Hello,
I would like some help, concerning the vacuum system of a 1989 w124 300 turbodiesel.

Its like this: I put a OM603turbo in my 1986 w201 2.3-16valve gasser.
The engine already starts and runs, but at the moment i am connecting the vacuum system.
The folwoing i have found out:
-the vacuum pot on the InjPump that shuts the engine of
-the electric red thing at the end of the IP, which PROBABLY is enrichment at cold starts (sort of a choke, lets the engine rev a bit higher stationary)
-the ALDA thing (What exactly is ALDA? Is it enrichment for when there is turboboost available? more cc diesel injected? That way more power?)

But now my question: on the SIDE of the IP, there is bolted on a cornery thing, with some vacuumhose-attachements on it. The cornery thing is about the size of a pack of cigarettes, and it has a date (of manufactury?) stamped into it. On this engine (which came out of a 1989 car) the date on the part is 1994, and the part number begins with 140 (90's S-class)


Another question: On the drivers side fender there is a BLUE vacuum pot mounted, which is connected with some hoses to the engine, and also nearby (and connected to the ALDA, and the blue pot) a electric solenoid, with vacuum hoses and a 2-wire plug.
What are these for?

NOTE: this is a European car, so no exhaust stuff like trap oxidizers or other environmental stuff.

PLEASE your help!!


Have been searching here, and found out that the blue pot is an amplifier for automatic tranny. I coupled the OM603 to a getrag manual box, so i suppose i can throw the blue pot in the dustbin?

Electric solenoid on the inner fender wall is a thing that operates when the boost is to high (stuck wastegate) ????????????????? Is this true??????????

Electric sensor in the inlet manifold is the thing that drives the overboost solenoid????????? is this true?????


If all this is true, I only have one question left, and that is what is the thing that is mounted on the SIDE OF THE INJ.PUMP?????


Been searching a bit more, and it seems that this part is named a Vacuum Control Valve. And that its mainly for an Automatic trans????? True????

If so, can I throw this also in the dustbin since i dont have an Automatic trans?

Yep, that blue flying saucer is a vacuum amplifier for an automatic, so you can bin it.

The electric solenoid on the inner fenderwell is most probably the solenoid that softens the cold shifts. It would be sitting right next to the vacuum amplifier mentioned above. The "overboost protection valve" is the item that you are referring to that protects the engine from a stuck wastegate. It's located, typically, on the firewall directly in front of the driver. But, that vehicle might be different.

This is true.

If it's a plastic bodied affair, near the top of the IP and has a couple of vacuum hoses coming from it, then it's the vacuum control valve for the automatic and you can just ignore it.......or remove it.

Thank you Brian!
Everything is clear now, you've answered all my questions!

if you would excuse me now, i have to take out the trash