Ok well i have a 2010 5.3l cc chevy i noticed the other day start up was running ruf for like 15 seconds thought maybe bad gas freah tank of 93 still doing it change plugs and noticed abit of oil on some of the threads of the plug blo-by?? It has 15,000 miles on it talked to a friend of mine he says it maybe because at 2500 miles on it i started using mobil-1 and you can't break in a eng on synthetic????? Is this true am i screwed or can i start running conv oil ?????

 

The engine is pretty much completely broken in after 1000 miles, so thats not your problem. You should have basically no blow-by with a stock engine with so few miles. If its still under warranty take it to the dealership and let them do their thing.

 

Synthetic oil will work for breaking in a factory engine my old 99' corvette came with mobile 1 from day one with 6 miles on the car from chevy. No oil on the plugs ever. If you install a new camshaft it is usually recomended that you use a break in oil with ddp like valvoline vr1 or conventional oil with additive with ddp like cam shield. When you rebuild an engine and re hone the cylinders you should use conventional oil to break in the rings after 15 min of running the engine you can change the oil to synthetic if you want to. Is the truck still under warranty?

 

yep still under warrenty has a cat-back a volant cai and a custom tune think i will have any trouble if i take it in

 

I'd reflash to the stock tune if possible.