Hello, this is my first post here and I'm hoping that I can get some help. Over winter I inherited my grandfathers 1977 300D. It only has 116K on it, it was garage kept all it's life since he bought it new and he took great care of it. It had sat in an air conditioned garage for the last 10 years or so, only being driven maybe once or twice a month. I just got it looked over at the local Mercedes garage and was told everything is good other than a gasket to fix a very minor oil leak. But on the way home my g/f was following me and said the car was pouring black smoke. I have been trying to drive the car a good bit since I got it hoping that it would 'clean out' what ever was causing the smoking, but it's still doing it. Any suggestions on how to fix this? It's kinda embarrassing having a good looking car that poors a black trail behind it.

 

Black smoke means too much fuel or fuel at he wrong time . The simplest thing to start with is the injectors, they could be leaking, pull them and have them pop tested calibrated and new nozzles installed. Many diesel vehicles emit a bit of black smoke when accelerating hard but black smoke all the time is a sign of injection system issues. Search the forum for other members experiences with similar issues. Cheers Dan

 

I forgot to mention. Get some "Diesel Purge" made by Lubro Moly available from retailers and online Mercedes parts suppliers & run that through the injection system from a small container. It is a very strong solvent which will clean a lot of the crap from the injection pump and injectors. It only takes a half an hour or so and will help anywhere from a little to a lot. Costs less than $10 a bottle , get two for good measure. Cheers Dan