Recently my 2005 CRD started to belch black smoke and lose power. It only happens when the engine is hot. The black smoke is really thick, and comes out in clouds I can see in the rear view mirror. Like this when climbing hills, accelerating on highway from trailing throttle, or just overtaking. The idle is smooth, no strange noises, everything else sounds fine. The loss of power is annoying, as is the black smoke. If accelerating gently from standstill all the way up the redline,....no smoke, or not as much.
The Hi Scan at the dealer showing no fault codes for any of suspect components, ie injectors, fuel pump etc...... The air filter is clean, and I cannot find any restrictions on the air intake system. I am ruuning the engine on Caltex Delo 400, and the mileage is 14000km. Suggestions so far vary from wrong oil(?), poor quality fuel,... to EGR stuck open when the engine is hot. I thought black smoke normally result of incomplete combustion. When the engine is cold the car is running fine, no black smoke, when it's hot, like it's being choked. Any one got any ideas as to other poss. cause?