05 CC 5.3L question

[steve summers]

I have a question/concern on my 05 GMC CC with 5.3L. First I've noticed the last couple of weeks that it is occasionally pinging really bad from a heavy start, so sitting at a stoplight and gas it a bit more than normal, but not mashing the pedal, it pings really bad so I let off. It isn't consistent though.

 

The second thing I've noticed, when on the highway and it kicks down a gear and the motor revs out I see a pretty fair amount of smoke coming out of the exhaust in the rear view mirror. It doesn't appear to be blue smoke but it is hard to tell from the mirror. I did have a buddy following me the other day describe the smoke as black.

 

The motor has about 12K miles on it, the only mods is a K+N drop in filter, and 20" wheels. Is there anything to worry about? I've thought about taking it in to the dealer as the steering shaft is clunking as well.

[GM-Tech]

Lots of things could be going on here. I'd say you should probably take it in and let them check it out.

[steve summers]

Thought I would post an update. I haven't been to the dealer yet but did make a 500+ mile trip last weekend. The truck ran OK for the first leg of the trip, I had some time to kill so I was cruising the automotive aisles at Wal-Mart and saw Berrymans on sale for 2 cans for $5. I typically try to run a couple of cans through the fuel systems ocassionally but hadn't done so recently so I bought a couple of cans and added it to the tank. The truck ran much better on the way back so I'm not sure if I had a dirty injector, or maybe just some bad gas. Regardless I am still going to have the Dealer check it.