Just got everything else sorted out with my new (used low-mileage) engine, got it idling, no leaks, etc. Once it was warmed up I stabbed the throttle and hit barely 4k before lots of blue oil smoke came from the exhaust. It was puffing a little at idle, but it was below 0 degrees C here so I didn't think much of it.

After that I tried adding a lot more gasoline (to dilute any premix in the tank) and then started the car and held it above 4k, same problem without improvement. I held it at 6k for about 20 seconds as well, and even more blue smoke came out. As far as I can tell these are classic oil-control o-ring symptoms.

I still have the oil metering pump, but I can't think of how it would cause this quantity of oil to be sucked into the engine.

When I bought a used 30 year old supposedly original engine, something internal being bad was a known quantity (factored it into the price I paid). I just wanted to see if anyone else has suggestions before I starting removing the engine for a rebuild.

Thanks, Chris

 

Is it possible that you may have put the oil seal springs on backwards causing them to coil inwards under load? I know, it's not what you want to hear.

 

Also, did you delete the PCV valve? If so I would put it back in and see if your problem disappears. You may be spewing oil into the turbo.

 

I actually just bought this engine as a shortblock, supposedly original 80k km. Previous owner said it was running fine and pulled it to do a turbo swap, but I'm not sure if he actually drove it enough with this engine to even notice a problem.

I did notice the front and rear rotor housings have been marked, so maybe it has been rebuilt before.

I currently have the nipple on the oil filler neck going into a catch can with the nipple on the intake capped. I planned on recirculating it once everything else was sorted out. No turbo, 86 NA with 87ish engine (later style coolant sensor).

I can reconnect the PCV valve as stock though, it's worth a try.

 

Keep us posted!

 

How much premix were you running in the tank? If it still has a functioning OMP system, you don't need to run all that much (or any) premix - 1st thing to try is to not run any premix, and see if that changes the result.

Since you don't have a turbo, if the smoke show continues it's either a buggered up PCV system or insufficient oil catch can/vent setup (i.e., too much blow by pressure), or worn out oil control rings. Quick test to rule out PCV or catch can is to rev the car in neutral with the oil filler cap removed - if the smoke show goes away completely or is substantially reduced when you rev it past 4K, it's a PCV/crankcase ventilation issue.

 

I was running some premix because I replaced the OMP lines when I installed the shortblock and they take awhile to fill up. I thought I had done 1oz/gallon for the new engine but it's very possible that I made an error, since it's been awhile since I mixed it.

The plan for tomorrow is to try it with the oil cap off and see what happens. If the smoke doesn't clear I'll go out and get even more gasoline to try diluting the premix.

I'll report back with my findings.

 

Success! Leaving the oil cap off cleared it up. Zero smoke, even at sustained high revs.

I did have the oil filler vented and the center iron nipple going to the charcoal canister as stock. Maybe my charcoal canister is blocked internally? Going to a catch can for now until I figure it out.

Thanks to everyone for the help