Assuming the sender and gauge are a matched set, that seems high for cruising. 82-85*C is what I expect. Is it fully bled? Remove a temp sensor by the upper hose fitting to be sure.

Sixto
87 300D

Does your fan clutch work?

-J

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Will do. I'll check that for sure...

__________________
1987 300SDL #1, 1987 300SDL #2, 1980 240D, 1982 300SD, 1994 S350, 1990 350SDL, 1991 350SD, 1985 300D, 2005 E320CDI

Gone, but not forgotten: 1981 300SD, 1982 300SD, 1987 300SDL, 1983 300TD, 1980 300CD, 1981 300SD #2, 1987 300D, 1987 300TDT, 1980 300D

AFAIK Yes.

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1987 300SDL #1, 1987 300SDL #2, 1980 240D, 1982 300SD, 1994 S350, 1990 350SDL, 1991 350SD, 1985 300D, 2005 E320CDI

Gone, but not forgotten: 1981 300SD, 1982 300SD, 1987 300SDL, 1983 300TD, 1980 300CD, 1981 300SD #2, 1987 300D, 1987 300TDT, 1980 300D

A member in another forum had this advice to get the turbo spooling. Would this work on the OM603?

Just directly plumb the boost line from the manifold to the ALDA on the injection pump. The bypass is for overboost situations that never really arise. Your wastegate is boost actuated. Until and unless you find some way to mechanically increase the fueling (big $) for the engine, I wouldn't bother trying to tweak the turbo boost output.

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1987 300SDL #1, 1987 300SDL #2, 1980 240D, 1982 300SD, 1994 S350, 1990 350SDL, 1991 350SD, 1985 300D, 2005 E320CDI

Gone, but not forgotten: 1981 300SD, 1982 300SD, 1987 300SDL, 1983 300TD, 1980 300CD, 1981 300SD #2, 1987 300D, 1987 300TDT, 1980 300D

That's how I have my car set up currently - though I also have boost going to the vacuum amplifier on the wheelhouse for transmission shift firmness. Your 86 would have had this, I don't know if the W140 does.

-J

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

I agree that it's unlikely you'll need the overboost circuit so I vote for you to proceed as advised. The 603.971 line from the manifold to the ALDA doesn't go through an overboost valve since the ECU controls boost through the vacuum actuator. The ALDA line branches to a MAP sensor. The MAP sensor isn't needed if you have a pressure actuator so all you need is a line between the manifold and ALDA. If you have a vacuum actuator and the ALDA line is clear, something's telling the ECU to not allow boost. Did you disable the EGR system?

Which turbo is on the engine; the one the car came with or the one the engine came with? The turbo the car came with has a vacuum actuator unless it was converted. If it has a vacuum actuator, run a vacuum line directly from the vacuum pump to the actuator for testing only. This will peg the wastegate closed. Test the car to see if you feel boost but don't overdo it lest you blow something.

I don't think the 140.134 has a transmission vacuum amplifier.

Sixto
87 300D

I rebuilt the turbo that was on the W140. So, you are saying I will be at full boost to verify it works by running the lines as you suggested for testing?

__________________
1987 300SDL #1, 1987 300SDL #2, 1980 240D, 1982 300SD, 1994 S350, 1990 350SDL, 1991 350SD, 1985 300D, 2005 E320CDI

Gone, but not forgotten: 1981 300SD, 1982 300SD, 1987 300SDL, 1983 300TD, 1980 300CD, 1981 300SD #2, 1987 300D, 1987 300TDT, 1980 300D

Hooking up the vacuum actuator directly to a vacuum source will allow full boost and then some all the time. It's up to your right foot to keep the engine healthy.

It's a pity you did all that work to the turbo and didn't swap in a pressure actuator. IIRC the actuator in a 603.971 is inconveniently located for in-situ retrofit. Maybe if you remove the alternator...

Sixto
87 300D

NOW you tell me... haha. Thanks for your help and advice yet again.

__________________
1987 300SDL #1, 1987 300SDL #2, 1980 240D, 1982 300SD, 1994 S350, 1990 350SDL, 1991 350SD, 1985 300D, 2005 E320CDI

Gone, but not forgotten: 1981 300SD, 1982 300SD, 1987 300SDL, 1983 300TD, 1980 300CD, 1981 300SD #2, 1987 300D, 1987 300TDT, 1980 300D

Wait. You've been driving a 140 with a 3.0L powerplant, with no boost...? Yikes! That power/weight ratio must be almost 240D-ish.

__________________
Dave
Boise, ID
Check out my website photos, documents, and movies!

Actually, as an owner of a 240D automatic, the boostless W140 3.0L still would blow past it. But, the black smoke piling out of the rear from the cranked up IP AND no boost... The 240D wins there. haha

__________________
1987 300SDL #1, 1987 300SDL #2, 1980 240D, 1982 300SD, 1994 S350, 1990 350SDL, 1991 350SD, 1985 300D, 2005 E320CDI

Gone, but not forgotten: 1981 300SD, 1982 300SD, 1987 300SDL, 1983 300TD, 1980 300CD, 1981 300SD #2, 1987 300D, 1987 300TDT, 1980 300D

Well there's no reason the W140's computer can't control the vacuum wastegate on a 3.0. I'd just hook everything back up as it was.

-J

__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Well, actually I transplanted the W140 turbo onto the 3.0L engine. It had a slightly larger trim, and it fit much better (being OE to the W140). I rebuilt the center section while it was off. So yeah, hopefully it will work seeing its the same turbo the car had before.

__________________
1987 300SDL #1, 1987 300SDL #2, 1980 240D, 1982 300SD, 1994 S350, 1990 350SDL, 1991 350SD, 1985 300D, 2005 E320CDI

Gone, but not forgotten: 1981 300SD, 1982 300SD, 1987 300SDL, 1983 300TD, 1980 300CD, 1981 300SD #2, 1987 300D, 1987 300TDT, 1980 300D

Well, started to try to run vacuum lines. The 2 vacuum transducers located behind the passenger headlight will not hold vacuum or pressure. I took the video below to demonstrate the sounds they make under vacuum and pressure. First was vacuum which was a sputtering noise. Then just a hiss when blowing into the line. It is normal for these parts to not hold vacuum? Just dont want to start throwing money at the car. Also, the brake booster check valve side tap nipple was broken off, so I've been trying to run vacuum from the nipple on the vacuum pump. So far, I cannot get the car to shut off. I can manually suck air out of the shutoff valve solenoid hose, and the engine dies immediately. But, the key shutoff switchover is allowing vacuum through it in any key position. I checked with a test light, and it is getting power in one key position, and dead in the other. I'm thinking its bad, but also wanting to double check before purchasing. I cant find a part number on it to check a price. Anyway, below is the video of the noises the vacuum transducers are making under vacuum and pressure.

Thanks!

Vacuum Sucks

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1987 300SDL #1, 1987 300SDL #2, 1980 240D, 1982 300SD, 1994 S350, 1990 350SDL, 1991 350SD, 1985 300D, 2005 E320CDI

Gone, but not forgotten: 1981 300SD, 1982 300SD, 1987 300SDL, 1983 300TD, 1980 300CD, 1981 300SD #2, 1987 300D, 1987 300TDT, 1980 300D