my escort cossy seems to have started smoking on long over runs down hill i have had the turbo rebuilt as i was told this could have been the cause but it still blows a puff of smoke. i have also had a leak down test done and was told that the engine was fine. could anyone tell me if valve seals would cause this or is it piston rings, any suggestions welcome.

 

Yes could be valve seals.

 

stem seals

 

thanks for your comments, but if it was valve stem seals are worn wouldnt the car smoke on start up as mine doesnt also is it right that if the seals have gone then the guides would probably need doing as well ?