Hi guys, first post here, 

 

I have a fiesta st150 2006  that seems to be using a fair amount of oil. 

after 4k RPM with load you can start to see a blue mist of burnt oil out the rear view mirror. on idle, low rpm nothing. 

sometime it dose not smoke even into the high rpm range? 

One garage has told me it bore wear, ££££ another has told me valve stem seals again ££££

the car dose not smoke in the morning, it does not smoke when lifting the pedal. the car seems to run pretty well, with plenty of power still non of the 'typical' stem seal issues

All 4 spark plugs are black! coated with oil again normally i expect one cylinder to be bad but not all 4?

 

any help would be greatly appreciated. 

most likely is piston rings. normally its the 1.8 duratec we hear of , but its basically the same engine as 2.0 . 

i dont think its the rings as there is no set pattern as to when it decides to burn oil

50 minutes ago, danieljw said:

i dont think its the rings as there is no set pattern as to when it decides to burn oil

You could say the same thing if it was bore wear or valve seals. Being an ST it's probably had it's fair share of boy racers behind the wheel who red line it 30 seconds after starting the engine. Wouldn't surprise me if the rings are gone.

Just out of interest have you checked to see if the PCV is ok? If it's failed then that has the potential to build up pressure in the crankcase and push oil past the seals.

Did you solve it ?