I am new to diesel so would like some help/advise please. My vehicle is a
1993 Escort 1.8 Turbo Diesel. The car starts fine and will idle ok until the engine is warm, then the idle becomes rough, as though hunting on a petrol car. This produces black/grey smoke from the exhaust. The car runs fine, the turbo appears to come in ok, I assume this because you can feel an increase in power, and economy seems to be ok too. I have checked the air filter and this is clean. Am I right in assuming the smoke is being caused by incorrect air reaching the combustion chamber? Any ideas where to look. It may be unrelated but there appears to be, what I can only describe as a rattling noise from around the turbo area when this problem appears. Its not overly loud but is noticeable as it is not there when the engine is cold.
Any advice greatly appreciated