Well, the rubber in your mounts could be worn down? And yes, you would definitely notice the engine going wild if a mount was broke, let alone two. My buddy has a Mercury cougar and his front mount broke where the bolts that hold the mount onto the engine are. So at first glance, the mount looks fine, but look closer and it's he mount's mount, lol, that was busted. And when you pop the hood and watch the engine when he put it into gear, the engine moves about 8 inches. Then shakes like crazy when driving.