2 of 8 spark plugs black
TECH Fanatic
Joined: Mar 2014
Posts: 1,266
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Look at the harnesses that are plugged directly into the coils. It sounds like they are switched side to side. The plug with the red wire goes to number two and lays out accordingly. The plug with the purple wire goes to number one and lays out accordingly. Its a mistake that gets over looked more than you think. Motor will run fairly good too. Won't break up till you hit like 6000rpm. Will sit and idle fine too. Hard to believe it doesnt pop and bang bad but it doesn't at all. If you have a stock pmc then you most likely don't have individual cylinder timing. Bet its the harnesses.
Look at the harnesses that are plugged directly into the coils. It sounds like they are switched side to side. The plug with the red wire goes to number two and lays out accordingly. The plug with the purple wire goes to number one and lays out accordingly. Its a mistake that gets over looked more than you think. Motor will run fairly good too. Won't break up till you hit like 6000rpm. Will sit and idle fine too. Hard to believe it doesnt pop and bang bad but it doesn't at all. If you have a stock pmc then you most likely don't have individual cylinder timing. Bet its the harnesses.
While you were.. just checked not harness, Compression, plugs, wires, coils, inj, rail, and oil is about even across all of the cylinders and even put new rtv seal on rocker bolts let it sit since last night and took it out tonight with yet another set of plugs and took them out after about 25 to 30 miles and once again black...
Could it be pcv related just noticed the shop must have put the valve cover hose to the intake instead of the tb and well never even ran one from the valley cover to what should be the intake... Could that be sucking all the oil from the valve cover and throwing to the back of the intake causing 5 and 7 to flood with oil? And if so could this have caused damage? Explains why they all had oil on the threads i guess...
Could it be pcv related just noticed the shop must have put the valve cover hose to the intake instead of the tb and well never even ran one from the valley cover to what should be the intake... Could that be sucking all the oil from the valve cover and throwing to the back of the intake causing 5 and 7 to flood with oil? And if so could this have caused damage? Explains why they all had oil on the threads i guess...
i assume you have the newer ls6 or gen IV style PCV system...
fresh air comes from before the throttle body, or at the throttle body, and then goes into the valve cover. dirty air goes from the valley cover (through the baffles in the cover) into into the intake manifold.
if you had an older system, you might have a hose coming from the other valve cover and a PCV valve, but the principle is similar.
it won't cause damage, and i guess it might be possible it caused the two plugs to foul. it would have helped had you posted a pic of the plugs, generally oil fouling looks wet.
