1985 300CD

I pulled the EGR off the engine and added the two blocking plates. The intake port was filled with very wet black soot, but no sludge and not plugged.

I pulled the vacuum line from the Air Valve and plugged the fitting at the valve.
I then took the vacuum line from the EGR and simply connected it to the line that I pulled from the ARV and tie wrapped them off to the side.

The car actually seemed a bit slower from a dead start in D, until the turbo spooled up. Other than that, the engine runs great. No smoke unless you stomp on it. Idles great.

1. Is this the proper way to deal with the vacuum lines?
2. Do people actually remove the ARV from the car or just plug it as I have done.
3. If removed, is there a hole to plug on the engine?
4. Should I now mess with the ALDA or leave it alone? I'd love to improve the throttle response and give it some more umph if possible.

Thanks. This is my first stinker and I'm a bit like Forrest Gump.

You might as well just remove those vacuum lines completely. All they are is one more source for a leak in the future. For the ARV, the best thing to do is take the cover off and shim it with something like pennies or a nut so the ARV 100% stays closed. Removing it would be weird, since you'd have to come up with a way to block everything. Better to find a turbo from an earlier car if you want it looking clean.

You can play with the ALDA if you want. Just realize that inside it is a thin metal disc that the stud is attached to, so if you get too crazy turning that stud it'll snap off. Like with all things, if you feel resistance, stop. But every engine/altitude is different. some people turn it 1/32 out and suddenly they have black smoke a mile wide. I turned mine all the way out and all I got was better acceleration. Ended up removing mine completely and it's fine.

And, of course, the FSM says...



-Rog

Thanks for that explanation Rog.

Is there a trick to removing the little black cap on the ALDA or do you just use a pick and dig it out?

Before touching the ALDA, remove it as a unit (mind the washers!) then go for a drive. That's the maximum benefit you can expect. If that doesn't do it for you, don't tamper with the original ALDA setting just yet.

Sixto
83 300SD
98 E320 wagon

OK great. Thanks for the info. I will do a search and learn about its removal (and the washers) before I get cro-mag with it.

Not much to it. The ALDA has a threaded base held to the IP by a nut captive to the IP that takes a 24- or 27mm wrench. There are wrench flats on the bottom side of the ALDA which require a wrench so thin that I instead hold the ALDA case itself with a strap wrench or padded channel locking pliers. There are a couple of copper washers of precise thickness installed at the IP factory. An alternative to adjusting the ALDA set screw is getting different thickness washers but I understand they're crazy expensive and possibly only available from Bosch, not from MB. The IP should not leak oil with the ALDA removed but you might shield the exposed plunger from dirt which could get into the IP when you install the ALDA.

Sixto
83 300SD
98 E320 wagon