Damn Oil!!

[VX KAT]

Yes, a stickey ring. At idle the ring conforms just fine to the cylinder walls. At higher rpm the ring cannot move in the lands fast enough to seal against compression, resulting in blowby, hence your mess...You could try a flushing agent such as Sea Foam in your crankcase and hope for the best, otherwise a rebuild may be in your future. Sorry.

So, it is possible to have excessive blowby without being an oil burner, and vice-versa.

PK

If it's blowby though, isn't the only way that oil could get back up into the intake is if it went through the PCV system? No excess pressure at the oil filler cap would seem to indicate that it's not blowby, although if it was only checked at idle the higher rpm condition described wouldn't have been addressed.

For whatever reason, the PCV systems on individual VX's seem to just be hit or miss as to whether they function correctly. A simple breather filter to replace the PCV valve eliminates even the chance of what's being described as happening though.

If a VX suffers from oil usage because of a problem with the piston rings, oil usage is going to occur anyway, regardless of whether a PCV system is even in place.

Further discussion? Don't mind if I do, thanks!

Positive Crankcase Ventilation is exactly that, it allows for the ever-changing volume of air in the crankcase to be expelled and subequently replaced as the volume changes due to the reciprocating pistons in their bores. If you introduce an oil mist into that atmosphere, either due to oil being blown by the pistons rings or too much oil in the sump being contacted by the crank journals, that oil will find it's way out of the pcv system along with the air. A small amount of oil mist is normal, it is when it becomes excessive that you have the problem described...ultimately, it is the function of the pcv valve to regulate or control the volume of air entering or leaving the crankcase, not to separate oil from that air. Provided all internal baffles are in place to impede the flow of normal oil mist, a catch can is not required.

Hope that helps!

Just curious how this all works.....So when you say "blowby", does that mean the oil or oil mist actually gets PAST the piston ring when it's going up/down, but not fast enough, and is pushed up and out of the cylinder through the PCV?
Why wouldn't that oil/mist combust within the cylinder and result in white smoke?


PK, explain this again.....
"So, it is possible to have excessive blowby without being an oil burner, and vice-versa."


Overall, I'm still amazed at how important that dang $3 part is.....