300d Loss of power? - Mercedes-Benz Forum

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post #1 of 4 (permalink) Old 03-17-2015, 06:54 PM Thread Starter
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Date registered: May 2014
Vehicle: 1982 300D Turbo Diesel
Location: Phoenix, AZ
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300d Loss of power?


So my 1982 300d turbo diesel broke down about two weeks ago because my water pump leaked out all my coolant and overheated my engine.

Well last week was spent replacing radiator hoses and my water pump, along with degreasing my engine (it was really bad).

Anyways, everything was finalized yesterday when we turned the ignition and started it up. HOWEVER, three new problems seem to have arisin today after putting the front of my engine back together.

It seems like there has been a major loss of power at lower speeds. Before i was able to drag race people from a stop light, but it now it seems to struggle getting up to 30. Also, when i finally do get to 30, it has extreme issues switching to the next gear. It takes all the way up until about 45mph to finally switch up to the next gear. I cannot get the car to go more than 70mph. Wheras before i could get up to 85 easy.

Keep in mind, this is when i have my foot pressed down. If i gingerly press down on the pedal from a stop, it seems to shift a tad better, but only a very little bit...any suggestions? Did i put the car back together wrong?

I have also noticed now that the engine does not shut off when i take the key out. I have to manually shut it down from inside the hood.

Also, i just took off the banjo line and gave the bolt and the line itself a really good cleaning...which didnt help. It literally feels like the engine is throwing up rpms but not putting the power to the ground...if that makes any sense. I noticed as well thqt there is a line missing from the black four-way rubber connector thing near the alda on the right side of the engine. The line that is missing is the one going towards the engine itself.

Sorry for the really long post! And i really dont know much about cars, so any simplified help is appreciated. Thank you in advance(:
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post #2 of 4 (permalink) Old 03-18-2015, 07:47 AM
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the fact that you cannot turn engine off with key shows that you have no vacuum , so , take a close look at the lines by the oil filter , one is popped off .this will also affect the transmission shifting .driving at 85 is nut .
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post #3 of 4 (permalink) Old 03-23-2015, 08:07 AM
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Definitely a Vacuum leak somewhere. Use a hand pump tester and test the vacuum pump to see if that is in need of replacement. Much more likely that a vacuum line has been knocked out (shutoff valve, cruise control, climate control or door locks). That's the 4 way rubber connector you see holding all the lines together. You need to find the line and reconnect it. The only other thing that would be causing loss in power would be a dying turbo charger.

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Last edited by Shakedown Street; 03-23-2015 at 08:21 AM.
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post #4 of 4 (permalink) Old 03-23-2015, 08:36 PM Thread Starter
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Date registered: May 2014
Vehicle: 1982 300D Turbo Diesel
Location: Phoenix, AZ
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Thank you guys for the replies! Unfortunately i have been working quite a bit lately so i have not had time to work on anything myself. I ended up taking it to a Euro specialist down the street, and sure enough, most of my vacuum lines were out of whack...either missing or routed wrong. After they fixed all of that up and replaced my injection hoses, everything works great! except for my door locks, which will get sorted out eventually.

But again, thank you guys, i really appreciate it XD
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