Citroen C8 - Citroen C8 Black Smoke intermittent - markyf

Hi All,

I have a Citroen C8 SX hdi 2.0ltr with an intermittent problem.

I drove it from England to the South of France and within 100 miles of motorway driving the car started to slightly judder and if i took my foot from the accelerator and pushed back down then it wasn't very responsive and slow to react, i could also see smoke from the back. After 5 miles it was fine.

After another 450 miles it did exactly the same. this time i pulled into the services, rested for an hour and set off again and the problem was still there, but disappeared after 5 miles again. It was smoking and smelling odd, but it drives fine. the anti pollution light wasn't on and there were no warnings.

I had the car serviced, oil and filters changed before this trip and i have just had the cambelt, water pump and MAF sensor replaced, but this problem was there before.

Any help would be greatly appreciated,

Thanks

Mark

Citroen C8 - Citroen C8 Black Smoke intermittent - Peter.N.

Black smoke is an indication of incomplete combustion due either to lack of air or overfueling, if it was the latter you would also get an increase in power so the chances are it air starvation. Have a good look at the air intake pipes, its possible for one to collapse under vacuum, if it had a new air filter have a look and make sure it doesnt have a loose lable.

Citroen C8 - Citroen C8 Black Smoke intermittent - markyf

Thanks for your advice, i will check it out.

The problem is only intermittent, would this fit with the prognosis you gave?

Thanks

Mark

Citroen C8 - Citroen C8 Black Smoke intermittent - Peter.N.

If its a collapsing hose it could be, it may only be when there is a large flow of air that it happens i.e. at full throttle under heavy load.