Just doing up a sierra 2.0 dohc , was converted from a cvh 1.8 originally, cars up and running but smokey when drove hard or revved up hard , otherwise running well, seams like dark blueish smoke and at times nearly black, not sure if the air fuel ratio mite need to be set ? Or if its burning oil ? Any ideas thanks

 

Had one several years ago which did the same, ended up failing the m.o.t as they said it was burning too much oil. I suspect its the same and probably the valve stem seals

 

Do you remember Was yours smokey from start up and at idel , or just when under load

 

My memory not that good, but if I remember correctly it smoked all the time and was a common problem. It is not really a good engine so time to consider a zetec swap.