My 1992 400e which I have owned since (1997) 79,000 miles and now has 243,000 miles is finally having some of the traditional problems associated with this model.

Car gets oil changed ever 3,000 miles, ATF 30,000 miles. Car is immaculate by my standards. I am a light DIY, Stuff like the hood insulation, brakes jobs, cooling fan housings, door locks, washer fluid assembly, shocks & struts, belt & tensioner replacement, etc.

I also did the plug wires about 40,000 mile back.

Car was running Ok when I decided to have my indy replace the cam chain & tensioner (loud at start up) for the first time (242,000 miles), Well of course when removing the valve covers the air hoses broke and the wiring harness cracked, all original. Now the car after spending about $3,300 has a new intermitting problem. Occasionally after car warms up hot it feels like the car drops a cylinder and idles very rough, then for no reason (sometimes an hour later) the car will runs good. Also there is a slight hesitation now when starting out from low idles. Above 1000 RPM the car is running fine all the time. Gas milage has dropped 1 - 1.5 miles, down to 19 miles per gallon.( This may be my transmission though. I am thinking it may be the air mass meter (original), but why now after all the other work has been done. Has my indy done something to cause the problem? Could my new wiring harness be defective with a broken internal wire with loose connection? We took the codes off the computer and had many since it hasn’t been cleared in years. I am waiting to check again tomorrow.

I have considered Fueling pressure, throdle positioning sensor, Broken plug wire, I have had transmission fairing problems and replaced the kick down cable. Could the Transmission in any way cause the idle to be rough?

I would appreciate any Ideas.

I love my car, I guess I am a fool to keep it so long!

M119's are hard on distributor caps and rotors.

When was the last time yours were replaced?

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Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

I replace the rotors & distributer caps at about 200,000 mile, 43000 miles back

tkplay

have you ever been to the 500Ecstasy website?

it seems rough idle is somewhat common, sadly.

http://www.500ecstasy.com/forums/forumdisplay.php?s=&f=6&page=1&pp=25&sort=lastpost&order=desc&daysprune=-1

i'm chasing leaking valve cover gaskets now myself.

had you ever done anything with your leaky headgaskets, before the timing chain procedure.

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*92 400e 124.034, SOLD

*92 300e 124.030, SOLD

43,000 miles is long enough .... Time to change the caps and rotors.

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It is a truism that almost any sect, cult, or religion will legislate its creed into law if it acquires the political power to do so. Robert A. Heinlein


09 Jetta TDI
1985 300D

ebenz,

I have looked over at the http://www.500ecstasy.com/forums/for...c&daysprune=-1

Your are correct there is lots of good info there. I realize I could have a complex problem that surfaced because I fixed many air lines and vacuum lines and now the computer is relearning the cars readings. I also realize that the mechanic who worked on my care may have damaged something simple, like the plug wires. I am just trying to consider everything possible. These forums are a fantastic place to learn the true nuances of your Benz. So much experience here. I welcome all opinions.

I am going to change to plugs and caps and roters first. WILL KEEP POSTED.

My 400 E is just like your white 300E in your garage, but I have yellow marker lights. I even have the Mercedes 140k kilometer medallion on my grille.

As for the head gasket I have not had that leak, but valve covers have, I just let them leak. I was lucky to go 243000 miles before I ever took them off the first time. The leak was small on the right side, It started around 180,000 miles. Left side never leaked. Replace valve cover gaskets was done by my Indy, but should be easy if you can get them off without braking old air lines and such. As mentioned before mine was done when I did my chain. How many miles do you think this car can go if maintained properly? My engine is very Quiet and smooth when it is idleing normally.

I could buy a newer one, but I love my cars performance and handling. I have never had a car that I did not eventually tire of until this one.

It seems to me like the W124s are the last of the classic MBZs.

I have a similar problem. My car idles very smooth until it reaches operating temperature (which takes a while because I have a bad thermostat). Once I hit 80° C it starts to shake a little at idle and pulse. It sounds to me like it is missing spark. All of my plug wires and harness are brand new I can tell and I just changed my plugs. However, I removed my distributor caps the other day and they look pretty bad.

I also wonder if I have cooling problems such as aux fans...I guess I wont really know until it warms up a bit.

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• 1993 Mercedes-Benz 400E *146,000 Miles*
• 1985 Mercedes-Benz 300SD Turbo Diesel Biodiesel *SOLD @ 346,000 Miles*
• 1984 Mercedes-Benz 300D Turbo Diesel Biodiesel *SOLD @ 284,000 Miles*

You seem quick to blame the tech....

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RIP: 80 300SD
RIP: 79 450SEL
2002 E430 4matic (212,000km)
2002 ML500 'sport'

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FACEBOOK: PANZER450

I had a similar but not exactly, type of problem . It only happened after engine was warm and I found one of the coils arcing at around 1400-1800 RPM.

Worth a look. Everyone said change harness but coils it was and harness may be good for another 4-5 years 1993 400SEL which my mechanic said has the same engine as the E .

Before coils, I tried caps/rotors, plugs,plug resistors( 3 of them ) and fuel filter


My car threw absolutely no codes
Good Luck

I just had similar issue on my 300E and it was an arcing plug wire (I could hear a "tic-tic" sound that wasn't there before with hood up). It was hesitating and not starting very well. Could be coil issues, wires, distributor, cap...something along that area.

I should also add that I do have an engine code. The shop that read the code for me said it was something about the Air Pump for emissions and a communication error between 2 modules...

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• 1993 Mercedes-Benz 400E *146,000 Miles*
• 1985 Mercedes-Benz 300SD Turbo Diesel Biodiesel *SOLD @ 346,000 Miles*
• 1984 Mercedes-Benz 300D Turbo Diesel Biodiesel *SOLD @ 284,000 Miles*

1992 400e follow up
423000k
Rough idle - replace capacitors in Ecu (LH modual)