GMC Sierra Motor Mount Woes: Rough Idle Solutions

Had similar issues with a 2013 GMC Canyon. The rough idling and excessive vibration were clear signs of failed motor mounts. The defective engine mounts caused noticeable movement, particularly when shifting between drive and park. The rubber mount on the transmission side was completely deteriorated, and the mounting bracket showed significant wear. The issue became serious enough that it started affecting other components, including some nearby electrical connections. A proper repair required: Replacing all engine mounts (transmission mount was worst), Checking and securing loose cable connections caused by excessive movement, Realigning the engine after new mounts installation, Clearing stored engine codes The repair was significant but essential. Continuing to drive with failed mounts can lead to damaged transmission components and broken electrical connections. The vibration can also affect other engine components over time. Get it checked soon, as driving with defective engine mounts can create a chain reaction of problems. The diagnostic process is straightforward for an experienced mechanic, and the fix is routine maintenance for these trucks.

Thanks for sharing your experience. The symptoms you described match what I went through with my Sierra. Really helped me confirm it was the motor mounts before heading to the shop. Could you remember roughly what you paid for the full repair? Also curious if youve had any related issues pop up since getting it fixed. My truck has higher mileage so Im trying to budget for potential additional repairs.

After getting it fixed last month, no more vibration issues at all. The mechanic confirmed the engine mount failure was causing those problems, exactly what I suspected initially. The total repair turned out cheaper than expected at just 95 Euro for fixing a damaged cable connection near the mount area. The transmission mount and other rubber mounts were actually in decent shape, which was a relief. Once they sorted out the electrical connection, those error codes cleared up and the rough idling completely disappeared. Money well spent considering the potential damage that could have happened if left unfixed. Since the repair, the truck runs smooth as it should, with no related issues showing up. You might want to have your mechanic inspect all mounts though, given your higher mileage. Sometimes one mount failure can put extra stress on the others over time. Better to catch any potential problems early before they cause more expensive damage.

Had the same concerns about finding a reliable shop but finally took it in last week. After checking around, found a place that specializes in GMC trucks. The diagnostic confirmed what everyone here suggested, bad motor mounts causing all those vibration issues. Bill came to 450 Euro total: 280 Euro for parts (2 motor mounts needed replacement), 170 Euro labor (about 3 hours work) The transmission mount looked okay, so they left it alone. They also found and fixed a loose ground wire near one of the failed mounts, which explained those engine codes. Truck runs way smoother now, especially at stoplights. No more nasty vibrations or check engine lights. Definitely worth getting it sorted properly. The peace of mind knowing everything is secured correctly is worth the investment. Going to keep an eye on the remaining rubber mounts given the mileage, but for now, all systems are running great.