When 1st cranking truck and put in drive motors rrev up and shifts hard to second. occasionally when i out in reverse it will sit there n not shift in. then when it does it shifts hard. when accelerating the truck it sounds like a clattering sound under drivers side under hood. tried different type of gasoline and nothing changes. gmac needs to do a recall on both of these items. i am very disappointed in my gmc and gmac
The sierra surges from park to reverse and drive. i bumped a vehicle today, and the surge has become an issue this week and there is not even 9,000 miles on the truck. the afm is rough shifting between v8 and v4 mode too. none of this was an issue until recently. my speakers also vibrate like a blown speaker on high definition radio, but not on regular radio stations.
Fuel injection seals #4 o-ring split - leaking fuel - pooling gas on manifold. took vehicle in for smell of gas, lack of acceleration and poor gas mileage. this is known issue based on the service bulletin 18-na-137 - vehicle has less than 6000 miles