ML 270 CDi Smoking

[Duncan.ml]

Hi There,

I have recently purchased an ML 270 CDi (X reg - 2000) but I have noticed that it is smoking lightly (black smoke) when driving normally and lets out a big plume when I nail it! It's not burning any oil but it horrendous on fuel. I've had it checked for fault codes and there are none. I've been told it's an overfuelling problem. Does anyone have any clues on a cure??

 

[type49]

Try a search on here on how to clean your MAF/MAS meter. These give many problems so a clean is the first thing to try.

 

[panason1c]

First basic check is the condition of the air filter.

 

[television]

As above change the filter

 

[Duncan.ml]

I have now changed the airfilter, fuel filter, air maf/mas sensor (all with genuine merc parts) given it a good blast up the motorway and it's still smoking!
Does anyone have any ideas where the problem could lye??

 

[panason1c]

I have now changed the airfilter, fuel filter, air maf/mas sensor (all with genuine merc parts) given it a good blast up the motorway and it's still smoking!
Does anyone have any ideas where the problem could lye??

Hi,
Does the engine run smoothly and with no apparent loss of power?

Could now be an injector problem, an injector leak off test would be my next move and then a cylinder compressions test if the leak off test checked out ok.

Also, before any of the above, check that the EGR valve is not faulty (stuck open).

 

[Duncan.ml]

Looks like I may have cured the problem!!!

After trying many things with no cure, I was given the number of a clever diesel bloke!

I explained to him the problem, told him that I had changed the air filter, fuel filter, Air Maf sensor and it was still smoking! I was concerned about having to fit new injectors as this would be costly and I only wanted to do it if it
would cure the problem.

Straight away he said it definatly won't be the injectors! What happens is that at some point in it's life it has probably had a leaky injector and it has been taken out cleaned, put back in with 2 copper washers for a seal. I took out the first injector and bingo! 2 copper washers! Phoned up my local Merc dealer ordered a copper washer (49p!!!) job done! No smoke, no leak, EXCELLENT (although you do have to make sure the seating areas are immaculately clean or it will need re-seating)

So hopefully my fuel consumption will now improve too.

Many thanks for anyone who gave me input and ideas to fix the problem and I hope this will be helpful for someone else!

Kindest Regards

Duncan.ML