webbywagon

Hi everyone and merry xmas (well almost). Newbie here with a problem with my wifes ML 270 CDI. It seems that when my wifes ML has warmed up and after driving for a while. When she is stationary, with the engine running and in gear with her foot on the brake, like being in traffic or at a junction etc.. Her ML starts to smoke quite heavily and the only way to stop it is to put it into neutral gear and when she does that the revs go up quickly and then settle at about 900-950 rpm. She has had a new EGR Valve. It is also sluggish to pull out of junctions etc...

harkgar

I am not aware of any ML 270 CDis imported into North America. Is it a grey import? What year?

Secondly, was it very humid at the time? What color is the smoke? Diesels tend to idle faster than gasoline engines and 900 rpm is OK. Does the vehicle have the 5 or 7 speed transmission? I do not know if any 7 speeds were installed into the ML 270 but late model gasoline North American MLs have the 7G transmission and are more responsive and economical on fuel.

240D 3.0T

There are no 270 ML's in NA. I'd bet the original poster is in Britain or Canada.

harkgar

240,

What do you have under the hood? I like the black smoke coming out under the car. Do you have straight pipes?

Cool. I wish I can get one like that.

240D 3.0T

I've got a turbocharged OM617 from a 300TD. No muffler(s).

harkgar

240:

Where did you get all the short shifters, water injection and the exhaust systems etc in such an old car? I am finding it difficult enough to find stuff for my 1986 MB. I am hoping to get someone to do the side pipes like yours. In the W126 it is easy to do, as there is a lot of room under the car in the middle.

Without no BS particulate filters, cats and other nonsense tree hugging devices in 1981 diesels you must be having a whale of a time blowing black smoke and making big noise. I really enjoyed your videos.

240D 3.0T

With pretty much a nonexistent aftermarket, I made it all myself or adapted it from another application.

harkgar

What about the noise level? Have you been stopped by donut eating fat guys driving Crown Victorias? I am tempted to do the same once the muffler goes. I have already cut off the 2 resonators and replaced them with 2 straight pipes.

240D 3.0T

I've been pulled over for speeding several times and once for a broken headlight. Never an issue with noise. I'm quite used to the sound level.

Stock MB diesels sound oddly quiet when I hear them drive by.

Mufflers can work in three ways. Absorption, restriction, and reflection. So in reality, a turbo is also technically a muffler because it's just a big restriction.

harkgar

240,

Does your car have a catalytic converter? I have been told by a good MB tech that the 2006 CDi has one. However, in Toronto the only emission test needed for 2006 and older diesel passenger car engines is VISUAL (no black smoke at idle). In other words if you have a friendly myopic tester you will pass and if someone accidentally remove the converter you will still pass.

The wonder of older diesel cars!

The

240D 3.0T

MB diesels sold before 1986 did not have catalytic converters (Except for cars sold in California in 1985).

harkgar

You are one of the best MB diesel techs here. Your recent comment really made me think of getting the 2006 instead of the Bluetec. Pity MB does not do something so powerful before the new rules come into being.

Blow black smoke and prosper!
Make noise, not war (unless on Communists)