Hello all, i have a 2006 cobalt ss/sc with stage 2 upgrade and GMPP header and exhaust. Every mod on my car is GM. My car has been loosing power, doing the knock retard thing for months, and on occasion, spitting out the dip stick. My car in the last 3 months has had new piston rings, new cylinder sleeve in #3 and #4 and new #4 piston because the old one cracked in 4 places. I got my car back yesterday and its sill not fixed, its still doing the knock retard thing. 7 degrees knock retard in some cases( i had my car hooked up to hptuners to see what is was doing when it was loosing power durring WOT). The tune is Stock stage ii, the pully is the 3" stage ii pully, the plugs are new, i have no fricken idea whats wrong with this car and its looking like neither does GM. Anyone have any ideas as to what the problem is?

-shawn

 

Did you log the intake temperatures?
As it knocks, maybe something is wrong with the intercooling.
(read somewhere that in some occasions the IC pump was wired in reverse.... )

 

have you had your car properly tunned to keep ur AFR nice and happy?

 

have you tried getting rid of it... should be lemoned