question about cleaning the throttle body on a sc2?

I've seen this on my car, nothing to worry about, probably a lot of short trips, and not enough long highway trips.

today I cleaned the throttle body on my wife's 1997 sc2 and when I had it apart I noticed that there was a black coating all over the throttle body and into the intake manifold. I sprayed it with carb cleaner to clean it and got all the black stuff off the throttle body but could not clean the intake manifold as well. is this black stuff normal or is something wrong with the car? thanks carmine

clean it and

You really should use throttle body cleaner rather than carb clean. The coating is normal. Cleaning the plate does what you need it to.

Ken

It is normal. The black stuff is introduced into he intake tract by the PCV system. It is the gunk that has evaporated or been blown into the crankcase. The PCV system sucks it up and feeds it into the intake tract. The intake tract is much cooler than the crankcase, so when the "stuff" is introduced into the intake tract some of it condenses on the cool metal parts. As long as it is not causing the throttle plate to stick, or blocking the idle air passage, it is harmless. Some manufacturers include an "anti buildup" coating on the throttle body. Ford in particular specifically says not to clean the throttle body - but most people eventually find it necessary anyhow. Using harsh chemicals like carb cleaner can damage this coating. There are chemicals made especially for this tasks ("throttle body cleaners"). I usually just soak a soft rag in WD-40 and gently wipe the stuff out.

Ed