ML 270 CDi Black smoke on acceleration

[j911]

HI

This is my first post on here about my first diesel engine. Always been a petrol head prior to the rocketing fuel prices in UK. Anyways rant over.

So Whenever I accelerate whilst moving off or kick down i see a trail of thick black smog behind me with the ML seemingly lacking power and slow to accelerate at times. Kickdown seems non-existant in comparison to petrol engine. I don't see smoke from the exhaust below 2000 rpm or if i accelerate gently.

I tried the suggested route of unplugging the MAF and I do notice a difference as the smoke disappears and seems somewhat more responsive. I then swapped the MAF and unplugged battery as a member suggested to let the ecu reset (not sure if that is true) but same result. Could it be a clogged up egr or other issue?

I know this is a question asked quite commonly and most probably has been answered many times over but often lacking a solution. Hopefully we can make a sticky with all symptoms / solutions for EGR/MAF etc related issues.

 

[BlackC55]

It is quite likely with excess black smoke that one of the boost pipes has split or there is an EGR or MAF fault. Can you hear a whooshing noise under acceleration?

Get it on a Star first.

 

[j911]

Thanks for the prompt reply.

Yes I can hear a whooshing sound when accelerating roughly from the middle of the dashboard area, right?

I already replaced the MAF, and as I mentioned earlier unplugging the MAF causes the smoke to disappear. I was rather hoping that it would be helpful towards diagnosing.

I don't have any warning lights on. Problem is I don't know anyone in my locality North London in possession of a star. Would you say it's worth investing in one? Would MB carsoft be a somewhat cheaper alternative? As I have used it in the past for my BMW.

 

[john_ausm54]

I have simular problems

I blow black smoke but my smoke comes from the manufold area as well what could be the problem my ML270 cdi has done 207000k so I dont know where to start I would love to know or have a diagram where all the sensors are.

 

[dokalj]

where is the boost pipe? Where would I need to look?

 

[dokalj]

I have a whooshing sound upon acceleration.

 

[allias]

I have a whooshing sound upon acceleration.

Same here and have the same issue with smoke.

 

[mercyme]

Hi

Very interesting
I have Aclass 170 CDi with smoke problem(to point where other motorists make comments)no other symptoms at all.
Mot pass last month,took car to another branch of the chain,agreed lot of black smoke.
Diagnostic test showed only fault was egr.
Replaced it,no improvement.not happy,no sympathy from garage.
Wrote to Head office of chain,and they are arranging for one of their "master technicians" to look at car free of charge (in their words) to get "to bottom of problem",can't ask for more
Will let you know what they come up with.
Might be of some help.

 

[allias]

I forgot to mention as mine is fixed now. It was carboned up EFR as well as damaged MAF. Cleaned and replaced - Its all like new

 

[MarkF]

I forgot to mention as mine is fixed now. It was carboned up EFR as well as damaged MAF. Cleaned and replaced - Its all like new

What did you do to clean the EFR? where is this located as I have started to get a little smoke not much but I would like to check.

Many thanks

 

[ODUTEC]

Hello ..I am new to the forum..i have just bought a mercedes Ml270 and it's been nothing but trouble...Firstly the injector was leaking..BLACK DEATH...which is now fixed...but i now get black smoke from the exshaust when on idle and a lot more when i accelerate...i read in the forum about EGR and MAF to check..where are they located and is it something i can do myself...please help

 

[gtvlusso]

EGR clean is very easy. As you look at the vehicle front on, the EGR is on the right side connected to the front of the intake manifold. I have it cleaned as part of the yearly service.

You will need to remove the engine covers, remove the boost pipe and I think it is 3 bolts to remove the manifold - probably needs a clean out, check the inside of the manifold too. User on this site did a good write up with pics:

http://www.mbclub.co.uk/forums/engine/105515-ml-w163-270-egr-pipes-manifold-cleaning-2.html

The MAF is on the left side of the engine in front of the airbox (sort of connects into it). Again - 10 min job to replace - a new one is about £60. Common fault is high fuel consumption.

STAR will tell you if the MAF is knackered (the engine often goes into limp mode and won't go above 3000 rpm either).

As for black smoke and "whooshing" - either a broken boost pipe into EGR (about £12 and quick to diagnose/replace). Or, worst case, the intake manifold is cracked. If it is cracked, you will see oil on the underside of the manifold and running down the engine block. The intake manifold is plastic, but a bit of a nightmare to replace for a DIY'er. The part itself is around £300 from the dealer, but it will cost at least £250 to get it fitted - I would recommend getting it replaced by a Merc indie. Also worth replacing the swirl flap motor that sits under the manifold - if the manifold has cracked the swirl flap motor is sure to be full of oil - £90 part from memory - Basically, budget at least £600 for that lot!

