1993 300SD Turbo not working at all
Thread Starter
Junior Member
Joined: Mar 2020
Posts: 19
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From: freehold, NJ
1993 300SD, 1993 300SE (parts car)
1993 300SD Turbo not working at all
I recently purchased a 1993 300SD with 197k. It had the head replaced in 1999. I took it for a test drive and noticed right away that there was no pull whatsoever. It sort of felt like my N/A 1980 300TD when I had it. I removed the intake to the turbo and the impeller was moving at idle. I touched the center of the shaft (not the impeller) and was able to stop it from spinning with very little effort with a piece of cardboard. I hooked up a boost gauge and nothing. It didn't budge. I hooked it up to several different areas and still nothing at all.
I just did a diesel purge and she is purring like a kitten. I also changed the fuel filters and then changed the oil. She idles better and quieter, but there is no improvement on performance. I don't hear the slightest sound of the turbo spooling up. I'm very familiar to w123, w126, and w210 diesels having had many over the years. I'm not very familiar with the OM603 though.
Can anyone recommend where to check first? Is this a common thing with the OM603 or the early W140's? Any help would be appreciate
I just did a diesel purge and she is purring like a kitten. I also changed the fuel filters and then changed the oil. She idles better and quieter, but there is no improvement on performance. I don't hear the slightest sound of the turbo spooling up. I'm very familiar to w123, w126, and w210 diesels having had many over the years. I'm not very familiar with the OM603 though.
Can anyone recommend where to check first? Is this a common thing with the OM603 or the early W140's? Any help would be appreciate
Thread Starter
Junior Member
Joined: Mar 2020
Posts: 19
Likes: 1
From: freehold, NJ
1993 300SD, 1993 300SE (parts car)
I checked a lot of the vacuum lines and a couple were rotted. I replaced them and starting testing different lines with a mighty vac and I definitely have a large leak somewhere in the system. Only a couple of the lines hold vacuum. Are there any within the spiderweb of vacuum lines that won't hold vac?
I also checked the turbo again with the car idling and it spins freely. When I put my hand over the turbo intake and rev it, I definitely feel the suction and the turbo moves faster. I took it out for a drive and still no boost. It accelerates smoothly but definitely no pull to it.
I also checked the turbo again with the car idling and it spins freely. When I put my hand over the turbo intake and rev it, I definitely feel the suction and the turbo moves faster. I took it out for a drive and still no boost. It accelerates smoothly but definitely no pull to it.
Thread Starter
Junior Member
Joined: Mar 2020
Posts: 19
Likes: 1
From: freehold, NJ
1993 300SD, 1993 300SE (parts car)
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