Originally Posted By: ThirdeYe
When I got my Firebird there was a bunch of build-up under the oil cap and a bit of varnish in the oil filler neck. I attributed this to the previous owner using it mainly for short trips and the condensation/gasses built-up in that area without being burnt off. I cleaned it off 4,000 miles ago and so far it hasn't returned. There is still some varnish in the filler neck, but the valve train looks clean from what I can see through the neck. In short, the black junk you see on the baffle may not necessarily mean the rest of the engine is sludged/varnished. BTW, is this in one of the sludge-prone Toyota engines?
No, it is 1Nz-Fe, 1.5lt engine.
I do not want to open the valve cover yet, and trying to clean from outside might add dirt.