2018 Silverado vibrating/pulsating/shimmy?

[Steve M.]

Hey guys, 

    New here but been reading this forum for a long time. I recently just traded up a month ago and got a 2018 Silverado 1500 custom crew cab,5.3L 6spd 4x4 with 20k miles. I was really excited about the truck and pleased til I resumed my daily highway work commute the following Monday.   I instantly noticed a sort of vibration going down the highway starting at 65mph to 75Mph, it’s odd , feels like a out of balance tire... but not in the steering wheel... you feel it in the seat, gas pedal, cab.  So I took it in with that complaint, the service advisor told me that they didn’t feel it, said it’s just going from 8cyl-4cyl mode and that’s just the way it is. Also said well it has 20’s so that’s what you’re probably referring to, just a rough ride. I said it does it in manual mode in 5th gear, it’s still there when the truck is stuck in v8 mode. Basically blew me off. Kinda looking where I should go from here. Any advice or help is greatly appreciated. It’s drives me crazy and I just figure that the first time in they don’t want to mess with it and tell everyone that. 

[m3n00b]

5 minutes ago, Steve M. said:

Hey guys, 

 

    New here but been reading this forum for a long time. I recently just traded up a month ago and got a 2018 Silverado 1500 custom crew cab,5.3L 6spd 4x4 with 20k miles. I was really excited about the truck and pleased til I resumed my daily highway work commute the following Monday.   I instantly noticed a sort of vibration going down the highway starting at 65mph to 75Mph, it’s odd , feels like a out of balance tire... but not in the steering wheel... you feel it in the seat, gas pedal, cab.  So I took it in with that complaint, the service advisor told me that they didn’t feel it, said it’s just going from 8cyl-4cyl mode and that’s just the way it is. Also said well it has 20’s so that’s what you’re probably referring to, just a rough ride. I said it does it in manual mode in 5th gear, it’s still there when the truck is stuck in v8 mode. Basically blew me off. Kinda looking where I should go from here. Any advice or help is greatly appreciated. It’s drives me crazy and I just figure that the first time in they don’t want to mess with it and tell everyone that. 

Does it go on for 1 second off for 1 second over and over again?

[Steve M.]

No it doesn’t, not that I’ve noticed. 

[carnau]

47 minutes ago, Steve M. said:

Hey guys, 

    New here but been reading this forum for a long time. I recently just traded up a month ago and got a 2018 Silverado 1500 custom crew cab,5.3L 6spd 4x4 with 20k miles. I was really excited about the truck and pleased til I resumed my daily highway work commute the following Monday.   I instantly noticed a sort of vibration going down the highway starting at 65mph to 75Mph, it’s odd , feels like a out of balance tire... but not in the steering wheel... you feel it in the seat, gas pedal, cab.  So I took it in with that complaint, the service advisor told me that they didn’t feel it, said it’s just going from 8cyl-4cyl mode and that’s just the way it is. Also said well it has 20’s so that’s what you’re probably referring to, just a rough ride. I said it does it in manual mode in 5th gear, it’s still there when the truck is stuck in v8 mode. Basically blew me off. Kinda looking where I should go from here. Any advice or help is greatly appreciated. It’s drives me crazy and I just figure that the first time in they don’t want to mess with it and tell everyone that. 

Take it back to the dealer and have a tech ride with you and show him the vibration. You let them off the hook too easy.