Exhaustr hits flooring

[Onequik89]

This is my first post here. I have been looking on here for quite some time trying to find this answer with no luck. I have a 2009 GMC Sierrra SLT Crew cab with the 5.3 OHV motor. When i give my truck more than half throttle from a stop or if i am pulling a load, the flange on the drivers side where the manifold connects to the midpipe will hit the floor. Anyone else have an issue with this happening?

[Doug_Scott]

open the hood, get someone inside the truck to run the engine, put it into drive, hold brake pedal down hard, and then step on gas to load the engine. Watch the motor mounts and see if one is broken. Good mounts will let the engine move slightly, broken mounts will allow the engine to jump up and hit the floor of the cab. Note that as long as it is only one broken mount, the engine will only jump up in either drive or in reverse, not both. Compare the engine reaction in both drive and reverse to see the difference. If mount is broken, change them both. The side that is not broken has be over -stressed due to excessive movement.