Diesel Engine Specific Aid

91 350SD smoke and miss

91 350 SD smoke and miss at start

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A recently purchased 91 350SD inline 6, 3.4 turbo with 162K.

Car smokes and misses at startup. The car was always warmed up when testing and checking prior to purchase... you know the story. I'm trying to solve the inherited issue with little luck. Otherwise aside from a couple small issues, it's a jewel.

Sometimes it smooths out and runs like silk with no smoke, other times symptoms persist. As it warms up and smokes it makes an occasional sound like a small dog sneezing as it misses, sorry thats the only sound I can relate it to.

Chassis Model Number

W126

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Diesel Engine Specific Aid

77 300D Engine Transplant options

recently, my 1977 300D W123 diesel engine seized. Ive come across a 1984 300SD turbo Diesel W126. Can I transplant the turbo Diesel complete into my 1977 w123. I planned to transplant the engine, transmission, and rear axel.
Will this work? The reason Why I ask is because I am not sure if there is any wiring, or vacuum lines that wont interchange, or need to be added. Please advise. Thank you for taking time to help.

Chassis Model Number

W123

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Diesel Engine Specific Aid

Proper compression for 92 300D?

Hello everyone,
just wondered what proper compression is for a diesel. I have a 92 300D, and my shop recently did a cold compression test with the following numbers- #1-340, #2-330, #3-290, #4-320, #5-320.
He said that these were pretty good for a car w/ 270k- I just wondered what anyone else thought. The car seems to start fine, and runs well.
Thanks!

Chassis Model Number

W124

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Diesel Engine Specific Aid

1984 300D Decrease in mileage

My Benz "Old Yella" had recently slipped a little in the miles per gallon dept. I have developed an obsession with the car and stay right on top of things mechanically so I was a little puzzled. The air filter was coming up on my periodic maintainence schedule so I decided on trying out a K+N. I usually change air filters after about 20,000 miles of use. This figure is flexible as all driving conditions are not the same. Dust, road salt and sand can all gather in the filter and constrict air flow which is essential to internal combustion engines.

Chassis Model Number

W123

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Diesel Engine Specific Aid

77 300D engine turns slow - wont fire up

I own a 1977 300D. I was driving home one day and I noticed when I arrived to Traffic lights the car acted like it wanted to shut off. I resumed driving and as I was getting close to my home, the car shut off. Since then I have replaced the battery, replaced the starter all with no luck. On a fully charged battery the engine turns slow, and acts like it want to start but then dies. Upon a second attemtp at starting, the engine gives me a click, and the engine does not turn! I am super confused. can anyone help?
thank you in advance!

Chassis Model Number

W123

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Diesel Engine Specific Aid

82 240d compression test results

Just completed a compression check on my high mileage 240d.
#1 120/200
#2 180/320
#3 190/340
#4 180/320

Number one is not looking so great. The test was completed with the engine cold. I did try adding oil and the change was marginal 130/220 on number one.
The engine runs smooth with little smoke at start up. What my next step? Pull the head and have a look at the valves?
Thanks for your imput.
The compression tester and booklet were excellent.

Chassis Model Number

W123

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Diesel Engine Specific Aid

1979 300d Turn Signal Relay

Hey everyone,
I cannot for the life of me find the turn signal relay on my 1979 300D. My left signal flashes twice as fast as the right one and the bulb in front is very weak while the rear one is bright. Both bulbs are brand new and all the connections look good. I also replaced the hazard button on the console and the problem remains.
I have the new turn signal relay from mercedessource but I can't find where it goes. It definitely doesn't go under the console like some of the posts I've read and it doesn't seem to be anywhere under the drivers side dash. I traced the wiring from the steering column to one relay but its a much larger 8 or 9 pin and that seems to be the only relay under there that the turn signal wiring goes through.

Chassis Model Number

W123

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Diesel Engine Specific Aid

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