W210 E300D 96 feels like its missing badly on inclines,

[johngreen11]

My 96 W210 E300D seems ok at idle and when driving on the flat but feels like its missing going up hill. Engine surges, loses power and puts out lots of black smoke. Occasional knock can be heard when this happens.

It feels just like a plug has gone on a petrol engine.

Any ideas where I should start looking first.

The fault suddenly appeared

regards John

 

[190]

I would first check the air filter, then fit a new fuel filter sounds like it,s not getting enough air intake hence the black smoke, the knock most likely is a diesel knock getting to much diesel while under strain.

 

[landover]

Check there is no oil lying in air filter housing. It might be drawing old engine oil in threw the intake.Remove air filter and check . :wink:

 

[bigt]

black smoke

Usually black smoke from a diesel indicates one of 3 things:

1. Lack of combustion air
2. Injection fault
3. Overloading of the engine

The fact that the engine surges may suggest an injector / injectors not atomising properly. What is your mileage and when were the injectors last overhauled.

 

[johngreen11]

Thanks for all your replies.

I've changed the air filter and the oil filter.

The diesel fuel filter is also new.

No oil in air filter area.

Running on full synthetic 5/40w oil.

Mileage 158,000. Owned the car since 48,000 and no injectors have been replaced in that time.

Do bad injectors cause a sudden problem like this. The car was ok on a run and then suddenly gave the problem on a hill. Problem is always present now.

regards John

 

[bigt]

injectors

Hi John,

You have done well to get 100k+ out of the injectors and yes they can cause those symptoms, as the engine comes under more load with faulty injectors or injection pump you get knocking and black smoke from incomplete combustion because the fuel is not atomising properly.

It is a good starting point to look at.

 

[dieselman]

Probably the fuel lines leading to and from the filter are leaking air. This then causes the pump to suck air under load, which then retards the injection timing so produces smoke and finally the coughing and knocking when the pump sucks air.

Run a good dose of injector cleaner as well, but I would be surprised if the injectors are worn, unless you've been running the car on parrafin.

 

[johngreen11]

Had injectors checked by specialist and they are perfect.

I suspect air leak in system as I have replaced black return pipe with clear pipe and can now see lots of bubbles at 2-3000 rpm.

Looking for leak this week end.

John