I borrowed my father in laws car today and its doing some odd things
The car is a 04 307 1.4 HDI
When the car is cold and you put it under load at low RPM it will make a quite loud pinking type noise and have a loss of power, Then the noise will stop, as soon as the noise stops the power returns and it will puff out White/grey smoke. it will then drive ok until you have to put it under load at low RPM again
it only seems to do it when cold

My 1st thoughts where the turbo compressor wheel could be getting stuck but i dont think the turbo would make the pinking sound

Any ideas?

anyone?

Could be leaking injector seals - are there tar like deposits around the injectors?