burns oil.. sometimes?

[khartley]

My car has been burning oil for a while now, and I'm basically just trying to keep it going until I can get all the parts together for my build.

I have 120 compression all the way across. After idling a bit, sometimes a massive cloud of oil will come out. Sometimes just a little smoke. Sometimes none at all. Sometimes it smokes while I'm idling. Other times it doesn't. I never see or smell it when I'm just driving or under boost.

Anyone have ideas of what could cause the 'occasional' burning of oil?

 

[DSM1G90]

After idling a bit, sometimes a massive cloud of oil will come out. Sometimes just a little smoke. Sometimes none at all. Sometimes it smokes while I'm idling. Other times it doesn't. I never see or smell it when I'm just driving or under boost

Valve seals are gone for starters...oil seeps past the valve stems and pour into the chamber. Why you don't see it while driving is with the very little oil that is actually seeping past the seals will not be noticable out of the pipe, but on idle where there is no load on the motor, motor is turning slow and very little fuel is needed, the oil seepage doesn't get burnt off and will actually pool on the top of the piston itself. Then when you add fuel to take off, all that oil will suddenly get burnt off .. why you contribute to the pollution factor when the light goes green.

I bet when you do the 'finger wipe' in the exhaust pipe, it comes out very slimey and gooey black instead of a dry carbon soot black. Definite signs for a rebuild of your motor.

-DSM

 

[toofast82]

Well said above!
Do a compression test again and add oil, if the numbers don't go up, your seals are definitely shot.

 

[khartley]

I kind of had the same idea, but I thought could be the turbo, or oil rings so I thought I'd ask a second opinion. Weird thing to happen to an engine with very little rough treatment and only 111k miles on it. Thanks guys.

 

[DSM1G90]

111k miles on it

...and usually around this mileage on all motors is when seals are showing that they are getting dried up...and this can also show up on crank and cam seals being that these seals are made of the same compound as for the valve seals..

 

[khartley]

But you know whats weird, I drove the thing yesterday, and hardly no smoke at all. I idled for a minute or so a couple times, and just a tiny bit. I don't understand how it fluctuates so much.

 

[splatter96]

if it happens when you go up hills or when you at a stop and then start to move im betn on valve seals i had the same problem and my valve stem seals on my exhaust side was all worn ### my valves all had play in them on the exhaust side.

 

[DSM1G90]

I don't understand how it fluctuates so much.

B-cause the valve seal material (being a teflon plastic material)l is doing the flexing (if it can...) - being so worn out. Sometimes they will seal okey, and other times it just doesn't want to seal.