Loud airmatic pump - runs constantly too - 05 s500 4matic
11-11-2014, 07:32 PM
#1
Newbie
Thread Starter
Join Date: Nov 2014
Posts: 8
Likes: 0
Received 0 Likes
on
0 Posts
2005 S500 4matic
Loud airmatic pump - runs constantly too - 05 s500 4matic
Hi.
My airmatic pump runs frequently and it is very loud. Here are the symptoms...
- Car doesn't have to sit long, while doing errands turning car on and airmatic pumps kicks on within a few seconds.
- The pump itself is loud. Not sure if this is a sign of the pump going bad or if its due to the bracket. I plan on getting under there this weekend, but it doesn't sound healthy (and the longer it runs, it actually quiets down a bit). When its cold it is at its worst.
- In looking for leaks, I measured each fender height immediately after turning the car off. I let the car sit for a few days and remeasured. Not too much drop, I measured ~ 1/2" at one wheel and ~1/4" at another. I'm not sure if this is normal.
- I drove the car on the thruway for about 100 miles. Pump didn't kick on too much however, when braking it would kick on.
- Car does level itself out, it does not collapse so we are not in a failure mode.
- No evidence of sticky relays.
So here are my questions:
- Is it possible that there can be air loss or a leak at the pump - perhaps a valve? I ask because of my observation that this happens most when braking and most of the braking force and momentum shifts to the front of the car. Video here prompted the question:
- How long should these pumps last? I am not the first owner, car has ~130k miles. I watched a youtube video that showed the original design of the pump
- Do you think the pump is going bad if it is so loud?
- Is settling normal (max 1/2")? Or should there be no change at all?
- I am usually the only occupant in the car. Curious if there are any rules of thumb as to how often this should be kicking on.
Thank you to the community.
My airmatic pump runs frequently and it is very loud. Here are the symptoms...
- Car doesn't have to sit long, while doing errands turning car on and airmatic pumps kicks on within a few seconds.
- The pump itself is loud. Not sure if this is a sign of the pump going bad or if its due to the bracket. I plan on getting under there this weekend, but it doesn't sound healthy (and the longer it runs, it actually quiets down a bit). When its cold it is at its worst.
- In looking for leaks, I measured each fender height immediately after turning the car off. I let the car sit for a few days and remeasured. Not too much drop, I measured ~ 1/2" at one wheel and ~1/4" at another. I'm not sure if this is normal.
- I drove the car on the thruway for about 100 miles. Pump didn't kick on too much however, when braking it would kick on.
- Car does level itself out, it does not collapse so we are not in a failure mode.
- No evidence of sticky relays.
So here are my questions:
- Is it possible that there can be air loss or a leak at the pump - perhaps a valve? I ask because of my observation that this happens most when braking and most of the braking force and momentum shifts to the front of the car. Video here prompted the question:
- Do you think the pump is going bad if it is so loud?
- Is settling normal (max 1/2")? Or should there be no change at all?
- I am usually the only occupant in the car. Curious if there are any rules of thumb as to how often this should be kicking on.
Thank you to the community.
11-12-2014, 10:11 AM
#4
MBWorld Fanatic!
Some possibilities:
- The air filter was missing on the Airmatic pump on my 2003 S430. When I replaced it, pump operation was much quieter.
- The pump supports are pretty elaborate, including springs and rubber cushions. If the mounts are worn, damaged or just maladjusted, the noise level will greatly increase.
- The pump piston is likely worn. A replacement is about $25, not a difficult installation. My pump runs less with a new piston.
- It is possible to get the system totally leak-tight, but it isn't easy. I would be pretty happy with 1/2" drop over several days. Bubble solution is the easiest way to hunt leaks.
- DAS will test and show system performance. Low performance apparently doesn't show problems on the dash until the system can't keep the car above the minimum ride height.
- The air filter was missing on the Airmatic pump on my 2003 S430. When I replaced it, pump operation was much quieter.
- The pump supports are pretty elaborate, including springs and rubber cushions. If the mounts are worn, damaged or just maladjusted, the noise level will greatly increase.
- The pump piston is likely worn. A replacement is about $25, not a difficult installation. My pump runs less with a new piston.
- It is possible to get the system totally leak-tight, but it isn't easy. I would be pretty happy with 1/2" drop over several days. Bubble solution is the easiest way to hunt leaks.
- DAS will test and show system performance. Low performance apparently doesn't show problems on the dash until the system can't keep the car above the minimum ride height.
