Black smoke on acceleration

[richard@focal.co.uk]

Hi
I own a 2001 S320CDI and have recently noticed black smoke from the exhaust on heavy acceleration. It does not happen when accelerating slowly or when the engine is in neutral or park.

Does anyone have any ideas on this. I know some Diesel engines are prone to smoke on acceleration, but this has not always happened.

Thanks and regards
Richard Knight

 

[BlackC55]

I would be looking at the EGR valve. It can be cleaned but a new one is generally better. They are about £270 fom MB

Easy to fit yourself. Its located on the inlet manifold.

 

[hmang]

if the mileage is getting on a bit (100ish) and the car is otherwise well serviced.
i'd look towards the injectors....sorry...i know you didn't want to hear that .

my 220 cdi did exactly the same black smoke thing and got so bad at 150k that there was a sooty deposit up the fear fender after a good run.
replaced the injectors and seals ...ouch ...£500 ...sorted.

you may not get the sooty deposit on the s class because of a different exhaust exit..mine shows no sign on the bumper but it is quite smokey....i noticed it by following the missus...believe me it's doing it on gentle acceleration too but you can't see it from inside. the s class has 110k so it's time to bite the bullet on that one too, especially as i have at least one leaking injector allowing air into the system...

maybe we should get together and try get bulk discount

 

[Dosco]

maybe we should get together and try get bulk discount

:idea: Now theres a thought, would it be possible for other stuff as well? such as brake pads, discs, filters and other accoutrement's as well the odds and sods.

Any idea how hard would it be to set up with a really friendly supplier a decent set of terms for members to purchase their 'requisites' and or 'something for the weekend sir' stuff

 

[Parrot of Doom]

Well first I would give it a good Italian tuneup. Diesels often emit sooty clouds if you've been driving like a granny for a few tens of miles.

 

[hmang]

Well first I would give it a good Italian tuneup. Diesels often emit sooty clouds if you've been driving like a granny for a few tens of miles.

watch out for them cameras

 

[Maxbumpo]

Well first I would give it a good Italian tuneup. Diesels often emit sooty clouds if you've been driving like a granny for a few tens of miles.

Bingo. Here in the US of A we have a couple of products that work wonders: Chevron Techron concentrate fuel cleaner and Lubro Moly Diesel Purge. They can speed up the cleaning process, as can use of Mobil 1 synthetic oils. Best long term fix is to use good clean diesel fuel and drive the car hard (wide open throttle at every opportunity).

 

[hmang]

i'm very interested to see what works for you here .
please post your results.