black smoke from exhaust

Mar 24, 2008 4 Replies

My diesel R reg Astra blows black smoke when I rev it. When driving I don't see smoke nor when idling. I have to get it through the MOT test soon. Other than changing oil and oil, air, fuel filters and putting injector cleaner in the fuel is there anything else I can do?


It appears an Italian tune up is required. Sounds like excessive carbon build up. Common on diesels that are driven gently. Put it in 4th or 3rd and floor it on the motorway for 10 - 15 mins. Make sure it's well serviced and timing belt is ok. A shot of redex may also help.

Doing the above carefully defeats the point. You need to find the governor a few times under load.

I would recommend using second gear. Put your foot hard down (on an empty road) and keep it there until the smoke clears behind you. Higher gears don't work so well.

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