1987 Turbo Burning Oil at Idle
 

Hello,
I've been having an issue where whenever I let my car idle after about 30 seconds it starts billowing out oil smoke. The second I start driving it it clears up right away. I originally thought it was the turbo and swapped it out, but that only worked for about 70 miles before it started doing the same thing over again. I then got the turbo professionally rebuilt, and it lasted about 40 more miles before doing the same thing again. At this point I'm at a loss as to what might be causing this issue. The car runs perfectly fine, there is no oil in the intercooler anymore, and I pulled off the oil cap and that didn't seem to change anything at all.

The turbo has a fair amount of oil on it, dripping on the turbine housing. It also smokes a bit from the passenger side of the engine compartment (which lingers for a bit even after the car is off), but the majority of the smoke is coming from the exhaust.

Thanks,
Zeke

I would consider worn oil control rings at this point.

I was thinking that as well, but the fact that it is only at idle gave me a bit of pause. I was under the impression that oil control rings tended to smoke at higher RPMs, where my car only smokes at idle and driving it cleans up the oil burning immediately (even revving it to redline creates no cloud of oil smoke until 30 seconds after it drops to idle). I could be wrong on that tho.

Where exactly is the oil smoke coming from when idling - out the tailpipes, the area around the turbo, or both places? If the answer is just the turbo area, and since you said there's oil dripping on the turbine housing, you probably have a leaky connection at the turbo oil supply line, and that oil spilling onto the hot turbine housing is the source of your smoke. You see it at idle because the car isn't moving - when you drive off, airflow tends to dissipate the smoke show, so you may not even notice it but it's still there.

Both .

Then part of your problem is the oil feed leak, need to deal with that anyway - fix the leak, clean any mess, and the smoking near the turbo should go away.

Don't think oil control rings are your problem - that usually shows up as excessive oil smoke on cold starts that persists for quite long time after startup, excessive oil smoke during deceleration / high RPM engine braking conditions, or prolonged high RPMs in neutral/no load.

Since you said the IC & IC piping is clear of oil, and if it's not an oil control rings issue, the only other place tailpipe oil smoke could be coming from is the turbine oil seal. What kind of turbo is it, and who rebuilt it? The stock oil feed plumbing on the FC does not have any restriction orifice built in to reduce oil pressure, so if this isn't a stock turbo or a 100% OEM rebuild of the stock turbo center housing rotating assembly, that could be your problem. Some (most?) aftermarket/rebuilt turbos don't like the kind of high oil pressures typical of a rotary, and lacking a pressure restrictor in the oil feed plumbing, they may blow oil thru either the hot or cold side seals. I had a similar issue with a BNR stage 3 rebuild a few years back shortly after installing it, only difference was mine was blowing oil from the cold side. After a phone call to BNR, I was advised to add a restrictor to the oil feed plumbing - that solved the problem for me.