The Black Rubber hose in the picture,to the right of the arrow,whose visible
end is plugged onto the Pressure operated waste-gate actuator's nipple.
Where is the other end of that hose ?
Is it Plugged into or onto anything?

Thanks?

Attached Thumbnails

 

__________________
'84 300SD sold
124.128

Can you make out anything from this pic?

Attached Thumbnails

 

The hose is plumbed from the Compressor Housing to the Pressure Operated
Waste-gate actuator.Allowing the Boost Pressure to force the Wast-gate open
WHEN Boost gets too high.If there are no breaks/leaks in the Hose/fittings
it'll work as designed.

I HAVE No Idea what the Mystery nipple in that device on the compressor
housing is (?)
BUT if it's meant to feed pressure info to something like the ALDA
(Fuel/Barometic enrichment controller for the Injection Pump) AND
it's left disconnected all your Boost will escape from it.

You need another 126.135 owner to guide you further.

Hopefully one will chime in ,soon.

__________________
'84 300SD sold
124.128

Thanks! I may just swap out compressor housings.

Are you "86" ing the original Turbocharger ?

You do know you can obtain a "Cartridge" and rebuild your own?

Or if the bushings (used before Turbo Manufacturers went to roller bearings) are O.K.
a Seal Kit can be installed in a couple of days.
AND instructions are all over the Web.

__________________
'84 300SD sold
124.128

Lets say the "Mystery Device" is a Boost Control "Pop Off Device" and is
meant to be plumbed to the Pressurized Intake manifold.
AND when boost pressure reaches dangerous levels it somehow
allows the HOSE we see to transmit the Boost to the Actuator.

Mercedes is known for engineering things simply because they can.

I gots nothing else.

__________________
'84 300SD sold
124.128

Well, I put in a "rebuild" kit in it. Ended up blowing oil out the exhaust shortly thereafter. A cartridge is more than I want to spend on a 5th vehicle that I don't really need. Turbo shop wants the same to rebuild it. Used was the best choice for me. I might would spend the extra if I had a 3.0 short block to go in the car.

Sorry, I couldn't help you quicker.

M.C.

__________________
'84 300SD sold
124.128

Your help is most appreciated. Merry Christmas!

That's a turbo from a 603.96 (86-87 SDL/D/TD) with ARV. The 603.970 in the 90-91 350SD/L didn't have ARV. There's no need to hook up ARV which IIRC is there to assist the trap oxidizer. Does the hose from the 350 air cleaner even hook up to that turbo? IIRC you can't just swap compressor housings to be rid of ARV since the 55 trim compressor in the 350 is bigger than the 50 trim compressor in the 300.

ARV gets a vacuum signal from the 'stuff' under the air cleaner as does EGR. Under specific circumstances, vacuum applied to the ARV opens a port that bleeds charge air from the compressor outlet to the compressor inlet. It's most definitely an emissions device rather than a performance device. The ARV in my SDL had a deformed plunger so there was a persistent boost leak even after the vacuum signal to the ARV was mysteriously disabled. I removed the ARV housing - no gasket to worry about - and set a freeze plug into the compressor outlet port to seal it. The port into the compressor inlet is an odd shape I couldn't easily seal so I left the ARV housing in place to keep it sealed.

You should have no problem running the 50 trim in the 350. It might seem peppier off the line with boost building sooner at the cost of less top end when the 50 trim runs out of breath. That's conjecture.

Sixto
MB-less

Nothing connects to the turbo from the air cleaner except the large air inlet pipe coming from the "box" under the air filter housing. Air comes into the air filter housing and flows downward through the box into the large pipe that connects to the compressor housing inlet. I've found nothing that would connect to this little "nipple."

That's the hose I suspect won't be a clean fit on the compressor inlet. My faded memory says the flange ends 20-30mm forward and is a few mm smaller. Your 350 won't have a vacuum amplifier nor an EDS signal to use ARV (not that you'd want to). You can use the turbo as is with ARV disconnected but I'd look into obtaining the correct turbo for your car. IMO, that one ain't it.

Sixto
MB-less

Could I just swap out the compressor housings? AFAIK the only difference is one has an ARV and the other doesn't.

Is this turbo from a newer 350 and would using it create more EGT'S? Less? This turbo supposedly came from another '91 350SDL.

You can try but I'll bet it won't work. Here are pictures from when I compared a 603.960 (87 300D/TD) 50 trim compressor housing to a 603.971 (92-95 SD) 55 trim compressor housing:

50 trim wheel in 50 trim compressor housing -



55 trim wheel in 50 trim compressor housing -



In your case you'd be fitting a 55 trim housing or a 50 trim wheel. It'll fit but you won't build much boost. As for the air inlet hose fitting properly:

Profile of 50 trim (left) and 55 trim (right) compressor housings -



I don't have clean pictures of the compressor inlet flanges. You'll have to measure those yourself.

You can see the ARV bleed port in the compressor outlet in the second and third pictures.

Sixto
MB-less

Thanks for the visuals Sixto! So the turbo, while not the stock turbo for a '91, will work in my car giving me more boost off the line but not so much when I'm at cruising speed. Correct? It's gonna take me longer to reach 120 mph with this turbo than the original. Correct? LOL!