sunnyk

Dear All,

I hope someone can shed some light on a part that has gone faulty?

Basically I parked up my c32 this morning after about a 15minute run and I could hear a spinning noise from under the bonnet even after swtiching the engine off and taking the key out. The spinning noise was coming from a black box which is below the coolant resevoir near the front headlight this would not switch off even after 10 minutes and after waiting another 5 minutes I decided to unplug the power going to it. this proved a challenge in iteslf as it was so damn hot. I am in no doubt that it would of caught fire if I had left it. Could someone please advise on what this part is and how much it costs as I am sure it is faulty however I have driven the car after disconnecting this and no warning lights have appeared on the dash but I would rather know what I am dealing with before going to the dealers.

Thanks

pshek

Sounds like it's the air injection pump. Might be a bad relay. I'd check the relays and wiring going to the pump before you replace it. Your car will still run fine without the air injection pump for now, since it's only used for reducing emissions at cold starts. It's supposed to turn off by itself though.

If it is the air pump, it should look something like this.....

Eleventeen

Exactly. It is a known issue (MB knows about it too). The relay sticks and burns the pump up. This would explain the fact that it kept running when it shouldn't. Disconnecting the pump will also cause a C.E.L. but no harm to anything.

sunnyk

Thanks for all your help guys!

You both seem spot on with your analysis. The motor has definately blown does that mean I will need to replace the relay as well as the pump?

Could you also advise me what C.E.L means and if this is a known issue does MB compensate towards replacement? Do they really cost £875 new?

Once again thanks for your all your help I really appreciate it!

c32AMG-DTM

CEL = "Check Engine Light" - just a common internet abbreviation.

MB might take care of you - do you have a good relationship with your SA (Service Advisor)? Mine went out and I was just barely out of warranty time-wise, but was still well under the mileage threshold; MB offered to replace the parts for free if I'd pay the labor. Saved me quite a bit - I think out-the-door I paid $300 or so.

Eleventeen

Most likely you will need to replace both relay and pump. I believe there's also a reflash that the dealership performs when cars come in with this issue. Since the ECU controls the pump's operation, I think they reprogram it to avoid burning up the pump. This is not just a random failure, this is an engineering shortfall that MB is aware of. Search some of the older threads on here; that's where I found all of the info on this subject

sunnyk

I have my service A booked for this Wednesday with my mb dealer so I am hoping they will sort out the issue as Eleventeen is stating that this is no random failure and that MB are aware of this issue.
I have followed all your guys advise and have diconnected it for the time being and I also have had no C.E.L so far I have driven it for about 45 minutes in total since disconnecting the air pump therefore it cannot be that important however I am a little concerened that it is not reporting a fault with this part disconnected as I did not get C.E.L error when my IC pump went last year...So I would appreciate if someone can confirm if the CEL would occur if the Air Filter is disconnected

Thanks

Eleventeen

It will come on. It usually takes a few drive cycles as opposed to a preset amount of time.

Eleventeen

It will come on. It usually takes a few drive cycles as opposed to a preset amount of time. The code it will initiate will be a P0410 and there will be absolutely no difference in performance.

pointman

Wait wait... isn't that electric noise normal after shutting the car down.. for a few minutes at least???