71zedder

2007 sierra z71 crew cab. LH6 motor aluminum block with AFM. 63000kms. Bought used last summer and in less than 3000kms the add engine oil light came on. Not impressed. No smoke anytime. Been on oil consumption list at dealer since last Sept(2010). Dealer says 1liter in 3200kms is acceptable to GM. But not to me. Here are my numbers. 0.8liters in 2633kms, 0.8liters in 1588kms, 0.35liters in 991kms, 0.5liters in 764kms, oil change when service life reached 5% (guess all it needed was a filter LOL oil already changed), then 1.2liters in 755kms- (not sure what the story is here its a bit high). At cold start up I have slight lifter tap or piston slap. Mostly driving to work on rural roads so AFM is on a lot. But, seems worse when i'm idling in cold weather to warm up. No AFM when idling so can't say its related but since discussing this with other GM truck owners with 5.3l, some with no afm, seems like most are using a little oil, around a liter between changes. GM can't really expect people to swallow that this is normal, even at 1 liter/3200kms. It's going somewhere and will cause problems later, either sludge or killed catalytic converters etc.. Have been loyal to GM for 20 years but my next purchase will depend on how this is handled.