Is it normal to have some oil residue in the throttle body?

 

No it should be clean. You can buy spray for this purpose. May have been sucked in by clogged oil separator in the right side valve cover. A companion hose is on the left valve cover. Intake varies by engine type fitted. But PCV system is simple. Filtered air flows from MAF side into left valve cover, thru engine, and out oil separator in right valve cover (passenger side). Vac line draws it into pleum where this foul pollution of oily fumes is burned to provide a 0.000056 mpg boost. Pull out the little spiral thing in the valve cover and clean, or shoot some carb cleaner thru it. # 3 in attached drawing.

 

With time and driving, yes it is normal to get a small amount of black residue from oily air that is being sucked up thru the valve cover. When you find this, take a can of carb cleaner and a rag, maybe even a tooth brush, and clean it all pot, this will improve your idle and throttle response.

 

Thanks guys! I have the valve covers off as I'm doing head gaskets, so I will clean and check everything as advised.

 

Post pictures as you go along, including celebration when it fires up at the end!

 

Quick question. I failed to notice which way the oil separator was facing when I removed it from the valve cover. Does the flat side with the two small **** insert facing up towards the hose or does it face down towards the rockers?

 

IMHO either way, it is just a baffle.