That "thing" on the turbo looks like an air recirculation valve. Is your turbo a Garrett or a KKK? I don't see the boost actuator is why I ask. The 126FSM shows the ARV for 1987+ vehicles but doesn't show a vacuum wastegate. Mine's an '86 Federal with the Garrett turbo, so no emissions equipment and not a good comparison.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

I don't know. I can't even see the turbo much at all, but it looks different than the Garrett T3 that's on my car.

__________________
Stop paying for animal enslavement, cruelty, and slaughter. Save your health and the planet. Go vegan! I did 18 years ago. https://challenge22.com/

DON'T MESS WITH MY MERCEDES!


1967 W110 Universal Wagon, Euro, Turbo Diesel, Tail Fins, 4 Speed Manual Column Shift, A/C
1980 W116 300SD Turbo Diesel, DB479 Walnut Brown, Sunroof, Highly Optioned, 350,000+ Miles

I can't see the wastegate either so crowded in there but I'm betting that's your power problem .

You alls keep saying "vacuum" when talking about the wastegate, it works off _PRESSURE_, completely different .

? Have you yet tried a small, cheapo boost gauge to see what the actual boost levels and RPM's are ? .

I bought a 1" 'Mr Gasket' (cheapo Chinese brand) $20 fuel pressure gauge for boost testing my my grey market 300TD, it only goes to 15# so it's very sensitive, easy to connect using simple vacuum hose and a plastic 'T' , it would let you know what's going on in your engine boost wise right away ....

I'm trying to remember what FLAPS I bought the gauge at, prolly an O'Rielly as they're my go to place for cheaper filters and basics .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

In a normal world, yes. In the 90s German car world, no. At some point in the early 90s, they migrated to a VACUUM operated wastegate actuator that's controlled by the ECU instead of the pressure operated wastegate that is passively operated off the intake manifold pressure. The 124's got it for sure, the 140's had it, but not sure if it was ever fitted to the 126 (hopefully not).


The ARV should be disabled when vacuum is not applied to it, but it could possibly be stuck partially open. If so, boost is bleeding off back into the atmospheric side of the compressor housing, more or less defeating the purpose of the turbo. Checking boost pressure will tell you a lot real fast. Put a T on the ALDA sense line and tie in a pressure gauge and go for a ride.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]