Air pump question (smog pump) '90 300SE - PeachParts Mercedes-Benz Forum

Hit Man X · #1 11-28-2008, 03:55 AM

I simply removed it on my '90. Went to the '86-89 M103 brackets, it all bolts up. You just need the '86-89 fan bearing bracket and of course the alt bracket itself. I did the extra to just tidy up the engine bay.

You could always just remove the air pump and short belt it.

I believe it is an attempt to help with excessive cold start emissions (quicker converter light off, my F150 had this along with most Small Fords of the era), don't forget MB also added EGR on the '90+ cars...

pawoSD · #2 11-28-2008, 10:11 AM

Quote:

Originally Posted by Hit Man X

I simply removed it on my '90. Went to the '86-89 M103 brackets, it all bolts up. You just need the '86-89 fan bearing bracket and of course the alt bracket itself. I did the extra to just tidy up the engine bay.

You could always just remove the air pump and short belt it.

I believe it is an attempt to help with excessive cold start emissions (quicker converter light off, my F150 had this along with most Small Fords of the era), don't forget MB also added EGR on the '90+ cars...

Awesome to know that! I know what I'll be doing now if her car's air pump bites the dust.

tinypanzer · #3 11-28-2008, 08:15 PM

Yes, that is excellent to know. I might just do that to clean up things and make some room in there.

One more thing to scout for at pick 'n pull.

Hit Man X · #4 11-28-2008, 09:04 PM

Don't forget to check the dipstick o-rings, those are vac leaks too...

pawoSD · #5 02-22-2009, 12:53 AM

Quote:

Originally Posted by Hit Man X

I simply removed it on my '90. Went to the '86-89 M103 brackets, it all bolts up. You just need the '86-89 fan bearing bracket and of course the alt bracket itself. I did the extra to just tidy up the engine bay.

You could always just remove the air pump and short belt it.

I believe it is an attempt to help with excessive cold start emissions (quicker converter light off, my F150 had this along with most Small Fords of the era), don't forget MB also added EGR on the '90+ cars...

So you can remove the air pump and just put in a shorter belt? Leaving everything else the same? Or do you need to swap other stuff too?

pawoSD · #6 02-22-2009, 10:27 AM

Does anyone know? I'd like to get the appropriate stuff ordered so I can get to work on fixin' up the 300E....

S-Class Guru · #7 02-22-2009, 10:52 AM

Well, I haven't tried the short-belt approach.
I just unplugged the pump about 10 years ago - and also plugged the vacuum line to the valve. That way, the valve will stay closed all the time. There is a 1-way check valve in the air line also, but why not help it out. Ig the 1-way failed, exhaust gas would reverse-flow up into the pump.

Also, the idler bearing in the pump is replaceable for not too much money, and easy to do. So, leaving the belt on the pump, just turning the idler bearing is a good option.

DG

pawoSD · #8 02-22-2009, 03:17 PM

Our air pump still seems to work smoothly, so I think I might just replace the belt and idler pulley for now (and inspect everything else for play) and see how it goes....if the pump gets noisy I will unplug it.....