jk3504matic

Arrggghh...ok, I've been reading about airmatic issues. My 2007 E350 4Matic airmatic pump thumps for about 30 seconds upon shutting the car down prior to hearing the air release. Self diagnosed it to a faulty relay based upon the posts but post relay swap the issue remains...Is it possible that the faulty relay sickened the pump and this thumping sound means that the pump is on it's last legs? Dealer quoted my ~$350 for a new pump...

jk3504matic

Ok...relay not the issue, the thumping noise clearly caused by the pump moving within the bushings as I pulled the plastic skid plate across front and the pump is readily accessible, was able to recreate the thumping noise by simply rocking the pump agaist the bushings. Had a couple rounds of a "burning electric smell", presumably the pump, so i'll be heading to the dealership on Monday to pick up a pump and bushing kit...

jk3504matic

The saga continues...picked up the pump today from the dealer. Started removal of old pump, things were going well until lo' and behold the two wire connector was literally welded on, presumably due to the faulty relay...so the best case scenario is to pick up a connector tomorrow and splice it in or worst case, just splice the wires together while installing the new pump...why didn't I get the extended warranty???

jk3504matic

New pump is installed with everything buttoned back up. Note that splicing in the new wires into the harness was difficult due to lack of space, replaced relay as well. Note that in this 2007 E350 4matic sport, the pump relay sits in a separate carrier in the relay box "behind" the board, close to the firewall side. Unfortunately, pump still doesn't come on even though the vehicle raising light comes on...need to wring out wiring to make sure new connections are good. I bought the car in August, it is apparent to me that the harness and other items were replaced, my guess is that it was a bandaid fix to sell the car...

Diesel Benz

That is unfortunate after so much work and new parts. Did you check the big Airmatic pump fuse too? Do you have access to Star diagnosis? Would make fixing the car much easier.

jk3504matic

Thanks for the reply. Yes, I checked the 40 amp fuse and it was fine. To make matters worse, when I went out to the car last night to continue troubleshooting I pulled the hood release and guess what, cable disconnected. What is odd is that it looks like the drivers side of the hood is released but the passenger side is not. No time this evening to evaluate, tomorrow.

jk3504matic

Used info from this posting "Anyone Know How I Can Open My Hood With A Broken Cable " and found the plastic cover (A211 626 06 30) over the passenger side mechanism, wiggled off and manually released the mechanism...no need to remove inner wheel cover but is it necessary to have front plastic engine cover off (which is still off as I troubleshoot the airmatic). Here is to success in that endeavor as well

jk3504matic

Well, after one last day of tracing wiring signals, turned out that the fuse in the E350 for the airmatic pump is in the passenger footwell fuse block (with a blue wire)...once pulled (definitely broken) and replaced and buttoned back up, the car returned to normal ride height in less than 2 minutes. 100 mile commute today with no issues! Short summary, faulty relay took out the pump and the connection to the pump, presumably pulled too much current and popped the fuse. Word to the wise, the 40 amp fuse in the engine compartment is not in the circuit to the airmatic pump in this vehicle. Wiring schematic would have helped but that is the way it goes I guess.