Anyone in an emissions-required state removed air pump... - PeachParts Mercedes-Benz Forum

crs82 · #1 09-23-2011, 04:12 PM

on a M103 engine?
I'm thinking about removing the smog pump, putting on a shorter belt and calling it a day. Has anyone done this and passed emissions.
Same with EGR, anyone deleted their EGR with no ill effects?

tbomachines · #2 09-23-2011, 04:32 PM

IIRC Since the smog pump is only active on cold starts I'd imagine that emissions would be okay without it assuming you get it tested warm, but of course do so at your own risk...I'm sure other members will chime in.

IYAAYAS · #3 09-23-2011, 06:21 PM

I have seen on here that you can remove the magnetic part of the pulley so the visual check will still pass. It's an older post (page 2-4). I do not require emissions test here so the previous owner of my 95 E320 removed it completely. Make sure you get the right size belt or you will have belt squealing like I do.
A hard lesson I learned ... DO NOT PUT ANYTHING ON THE BELT TO TRY TO STOP THE SQUEALING! my pulleys were all kinds of gummed up and it took hours to clean them.

JohnM. · #4 09-23-2011, 06:53 PM

It's an equal amount of work to remove the smog pump, get proper sized freeze plugs into the lines, get delete plate for EGR valve, and buy a shorter belt, as it is to just replace it with another used one, or reman'd. And then have to worry about visual inspection. Just depends on how thorough your state is. Here in Colorado they don't even look under the hood but to make sure there's an engine in there, yep. Also make sure to write down the shorter belt part number and keep it in the car somewhere in case you ever break down. Removing it won't affect warm emissions on the car, only the first few minutes of cold start.

crs82 · #5 09-24-2011, 11:19 AM

As far as I can tell, the pump seems to be working. I was just thinking of getting rid of unnecessary equipment and cleaning up the bay. Less equipment to inevitably go bad and cause problems.
Does this deletion require the old style bearing bracket for the fan?
The reason for the EGR delete is that when I checked it by pulling vacuum on the hose, I could see the little piston go in and out and it would not hold vacuum. Pulling vacuum also did nothing to engine idle, it still ran smooth (minus bearing bracket racket). I could get behind deleting it, if I was reasonably sure it would not hurt my already marginal emissions.

compu_85 · #6 09-26-2011, 12:43 PM

Leave it in place. It lowers warm up emissions a bunch, and doesn't use any power when it's not active.

-J

tbomachines · #7 09-26-2011, 02:57 PM

I read somewhere that they have a fairly high failure rate, I believe in either the bearing or the clutch. I never had an issue on mine...IMO if its spinning its fine

JohnM. · #8 09-26-2011, 05:51 PM

Quote:

Originally Posted by tbomachines

I read somewhere that they have a fairly high failure rate, I believe in either the bearing or the clutch. I never had an issue on mine...IMO if its spinning its fine

The failure rate is no more than any other accessory with a pulley.

S-Class Guru · #9 09-26-2011, 07:37 PM

The air pump electrical connector can be unplugged, and the vacuum line to the one-way air valve can be plugged, and the pulley will just spin on the idler bearing. This bearing will go out every 10-12 years, but is pretty easy and cheap to replace. This approach is one way to permanently deal with a failing emissions pump. As stated, will not effect emissions cause they test with a warm engine. But, you are technically in violation of the emission law.

The EGR valve is another story; it should be functioning to help maintain factory fuel mixture settings and lower combustion chamber temps at cruise RPM. You might get ping in hot weather if it's not functioning. The EGR actually does not open at the emission test speeds used in Texas (12 MPH & 22 MPH i think), so it does not come into play during the test. The common failure modes I have seen are the pintle not moving when you apply vacuum to the nipple (ruptured diaphragm), or a clogged passage where
the EGR pipe enters the underside of the intake manifold. Both will have the same effect - no change in idle when vacuum is applied to the EGR. If it is functioning and the pipe is clear the idle will change very noticeably when vacuum is applied.

DG