Sr20 Blown piston rings or Valve Steam Seals

[nsfmike240]

I have s13 sr20det blacktop , it is blowing blue smoke , It only happens under boost while driving, i pushing 11psi, the engine is stock , I compression tested it and cylinder 1 was 149, cylinder 2 was 135 , cylinder 3 was 135 and cylinder 4 was 40 , Then i wet test cylinder # 4 and it only went up to about 42, I was told if i wet tested it and it went to like 135 then it would be my rings, but if only went up a little bit it would be either my valve steam seals or valves,

[ultimateirving]

ever consider turbo is also leaking.. check your intercooler for pooling oil at least to rule that out

[4x4le]

the turbo wont cause low compression numbers. Do a leak down test and see where the air goes. If it comes out of your intake or exhaust its valves. If it comes from your crank case its your rings. Valve stems wont cause low compression numbers either.

Either way, your engine is going to be coming out, or at least the head is coming off.

[s14unimog]

^Brandon, either way, its going to show air flow out of the V/C. You'll have to remove the V/C to differentiate if its valve seals or rings. But considering you tried improving the ring seal with oil and nothing changed, it's likely the rings. What's weird though is that when rings go you get a lot of blow by, so air is forced out your crank vent and into your turbo,piping, manifold etc... I shattered the rings on my #1 and it would just show oil deposits in the catch tank; never blew smoke. Maybe the smoke is coming from oil collecting in the charge system or through the PCV.

Brandon's right though, it's gotta come out anyways with compression numbers like that.

[nsfmike240]

im going to leak down test it today but, if i did a wet test it was the around the same wouldn't i rule out the piston rings because the oil should create a a seal around the piston ring that would bring my compression up like to another 100psi. So i know my piston rings are good. Ill let u guys know what happens today with the car , If you guy have any suggestions just let me know. Thanks