Secondary air pump (smog pump) C Class - PeachParts Mercedes-Benz Forum

tobybul · #1 09-14-2008, 06:58 PM

I seem to remember sometime back a topic on how to repair or check a the secondary air pump for a 94-00 C Class. I've searched but not found anything specific to this.

Has anyone successfully tried repairing their smog pump??

Will_w202 · #2 09-14-2008, 08:19 PM

What symptom caused you to feel the need to repair?

tobybul · #3 09-14-2008, 08:30 PM

Quote:

Originally Posted by Will_w202

What symptom caused you to feel the need to repair?

Its not working. Check engine confirms it on DBII scan. I realize its not a necessary part for the car to run but I thought I would look in to it at least.

Will_w202 · #4 09-14-2008, 09:00 PM

Yeah, mine would blip-whistle a few times at normal op temps at stoplights. Engine would rev up and down a little, but it did this for probably 90k miles with no other problems caused. I sold it as-is. I think the part is several hundred $$$

Gilly · #5 09-14-2008, 10:53 PM

If that's the engine-driven type (belt drive), about the only thing repairable is the clutch, which about 1/2 the time is the problem, and is I think the only available repair part for the pump.
If it is the electric motor type, never heard of anyone fixing it, but wouldn't hurt to try.
Gilly

tobybul · #6 09-15-2008, 06:38 PM

Quote:

Originally Posted by Gilly

.......... If it is the electric motor type, never heard of anyone fixing it, but wouldn't hurt to try.
Gilly

Ok, I did try today. Looks like all thats wrong is the electric motor bearing might have lacked lubrication.

I removed the smog pump from the car this weekend and examined it today. The fan was a bit hard to turn. I put a few drops of synthetic oil (used Mobil 1 differential oil

). Let it sit for a few minutes and now it twirls with no resistance. Hopefully, thats whats wrong.

If that was all it is, then theres the fix. I'll update after I put it back. See pics:

Will_w202 · #7 09-15-2008, 06:53 PM

So that's what it looks like! Like Gilly said, some of the older cars have belt-driven ones - I'm not sure if that means older 202s, or that after that 201 they became electric. Obviously your 96 is electric......and therefore independent of the belt.

Gilly · #8 09-15-2008, 08:05 PM

I think the early 202 was still a belt driven air pump, not sure when they went electric. I do know the ones with the Kompressor motor have no air pump, it uses the supercharger for that, using a divert valve.
Gilly

tobybul · #9 09-16-2008, 08:22 AM

I put back the pump last night, drove to work, check engine has not come on..... so am guessing it works

. Right after I put it on and b4 putting back the undercarriage cover, I started the engine, crawled under the car and checked if I could hear the pump run. I could not hear anything but not sure if I am suppose to.

All I know right now is that the check engine light does not come on anymore - at least not driving to work.

Update:

CEL has not come back on.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode