Starting to feel vibration in 4cyl mode

[tom3]

About to hit 30K miles on the 2019 with 5.3 standard motor. Has been totally smooth in 8 and 4 cylinder mode at cruising speeds up to now. Wouldn't know it even had the AFM deal. Just starting to feel some engine vibration in 4 cyl mode on the highway at easy cruise. Hasn't used a drop of oil since new, no new noises. Would this be normal? Anyone actually notice this in their similar Tahoe/Yukon?

 

[Doubeleive]

About to hit 30K miles on the 2019 with 5.3 standard motor. Has been totally smooth in 8 and 4 cylinder mode at cruising speeds up to now. Wouldn't know it even had the AFM deal. Just starting to feel some engine vibration in 4 cyl mode on the highway at easy cruise. Hasn't used a drop of oil since new, no new noises. Would this be normal? Anyone actually notice this in their similar Tahoe/Yukon?

I could always tell when it hits v4 mode and hear it, you are probably just now getting a feel for it, @30k you could do a injection/intake service that might help
my butt & foot sensor is pretty sensitive even a slight difference I can feel, my fix is it is turned off (tuned out) v8 24/7

 

[89Suburban]

Turn that AFM off ASAP.

 

[swathdiver]

About to hit 30K miles on the 2019 with 5.3 standard motor. Has been totally smooth in 8 and 4 cylinder mode at cruising speeds up to now. Wouldn't know it even had the AFM deal. Just starting to feel some engine vibration in 4 cyl mode on the highway at easy cruise. Hasn't used a drop of oil since new, no new noises. Would this be normal? Anyone actually notice this in their similar Tahoe/Yukon?

Check the motor mount on the driver's side. Are you running Top Tier fuel all the time? Try a couple tanks of Chevron 93 or E85 if you have a FlexFuel motor and see if it goes away.

 

[B-train]

I have a RANGE device I don't need anymore if interested.....Keep that fella in V8, or change the oil very religiously.

My guess would be on intake cleaning needed. These carbon up the valves due to the direct injection. Either have a COMPETENT person do it, or buy a can of seafoam intake cleaner with the long straw and have someone help you do it. The whole process of spraying the can takes about 10 minutes. After that, it's an easy 1 person job to do the heat soak and 'spirited' driving.

 

[17 Yukon Denali]

I agree, check your motor mounts. I had the top end rebuilt recently because of a failed lifter. Started to shudder and vibrate Friday. dropped it back a dealer yesterday. turns out it was a fouled plug and bad mounts. The mounts aren't an easy replacement from what I've seen so I'm just having them do it. $1081 installed.