Remember, the 270 engine is basically a van engine, just got an ML strapped to it - it is not that complex or fussy. None of the parts are excessively expensive and it is fairly easy to work on if you have some mechanical knowledge/experience.

 

[ODUTEC]

Hi J911...How did you stop your black smoke in the end..i have the same problem....

 

[ODUTEC]

Ml 270 black smoke

Thanks for the prompt reply.

Yes I can hear a whooshing sound when accelerating roughly from the middle of the dashboard area, right?

I already replaced the MAF, and as I mentioned earlier unplugging the MAF causes the smoke to disappear. I was rather hoping that it would be helpful towards diagnosing.

I don't have any warning lights on. Problem is I don't know anyone in my locality North London in possession of a star. Would you say it's worth investing in one? Would MB carsoft be a somewhat cheaper alternative? As I have used it in the past for my BMW.

How did you top the black smoke in the end....? I have the same problem

 

[Rob CCLASS320]

HI all,
After reading the above post, your all only combating a little part of the problem.
You need to ask at your local MB specialist that you want a BG Diesel air intake service.
This service will clean your EGR, intake manifold, valves, piston squish area, piston rings thus freeing them up and restoring compression. And what I like the most they put a fuel system cleaner in the tank that contains PEA technology.
The product does not burn it vaporises and carries the deposits out the exhaust.


This will stop any diesel from smoking.

 

[dokalj]

HI all,
After reading the above post, your all only combating a little part of the problem.
You need to ask at your local MB specialist that you want a BG Diesel air intake service.
This service will clean your EGR, intake manifold, valves, piston squish area, piston rings thus freeing them up and restoring compression. And what I like the most they put a fuel system cleaner in the tank that contains PEA technology.
The product does not burn it vaporises and carries the deposits out the exhaust.


This will stop any diesel from smoking.

Thanks, what is the likely cost?

Is this what they used on wheeler dealers on the Jaguar XK8?

 

[dav007]

hi allias did you mean egr vavle not efr

 

[andywilf]

No Power bad injector seating

Hi Rob, after recently purchasing an ML and I knew that it had black death from one of the injectors. I had an indy look at and change the injector which he also recommended getting all checked out. I took his advice and he suggested i replace one and get the others refurbed which i did. After several other minor issues I know longer have the car with the Indy and got it towed back. What a Nightmare but a story for another time. I have since taken out all of the injectors and cleaned up the injector housing and replaced all the washers bolts but not clamps. I have diesel leaking out of 3 of the 5 injectors. The car is awful to start and takes some time also it has little or no power, my question is as there is a leak on the 3 injectors is there that much significance in the loss of power? I shall be replacing the clamps when MB is open. I have also checked all the fuel lines and there is no sign of leaks/air bubbles. Im pulling my hair out as im beginning to wonder if what i thought was a bargain is turning into a nightmare.
All help would be very much appreciated.

Cheers Andy

 

[dokalj]

Hi Rob, after recently purchasing an ML and I knew that it had black death from one of the injectors. I had an indy look at and change the injector which he also recommended getting all checked out. I took his advice and he suggested i replace one and get the others refurbed which i did. After several other minor issues I know longer have the car with the Indy and got it towed back. What a Nightmare but a story for another time. I have since taken out all of the injectors and cleaned up the injector housing and replaced all the washers bolts but not clamps. I have diesel leaking out of 3 of the 5 injectors. The car is awful to start and takes some time also it has little or no power, my question is as there is a leak on the 3 injectors is there that much significance in the loss of power? I shall be replacing the clamps when MB is open. I have also checked all the fuel lines and there is no sign of leaks/air bubbles. Im pulling my hair out as im beginning to wonder if what i thought was a bargain is turning into a nightmare.
All help would be very much appreciated.

Cheers Andy

Hi Andy,

Sorry to hear about your problems.

Where are you based?

You need to find a good indie from the forum.

There are many good indies on here.

 

[LezT]

BG Diesel air intake service.

Hd it done, and have seen it in action on several other makes, the clean is better than anything I have ever seen in 30 yrs in the game, sometimes a badly clogged system may need doing twice for a proper clear out.
Lez.