Hello, the engine was done with new pistons, new cap conrods, new valves, block honed to have a good crosshatch. The ring gap was checked and was ok

After doing miles to make sure that rings are fine, on the highway under heavy acceleration, sometimes!, we can see a lot of grey smoke and high oil consumption, the turbo was refurbished, the injector was tested. Car has downpipe. 

We have checked CCV/PCV membrane and was ok, no holes. There are bits that can cause this in rocker cover?

What can cause such high consumption under heavy loads? I'm lost!

 

Can injectors make such issues to "eat" oil?

 

Edited 16 February, 20242 yr by rares

@rares Given the recent rebuilt, my first thoughts are of a seized or broken piston ring, probably an oil control ring.

Which engine is fitted?

 

Sometimes after a rebuild after re bore/new pistons/honing etc it takes a while for things to run in / wear together and oil consumption can be on the high side for a while. But not usually with clouds of smoke.

 

Have new valve oil seals been fitted? Also check everything to do with Crankcase ventilation as if crankcase pressure is high oil can be blown past valve oil seals at times! If you get smoke when first accelerating after been cruising or on the overrun then I'd suspect valve oil seals or crankcase pressure. If smoke is more constant then I'd suggest a mis assembly issue re pistons / rings - might be worth using a bore scope to have a look to make sure those honed bores aren't being damaged.

 

I did something similar with an old Cortina 1300 many decades ago and had an issue with the replacement top rings as they came into contact with a slight wear lip at the top of the bore (I hadn't rebored) which damaged the rings. I partially solved by fitting a top stepper ring instead, although I ultimately regretted not getting a full rebore.