Damn Oil!!

[p_justin13]

So replaced old valve cover gaskets because they were leaking. Helped with oil consumption but..... I always replace pcv valve when changing oil and when replaced the manifold gasket common body was full of it! The tube from the pcv to the intake was caked as well. Cleaned out the tubing and the manifold and put in another new pcv valve. Ran for two weeks and tube and intake were once again caked with oil. Is there anything else that could be causing raised crankcase pressure causing massive amount of oil to be pushed up into intake? Any thoughts??

[IndianaVX]

Is it oil only, or isthere any coolant mixed with it?

[atilla_the_fun]

You could consider replacing the PCV valve with a breather, eliminating the flow of oil into the intake. We don't know if oil comes out of the breather, however. Search this site for a more in depth look at pcv replacments, breathers, and catch cans (which you can use to fiter the oil before it reaches the intake.

[PK]

With your engine idling, slowly remove your oil filler cap to check if there is excessive piston blowby.
If oil is being thrown out = bad news.
If it appears ok, just hold your hand over the hole for 30 seconds.
If your hand is oily, you have some blowby, but probably not excessive.
If the pressure pushes you hand off - run.

PK

[p_justin13]

Topped off oil started up and pulled oil cap placed piece of paper over and pushed down with my hand. Not even so much as a drop of oil. Any other ideas???

[Scott Larson]

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.

[Y33TREKker]

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.

[PK]

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.

Scott, you are correct. A sticking ring might need a higher load than idle for it to play up. Possibly even more load than just revving the engine while stationary, so it is hard to test that one.
The Sea Foam treatment could work.

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.

Trekky, IIRC there are 3 rings on our pistons.
The top ring seals compression in the cylinders.
The bottom ring controls oil on the cylinder walls.
The middle ring is multipurpose - it does a bit of each.

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

PK

[Ldub]

Trekky, IIRC there are 3 rings on our pistons.
The top ring seals compression in the cylinders.
The bottom ring controls oil on the cylinder walls.
The middle ring is multipurpose - it does a bit of each.

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

PK

X a factor of 2...

I've gutted my PCV system, & it now flows freely into a catch can, which is vented into the air box, with zero reduction in oil consumption.

[Y33TREKker]

Scott, you are correct. A sticking ring might need a higher load than idle for it to play up. Possibly even more load than just revving the engine while stationary, so it is hard to test that one.
The Sea Foam treatment could work.



Trekky, IIRC there are 3 rings on our pistons.
The top ring seals compression in the cylinders.
The bottom ring controls oil on the cylinder walls.
The middle ring is multipurpose - it does a bit of each.

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

PK

Trekky?

Anyway...

I was just going by your original post, and not the additional things you've now brought up. If you guys want to have yet another discussion regarding the various trains of thought regarding oil consumption in VX's, have at it.

But as I said, even if there is blowby, it still has to go through the PCV system for oil to get to the intake, which is what we're trying to figure out for p_justin.

[p_justin13]

Running sea foam through crankcase now will do upper intake tomorrow with oil change should have a hundred miles by then with sea foam to run through thuroghly through the engine. L dub how did you Jerry rig up you catch can setup any pics. Will probably do this anyways afterwards. Also is there any chance that a plugged up muffler raising the back pressure could effect this situation??

[Ldub]

L dub how did you Jerry rig up you catch can setup any pics. Will probably do this anyways afterwards.

As requested: http://www.vehicross.info/forums/sho...t=breathe+suzy

[Scott Larson]

Trekky?

Anyway...

I was just going by your original post, and not the additional things you've now brought up. If you guys want to have yet another discussion regarding the various trains of thought regarding oil consumption in VX's, have at it.

But as I said, even if there is blowby, it still has to go through the PCV system for oil to get to the intake, which is what we're trying to figure out for p_justin.

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!

[Y33TREKker]

Positive Crankcase Ventilation is exactly that...

When it's working properly of course. Given all the related problems seen to date on this board though, it's still debatable whether the design of the PCV system on VX's actually works the way a PCV system is supposed to work.

[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.....