Exhaust/smoke Problem...

[jhatter]

I drive a diesel C5, registration is 2002, manual, HDi 110.

 

Driving down the motorway recently it was as though the car 'coughed'.  Without any loss of power it gave a small shudder and a cloud of black smoke shot out of the back, I'm assuming from the exhaust.  I continued my journey home. 

 

The car sat outside the house for a week, next time I started it gave out another black could of smoke.  Although the clouds of smoke have now ceased and there appears to be no issues with the engine or the power, there is a distinct 'burning' smell from the back of the car that is noticed when shutting off the engine after use and getting out of the car.

 

Any suggestions as to what this may be.  Is this a simple case of a filter needing replacing or cleaning?

[paul.h]

A few ideas to consider -

 

- something stuck to the exhaust like a plastic bag or maybe an oil leak on to it

- a leaking fuel injector cylinder head seal - if you lift the bonnet you may hear a chuffing noise or see carbon around an injector

- a leaking pipe around the engine

- egr valve problem - check its pipe connection if vacuum operated

- a problem with the turbo - how many miles has it done ?

- how many miles since the air and diesel filters were changed ?