BMW Repair: Engine condition, leak down test, oil consumption

Question
Evan,

I have a 2000 528i which has done 144000 km. When I put in 15w/40 oil it consumes almost a litre for 2000km. There is no black smoke, I have done a compression test & it comes up fine, there are no leaks. Is there any other way of diagnosing if there is something wrong with the pistons & rings or any other engine condition which might be causing this oil consumption?

Thanks,

Janak.

Answer
Janak, what are your dry compression numbers? With a battery charger of significant size run a second compression test 'wet' Squirt a little oil in the cylinders and see if the numbers jump up 30% or higher. You should also be using 5W-30 full synthetic oil not 15w-40. You can also perform a cylinder leak down test to see where the most air is leaking from. Oil cap or dipstick tube is worn rings. Smoke would be blue for oil not black.
-Evan