Bad Motor Mount Causing Your Vette's Rough Idle?

Had the exact same vibration issues on my '07 Corvette last summer. Started with rough idle that got progressively worse. Initially thought it was spark plugs, but diagnostic showed a failing passenger-side motor mount causing misalignment. The mount wear was creating excessive engine movement, which affected sensor connections and threw codes. Once the mounting bracket and rubber mount were replaced, idle smoothed right out and codes cleared up. Definitely needed both front mounts replaced since they deteriorate at similar rates. This isn't just a comfort issue, bad motor mounts can lead to damaged transmission components and fuel lines if left unfixed. Mount failure typically shows up between 60-80k miles in these models. Would suggest getting it checked soon, as the symptoms you're describing match classic mount deterioration patterns. For reference, the repair took about 4 hours at the shop, including alignment verification. It's not the most complex fix, but needs proper equipment to support the engine during mount replacement.

Thanks for the detailed reply about your mount wear experience. Had the same issue and you're spot on about the rough idle symptoms. I also replaced both front mounts on my 'Vette when the passenger side failed, since the mechanic said they usually go in pairs. Just curious, what did the total repair cost look like for yours? After fixing the transmission mount and mounting bracket issues on mine, I've been monitoring for any repeat vibration issues but so far everything's stayed smooth. Did you notice any other problems pop up after the initial repair?

Just wanted to follow up, got my defective engine mount situation fully resolved! After taking it to a mechanic who actually knew what they were doing, they discovered it wasn't the mount itself but rather a loose cable connection causing those vibration issues. Only cost 95 € to fix the faulty wiring, way less than I was expecting after my mount wear experience last summer. The rough idle completely disappeared once they secured the plug connection properly. No more error codes either. Much simpler fix than having to replace motor mounts again. If you're still monitoring yours, might be worth having them check the electrical connections too, since symptoms can be really similar to rubber mount failure. Haven't had any other issues pop up since that repair. The engine runs super smooth now at idle. Just goes to show that sometimes what seems like serious mount problems can actually be something much more basic. Always good to get a thorough diagnostic before replacing major components.

Thanks everyone for the advice! Finally got my Vette's issue sorted out last week. Took it to a new mechanic who spotted the real problem right away, turned out I had both a failed motor mount and a loose sensor connection. They fixed the mounting bracket, replaced both rubber mounts, and secured all the connections properly. The whole repair took about 5 hours and cost €850 total, including parts and labor. Not cheap, but definitely worth it. The vibration issues are completely gone now and the idle is perfectly smooth. No more error codes popping up either. I learned my lesson about going to qualified mechanics who know these engines. The first shop I went to completely missed the loose connection and just wanted to replace everything. This new guy actually took the time to diagnose both problems properly. Been driving it for two weeks now with zero issues. Definitely recommend anyone with similar symptoms to get it checked sooner rather than later, waiting just risks more damage to other components.