Howdy

I own a 1985 300d turbodiesel with the California emissions system.

It seems that my turbo will not kick in and I have been told the turbo looks good and it could be one of the controller or the regulator. The third possibility is the "catalytic converter". Does this sound right?

Dave

Check the boost control line coming of the banjo bolt at the back of the intake manifold. That line can get plugged up or unattached. If either happens, no boost.

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1977 300d 70k--sold 08
1985 300TD 185k+
1984 307d 126k--sold 8/03
1985 409d 65k--sold 06
1984 300SD 315k--daughter's car
1979 300SD 122k--sold 2/11
1999 Fuso FG Expedition Camper
1993 GMC Sierra 6.5 TD 4x4
1982 Bluebird Wanderlodge CAT 3208--Sold 2/13

More correctly, no power from the boost. The boost will be present, but the additional fuel will not be, resulting in low power.

Try spinning the turbo (when the engine is cold) if it spins freely it should be producing boost, then check the banjo bolt and boost line for plugs or leaks. When I got my '85 Cali the boost signal line from the maifold had come loose from the "blue flying saucer" on the driver's side fender producing the same effect you are having.

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

More correctly, no power from partial boost. The engine can't make any significant boost without fuel. But, without a bit of boost, it can't get the fuel.

It's a bit of a catch-22.

Excellent Point!

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

Can you tell me how do you "spinning the turbo".
Thank you

Take the U tube off from the ait filter to the turbo. By freely they mean like swimming in water not like a slip and slide.

__________________
http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

Yep, just pull the accordion like tube from the air filter off the turbo, stick your fingers into the turbo inlet (engine OFF!!!!!) and give it a gentle spin. It should rotate easily and continue spinning for a second when you release it.

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

Thanks all

Just wish I knew enough to return the favor

Wagonhorse

As you do more things, you will ask more questions. Then as your experience grows you will be able to help other people that are just starting out. Paying it foward is what we do here. I still say this is the BEST MB forum I have seen.

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RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

One of the best forums period. I have yet to put on my flame suit except for oil discussions

__________________
http://superturbodiesel.com/images/sig.04.10.jpg
1995 E420 Schwarz
1995 E300 Weiss
#1987 300D Sturmmachine
#1991 300D Nearly Perfect
#1994 E320 Cabriolet
#1995 E320 Touring
#1985 300D Sedan
OBK #42

Also make sure there are no cracks in the wastegate hose, the smaller rubber tube from the front/compressor side of the turbo to the valve underneath. Not likely to be the complete answer, but a leak here will vent boost pressure that shouldn't be vented.

Actually, the opposite of what you would expect will happen. The leakage from the wastegate hose (or the removal of the hose) causes a negligible loss of air to the engine. It does, however, cause the wastegate to open at a later boost pressure...........or not open at all.........with significantly higher boost pressure.

So, cracks in the wastegate hose, or a missing wastegate hose will only cause greater boost.

Yep, what Brian said. A cracked hose will not let the waste gate open because of the bleed off from the hose itself leaks enough that the pressure cannot overcome the resistance of the spring holding the wastegate closed.

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

Clue me in here, Brian and RRG. Are you saying the aperture of the wastegate hose is so small, compared to the compressor/intake manifold aperture, that even if the wastegate hose is fully vented to the atmosphere, it will not meaningfully reduce the boost from the compressor? (Ignore for the moment the function of the wastegate valve.)