11-28-2014, 12:54 PM
#5
Newbie
Thread Starter
Join Date: Nov 2014
Posts: 8
Likes: 0
Received 0 Likes
on
0 Posts
2005 S500 4matic
Changed Pump.... "Somewhat" better
So, I ordered a new pump and changed it. It is "better", but not fixed.
What's better:
- Whereas before the pump would kick on all the time and frequently throw an airmatic failure message, that does not happen anymore. The pump used to kick on ~ 5 seconds after starting, now it doesn't until I start driving. For the first two minutes or so the pump will run and shut off intermittently. After that, it pretty much stays off the rest of the ride unless I press the button on the dash to raise.
- It seems to kick on when it should. Car does not settle or anything, I do not believe there are any leaks anywhere.
What's not better:
- The vibrating noise is still there! Its not AS bad, but definitely still noticeable and you can feel it on the accelerator too.
New Information:
I took a look again today and removed the new pump and I could see the distribution valve above was poorly zip-tied to the pump bracket as the rubber buffers appear to have failed (not the rubber mounts w/ springs on the pump but the rubber feet on the distribution valve!). I re-oriented the valve and freshly zip-tied - its tight and not going to move! I figured this must have been the vibrating noise as it would have been metal on metal. I thought that the shield that connects Excitedly I took the car for a ride, vibration came back, and a huge f-bomb could be heard a mile away.
What's INTERESTING:
When I got home and parked in the garage, left the car running, and for giggles I hit the airmatic button on the dash. Display said "car rising". The car rose, and it was quiet as could be. I then hit button again, and after a moment the car started to drop. Hit the airmatic button again, car rose..... did this 5 times, each time worked perfectly AND NO VIBRATION!!!!! How is this even possible.
CONFUSED!!!!
Add'l questions:
- Could the replacement pump be bad? Seems unlikely.I am confident the last pump had a leak and explained why it was always running and why the new one does not - so I feel like the pump definitely needed to be replaced.
- On a different thread I saw something about a pump filter. Is there a part number or something that I can reference? Never saw this left of detail in any other posts.
- Is this possibly NOT the airmatic pump? I also saw something about an ABS pump? I just can't understand how it was so quiet when in a parked position but not when moving.
- Is there something else - possibly airmatic related other than the pump that could be causing this?
Also, the bracket that the pump connects to seems pretty solid as I wanted to rule that out. It was slightly corroded, but nothing that I could find that would explain this.
Scott
What's better:
- Whereas before the pump would kick on all the time and frequently throw an airmatic failure message, that does not happen anymore. The pump used to kick on ~ 5 seconds after starting, now it doesn't until I start driving. For the first two minutes or so the pump will run and shut off intermittently. After that, it pretty much stays off the rest of the ride unless I press the button on the dash to raise.
- It seems to kick on when it should. Car does not settle or anything, I do not believe there are any leaks anywhere.
What's not better:
- The vibrating noise is still there! Its not AS bad, but definitely still noticeable and you can feel it on the accelerator too.
New Information:
I took a look again today and removed the new pump and I could see the distribution valve above was poorly zip-tied to the pump bracket as the rubber buffers appear to have failed (not the rubber mounts w/ springs on the pump but the rubber feet on the distribution valve!). I re-oriented the valve and freshly zip-tied - its tight and not going to move! I figured this must have been the vibrating noise as it would have been metal on metal. I thought that the shield that connects Excitedly I took the car for a ride, vibration came back, and a huge f-bomb could be heard a mile away.
What's INTERESTING:
When I got home and parked in the garage, left the car running, and for giggles I hit the airmatic button on the dash. Display said "car rising". The car rose, and it was quiet as could be. I then hit button again, and after a moment the car started to drop. Hit the airmatic button again, car rose..... did this 5 times, each time worked perfectly AND NO VIBRATION!!!!! How is this even possible.
CONFUSED!!!!
Add'l questions:
- Could the replacement pump be bad? Seems unlikely.I am confident the last pump had a leak and explained why it was always running and why the new one does not - so I feel like the pump definitely needed to be replaced.
- On a different thread I saw something about a pump filter. Is there a part number or something that I can reference? Never saw this left of detail in any other posts.
- Is this possibly NOT the airmatic pump? I also saw something about an ABS pump? I just can't understand how it was so quiet when in a parked position but not when moving.
- Is there something else - possibly airmatic related other than the pump that could be causing this?
Also, the bracket that the pump connects to seems pretty solid as I wanted to rule that out. It was slightly corroded, but nothing that I could find that would explain this.
Scott
