2011 Suburban LT - Rough Idle (Tensioner?)

[yolo33]

Howdy all!

Thanks again for the previous service advice on my 2011 Suburban. 126K I ended up having all new (plugs, wires, BG Injector Service, BH 4x4 Service, Throttle Body Cleaning, MAF Cleaning, filters, Transmission Service, fluid flushes...etc)

I noticed that I'm still having a slightly rough idle or vibration during idle. (You can sit in the car and feel it idling) RPM needle had been jumping prior to all the service above, however that has since been resolved. I did notice yesterday that the belt tensioner moves back and forth very mildly with every rotation.

My question is, should the tensioner have play and lightly move while idling? If not, could this cause the rough idle or what else do I need to be looking at?

Edit: Here is a video of what I’m seeing. https://streamable.com/crwrh2

 

[j91z28d1]

I don't know that you'd feel it, but something to keep an eye on is the balancer goes out on these. if you're seeing the tensioner moving around. look down at the crank pulley, the big one at the bottom. see if you see any wobbling in it.

the part the belt rides in is only connected to the inner hub with rubber, over time the rubber goes bad and the outter moves around. good to catch early as it can move around a lot before it completely fails.


just something to check

 

[swathdiver]

Howdy all!

Thanks again for the previous service advice on my 2011 Suburban. 126K I ended up having all new (plugs, wires, BG Injector Service, BH 4x4 Service, Throttle Body Cleaning, MAF Cleaning, filters, Transmission Service, fluid flushes...etc)

I noticed that I'm still having a slightly rough idle or vibration during idle. (You can sit in the car and feel it idling) RPM needle had been jumping prior to all the service above, however that has since been resolved. I did notice yesterday that the belt tensioner moves back and forth very mildly with every rotation.

My question is, should the tensioner have play and lightly move while idling? If not, could this cause the rough idle or what else do I need to be looking at?

Edit: Here is a video of what I’m seeing. https://streamable.com/crwrh2

Age not mileage in your case I would change the tensioner and idler pulley. Your vibration is probably coming from your busted driver's side engine mount.

 

[Joseph Garcia]

A faulty/worn belt tensioner won't cause a rough idle. But, it can cause the belt to come off, potentially stranding you out on the road. The tensioner is relatively inexpensive, and it is easy to replace.

 

[91RS]

Engine mounts.