W116, BENZ AID - COMMON QUESTIONS AND ANSWERS

1977 280e Poor running performance

I have 1977 280e fuel injected gas engine. After many trials I have gotten it to the point that it will start and run...roughly. It back fires through the through the air cleaner when the throttle is stepped on. I have checked and the plug wiring is correct. If you slightly open the choke plate the engine evens out and runs smooth but still backfires when the throttle is cracked. I am thinking a possible vacuum problem exists although the power brakes seem to be great. Any thoughts would be great.

Chassis Model Number

W123

Forums

Gas Engine Specific Aid

1980 300D Won't Start

I replaced the starter about a month ago. The car started fine about a half dozen times and then stopped turning over altogether - not a sound when I turned the key after the glow plug light went off. Replaced the ignition switch yesterday after first having the starter tested to make sure it wasn't a dud (it wasn't). Started the car successfully five or six times without trouble, but am now having the same problem I had before: nothing when I turn the key after the glow plug light turns off. Any idea what's going on? I'm at a loss.

Chassis Model Number

W123

Forums

Diesel Engine Specific Aid

1982 300sd - intermittent heat

1982 300sd - heater blows warm for about 5 minutes then heated air turns cool. should i replace monovalve, then try solenoid that activates. turning heater to off then back on sometimes results in heat flowing again, but not always. turning car off then restarting returns heated air. i think malfunction in monovalve, but solenoid may be at fault as well. how do you diagnose which piece to replace or both? any sources for solenoid besides dealer?? i noticed you are sold out of solenoid

Chassis Model Number

W126

Forums

Body and Interior Specific Aid

1979 300TD transmission vacuum controls???

Hi all,

I've got a 1979 300TD non-turbo that isn't shifting correctly. I'd like to start out with the vaccum system, but can't seem to come up with a schematic.

I've got Kent's transmission tuning manual, but the transmission in the 1979 wagon looks to be different than any of those explicitly described in the manual, and the vacuum schematics in the appendix don't seem to match either.

I've got two questions:

What is (and how do I test) the item labeled "B" in this picture? (I assume it's the VCV)

Chassis Model Number

W123

Forums

Diesel Engine Specific Aid

86 300D run-away engine

I have a 1986 124 300sd. I was changing out the glow plugs with the glow plug reamer kit available at MercedesSource, Awesome kit everything was a breeze lots of carbon build up. The problem arose on the test drive when the car accelerated uncontrollably! Upon close inspection I noticed that two hard fuel lines had been replaced, (by the previous owner) and in working the throttle linkage noted that ever so often the linkage rubbed on the fuel lines causing the throttle to stick in the open position.

Chassis Model Number

W124

Forums

Diesel Engine Specific Aid

1981 300TD-T Lack of Power

This 300TD-T has been running on Veg for about 3 years and 12k miles, I have owned it about 5 months. The rebuilt engine has 50k miles in it. Starting two weeks ago, the wife noticed a subtle power loss on hills and more white smoke than usual (this car has burned very clean except at start up). I drove the car last week, and tested it on a few residential hills in the neighborhood. At idle, the engine revs well…on the flats power is OK, but definitely not as strong as a few weeks ago… going up steep hills is impossible.

Chassis Model Number

W123

Forums

Diesel Engine Specific Aid

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