quick rundown:

car is smoking very noticeably out of the tailpipe, its definately oil. #2 cyl sparkplug had oil on the fire ring only. there is zero oil going into the catchcan, no oil coming out of the valvecover breather and no coolant mix showing up under the oil cap.

compression on the engine (low miles ls stock bottom end) is 175 even and the leakdown is around 10%.

i can very well believe that an in tact ring but cracked ringland would consume some oil but not really loose compression because the ring itself is ok, but wouldnt it loose oil out of the catchcan/valve cover?

only other thing i can think of is hg between that cyl and an oil passage...

 

Not a ringland....your compression would be affected in that cylinder. You say your compression is even across the board but nothing is going into your catch can which would indicate significant blow-by so I'm leaning towards a worn valve seals/guide causing the oil to get into that cylinder. I'd pull your exhaust manifold off and see if your exhaust valves are wet with oil and or intake as well. Oil entering the combustion process will effectively lower the octane rating in that cyinder making it prone to pre-ignition and further damage.

 

#1. Your turbo feed. does it have a restrictor ?
#2. Remove DP and Check for Oil
#3. Remove Exhuast Manifold check for oil
#4. Get back to us...

 

well its not my car, i was posting for a friend.

turbo does have a restrictor.

i wouldnt be suprised if the turbo was bad, but then how would that get liquid oil back on the spark plug of just the #2 cylinder. there is no oil in the chargepipes for what its worth.

ill tell my friend to check the valves for liquid oil.

 

do a leak down test. NOT compression test.

 

we did. 10%. i said that in the first post.

going to tell the guy to check the valves for oil. weird it would be the valveseal though, the head was previously mine on one of my old cars and it never had an issue, it was redone 17k miles ago..

 

A simple bad spark plug oil seal in the valve cover can cause that to happen.

 

thought about the seal. i would imagine that there would be oil on the threads of the plug too though, and there was not..

the owner changed the plugs and reworked his oil lines, it still smoked so he took the head off. havent heard any further updates

 

took the head off, no oil anywhere in the cylinder. pistons looked good just some normal carbon buildup.

turbine housing and downpipe were full of oil, so one would think the turbo seal. replaced the turbo put the motor back together still smoking like a biotch. the tune is done and good.

 

valve seals could be going bad