mike finefrock

Thank you for the reply. I found that bulletin and I did inspect the mount myself but I did not remove it. I did not see any debris.

2020 GMC Sierra 1500 w/5.3 and 10 speed. Hello, I have noticed a distinct vibration felt in the seat and on the floor when RPM's are very low. I had it at the dealer and got what everyone else seems to get on this forum. "Normal 'feature' for the truck with DFM... " Since then the weather has turned colder and the truck does not get up to operating temperature quite as quickly. Now that i drive farther with the coolant temperature in the 170° to 185° F range, I noticed that the vibration is completely gone at this temperature but when it does get to normal temp, the vibration comes back. I think I can tell that the DFM is still working based on the MPGs. I was thinking about changing the thermostat to a slightly cooler one. thoughts?