i have a 2009 1500 LTZ Z71 with 75,000 miles. I have been hearing a knocking sound when i accelerate from a red light that seems to be coming from my passenger side and possibly from the rear. Hard to tell when im driving. It only knocks 3 times and when i accelerate from a stop and usually after i have been driving for a while. Never rite after i start it and take off. Anybody know what the knocking is?

 

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It may be a main bearing issue. It could also be a lack of oil to the lifter(s). These are merely suggestions, not a diagnosis. I encourage you to take the vehicle in for an inspection. A certified technician should be able to offer an accurate diagnosis with a physical inspection.

If you have additional questions, please feel free to contact me.

Louis
GM Customer Service