This came out of a 99 Suburban this morning with a Vortec 350 in it. The guy that brought it to us was complaining that the motor was running very rough. Put it on the scanner and there were all kinds of problems.
Pull the plugs to see what's going on and this was the way #4, #6 and #8 looked!
After looking in the cylinders with a borescope through the spark plug holes we found this same material stuffed between the intake valves and valve seat on #4, 6, and 8.
Well after removing the upper plenum I found the problem. Apparently two of the poppet valve (fuel injector) lines had become brittle and had cracked obviously leaking fuel straight into the upper plenum. You could tell there had been a pretty strong fire under the upper intake.
So that crap you see on the plugs is melted plastic!
Pull the plugs to see what's going on and this was the way #4, #6 and #8 looked!
After looking in the cylinders with a borescope through the spark plug holes we found this same material stuffed between the intake valves and valve seat on #4, 6, and 8.
Well after removing the upper plenum I found the problem. Apparently two of the poppet valve (fuel injector) lines had become brittle and had cracked obviously leaking fuel straight into the upper plenum. You could tell there had been a pretty strong fire under the upper intake.
So that crap you see on the plugs is melted plastic!
The motor is hosed. That plastic shit is all through the motor. Chris is going to order a crate motor and we're just going to salvage the lower intake, heads and block from the hosed motor.
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