W126, BENZ AID - COMMON QUESTIONS AND ANSWERS

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

Forums

Diesel Engine Specific Aid

1984 300D turbo cabin heat inconsistent

Hi all and thanks to Mercedessource for all the help getting "Old Yella" back to nearly original shape. My question concerns the heat in my old girl. I replaced the monovalve some time ago and it had the typical tear in the rubber portion of the valve. The replacement gave me heat, though intermitently. Now the heat will roast you but if I am on the road a while it will subside and eventually I will feel cool air coming out of the vents. Then the heat will come back and the cycle starts over again. Roast then cool.

Chassis Model Number

W123

Forums

Body and Interior 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

Forums

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

Forums

Diesel Engine Specific Aid

Blower Motor 1985 300SD Turbo Diesel

n/a
Can anyone out there direct me to the location of any relays or inline fuses that might be the cause of my blower motor not working. I know the blower motor works having run 12 volts directly to it. Additionally, I have no power when checking the motor leads with a volt meter when everything is hooked up. I originally thought the problem was in the block or coil resister beneath the master cylinder/vacuum booster. Changed out both resisters and still no power to the motor. The fuse looks good (number 11, I think in the fuse box compartment.)

Forums

Body and Interior Specific Aid

Best transmission/model for towing

I have been using my 1980 300sd to pull a small enclosed trailer (w/ nosecone, 1000 - 1500 lbs). I have had no problems with the transmission whatsoever doing this for the past 80 thousand (163,000-241,000) miles running on veg, but this vehicle was just totaled by an suv so I am looking for a replacement.
I would like to have a wagon for the extra space but I'm worried about putting too much strain on the transmission. I'm also wondering if the SLS will be a good or bad thing. I was hoping it would be good as the 300sd tended to sag a little with 100lbs on the hitch.

Forums

Transmission / Suspension Specific Aid

86 300SDL grasping at straws here

I am having a meltdown here all the usual suspects are rounded up. My 1986 300SDL (that I have spent more time working on than driving no kidding) is a great car has me perplexed. It started and ran fine one day the next started and idled fine but gives me about 100RPM increase when I push the throttle with foot or under the hood so all the linkage is moving the way it should.

Chassis Model Number

W126

Forums

Diesel Engine Specific Aid

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