air leak and this is causing the pump to over run .I has a problem with my pump where it did not work of over a month and it didnt show the car too low message . Has the car been on a Star dignostics machine yet ?

 

[IATM]

I was just browsing on the forum in general as I am looking at a benz with airmatic and wanted to see if help would be at hand IF something did go wrong


DAMMM !!!! you guys do know your stuff.... well done guys. great work:bannana:

 

[LTD]

I had a long-term problem with my S500 that wouldn't trigger anything on STAR so I'll give you my findings. Might help, might not but at least it's posted again !!

My car sat down overnight and gave a low height warning. Switched on and the pump popped the car back up and all was well in the world. The pump switched off after the car was back at it's normal height.

Then the pump decided to chuck it.

New pump and relay duly fitted. Car still sat down overnight.

Struts were checked for leaks and none found.

Decided that the course of action was to change the alloy air manifold that distributes the air around the car. Problem solved.

Once alloy corrodes it becomes porous to air - especially at 17 bar pressure !!!! My car was slowly leaking air through the manifold after a period of not being used triggering the sensors which, in turn, started the pump once the car was brought back from it's slumber.

Recently had it parked up for 4 days whilst we went on a cross-channel trip and came back to it all level and good as gold.

Don't overlook the air manifold leaking. It is cheaper than a new pump and might even save the one you have if it's the source of the problem.

 

[IATM]

I had a long-term problem with my S500 that wouldn't trigger anything on STAR so I'll give you my findings. Might help, might not but at least it's posted again !!

My car sat down overnight and gave a low height warning. Switched on and the pump popped the car back up and all was well in the world. The pump switched off after the car was back at it's normal height.

Then the pump decided to chuck it.

New pump and relay duly fitted. Car still sat down overnight.

Struts were checked for leaks and none found.

Decided that the course of action was to change the alloy air manifold that distributes the air around the car. Problem solved.

Once alloy corrodes it becomes porous to air - especially at 17 bar pressure !!!! My car was slowly leaking air through the manifold after a period of not being used triggering the sensors which, in turn, started the pump once the car was brought back from it's slumber.

Recently had it parked up for 4 days whilst we went on a cross-channel trip and came back to it all level and good as gold.

Don't overlook the air manifold leaking. It is cheaper than a new pump and might even save the one you have if it's the source of the problem.

Your not far at all from me

Atleast I know there is a genius at hand. haha. good work btw !!! Its one of those things that you know if you went to a mercedes dealer; most likely they look at the biggest things to replace first that "Might Cure" the problem without actually investigating it .... good work !

 

[Auto-mobile]

I had a long-term problem with my S500 that wouldn't trigger anything on STAR so I'll give you my findings. Might help, might not but at least it's posted again !!

My car sat down overnight and gave a low height warning. Switched on and the pump popped the car back up and all was well in the world. The pump switched off after the car was back at it's normal height.

Then the pump decided to chuck it.

New pump and relay duly fitted. Car still sat down overnight.

Struts were checked for leaks and none found.

Decided that the course of action was to change the alloy air manifold that distributes the air around the car. Problem solved.

Once alloy corrodes it becomes porous to air - especially at 17 bar pressure !!!! My car was slowly leaking air through the manifold after a period of not being used triggering the sensors which, in turn, started the pump once the car was brought back from it's slumber.

Recently had it parked up for 4 days whilst we went on a cross-channel trip and came back to it all level and good as gold.

Don't overlook the air manifold leaking. It is cheaper than a new pump and might even save the one you have if it's the source of the problem.

Valve body is common, especially if the complete car drops over night, I had a s500 last month with a airmatic pump that had blown a hole in its side, all the air it tried to pump into the system came straight back out again.

 

[arthurs320]

Hi guys I'm new owner 3arms star .... is my 4th Merc in my life but first "S" classe
I also have problem with Airmatic maybe someone knows a good mechanic around Redhill / Surrey cheers

 

[fred_raven]

UPDATE

I went out in the car on saturday , the airmatic light came on so stopped , locked car , unlocked and started again all ok, but now the damn thing has come on again! I have once before remove the power cable to the pump and on reconnection all was well. Is this likely to be a sign that there is a fault in the pump, albeit intermittent , or is there a possibility that there is a fault in the detection system? I am wondering because the car seems to throw all sorts of strange errors from time to time , which then clear them selves! I have had incorrect external temp readings, my command system occassionally switches itself off and on again , a few other one off errors have also appeared and then cleared themself! If it was put on a Star reader would these necessarily all show up and would the system be self diagnosing?

 

[amg_Charged]

I had a long-term problem with my S500 that wouldn't trigger anything on STAR so I'll give you my findings. Might help, might not but at least it's posted again !!

My car sat down overnight and gave a low height warning. Switched on and the pump popped the car back up and all was well in the world. The pump switched off after the car was back at it's normal height.

Then the pump decided to chuck it.

New pump and relay duly fitted. Car still sat down overnight.

Struts were checked for leaks and none found.

Decided that the course of action was to change the alloy air manifold that distributes the air around the car. Problem solved.

Once alloy corrodes it becomes porous to air - especially at 17 bar pressure !!!! My car was slowly leaking air through the manifold after a period of not being used triggering the sensors which, in turn, started the pump once the car was brought back from it's slumber.

Recently had it parked up for 4 days whilst we went on a cross-channel trip and came back to it all level and good as gold.

Don't overlook the air manifold leaking. It is cheaper than a new pump and might even save the one you have if it's the source of the problem.

what was the part no please of the part you changed, and any pic please, and cost

 

[steve333]

UPDATE

I went out in the car on saturday , the airmatic light came on so stopped , locked car , unlocked and started again all ok, but now the damn thing has come on again! I have once before remove the power cable to the pump and on reconnection all was well. Is this likely to be a sign that there is a fault in the pump, albeit intermittent , or is there a possibility that there is a fault in the detection system? I am wondering because the car seems to throw all sorts of strange errors from time to time , which then clear them selves! I have had incorrect external temp readings, my command system occassionally switches itself off and on again , a few other one off errors have also appeared and then cleared themself! If it was put on a Star reader would these necessarily all show up and would the system be self diagnosing?

Just a long shot but we're all the stored faults cleared on star when the new part was fitted?

 

[fred_raven]

still problems

Yes faults were cleared, had sytem fully checked, pump and valve tested fine, new relay fitted and all ok... one sensor was apparently reading incorrect this was sorted and car been fine for 2 weeks now its happening again, star tested and shows low pressure . But as soon as the fault is cleared system pumps up fine , but not for long !

 

[jaymanek]

your pump is on the way out or you have a leak...

 

[Alps]

agree with Jay, sounds like the pump is not keeping the pressure up or the leak is making the pump work harder .

 

[fred_raven]

it was leak tested and was ok, now I understand the pump is a possibility, but when this happened before I disconected the power connector to the pump and put a meter on it and there was no voltage ! so am wondering if there is something stopping the power being supplied?

Also , the car doesnt sink , so sure there is no leak !

 

[fred_raven]

Clearly if pump is kapput then will have it changed, just dont want a £400 bill and fault returns!