Time for new engine mounts?

[bfourman]

My 09 6.0 with 220k did the same. I replaced both motor mounts with stock rubber units and the trans mount. It helped with the random rough idle and felt better under acceleration. They didn’t look like hydro filled but I don’t know. The rubber was certainly broken down after 220k.

Still had a rough idle, so I pulled the upper intake and probably drained 1/2 pint of oil out. I added a catch can and the idle cleared up tremendously after a Seafoam upper intake cleaning. Every now and then it will stumble but I chalk that up to the weird 6.0 thing.



The wetness is from copious amounts of PB Blaster.

 

[91RS]

They don’t have to be broken to cause a vibration issue. The mounts will collapse over time due to age, this will cause vibration. I’d recommend replacing both if you’re over 100k miles but if you really only want to replace one replace the right (passenger) side mount if you have vibration in Drive but not in Reverse. If you have vibration in both them you need both mounts.

 

[jsoltren]

For the 6.0L 2500 with the 6L90 the engine and transmission mount part numbers respectively are 25828247 and 15113134.

 

[iamdub]

Those are non-hydraulic mounts. In fact, they're the mounts intended for the trucks with the trailering package and should have a red stripe painted on them. I recently ordered a pair of these for my brother's '06 Sierra CC. I didn't think they'd put the hydraulic mounts on a 2500. His original mounts had 181,000 miles on them and were still in usable condition. I replaced them because the engine was out for other repairs and his truck is 4WD so replacing them later would've been a huge PITA.