oil in throttle body

[jeb]

'90 3.0 4runner has very small amount of oil in throttle body. What could be causing this? Not burning oil, at least not at plug level, they are clean and white/gray looking. I'd check the PCV valve if I could get to it. Could this be the cause?

 

[ToolmanJohn]

Oil Vapor condensation

You are right about it may be the PCV Valve (Positive Crankcase Ventilation) allowing oil through instead of regular crankcase pressure buildup.

Also, some small amount of oil will end up as vapor and condense in the throttle body because it will cool faster than the rest of the engine.

I've seen this on every vehicle I've owned, so it's really not a big deal unless it's a substantial amount of oil, in which case it could be valvetrain problems with oil blow-by.

Replace the PCV valve first, it's cheap.

 

[jeb]

I wouldn't say it's a lot, but you can see it. Black for some reason. Also wouldn't say film, but not running or puddle either. No smoke, probably nothing to worry about like you said. At 200,000 I was curious.