Motor mounts play a key role in driving safely and comfortably. Sometimes called engine mounts, motor mounts have two main purposes. They hold the car’s engine in place, as well as isolate vibrations that come from the engine from the rest of the car. Without motor mounts, you would feel the strong vibrations that come from the engine each time you drive.
This is typically the first sign that the engine mounts have started to go bad. As it was mentioned above, one of the main purposes of the motor mounts is to keep the engine secure. When the mounts are bad, the engine becomes insecure and may bounce about a bit. The vibration is most strongly felt on the passenger side of the car, so next time you car pool ask your passenger if they feel excessive vibrations. You could also check this on your own by occasionally resting your hand on the passenger seat as you drive.
The second most common sign that it is time to have your motor mounts replaced is excess noise coming from the engine. It is never a good thing to hear knocking and clanking or clanging noises coming from your vehicle. If you do you need to bring your car in for repairs right away.
Motor mounts ensure that the engine’s height is equal on all sides. If the mounts have gone bad the engine may sag to one side. This may cause some of the noises as well. Open the hood and see if the engine appears to be tilted. If it appears extremely tilted, it could result in an engine block. An engine block could stop your car dead in its tracks, so when you notice a misaligned engine, have it looked at immediately.
In extreme cases, the motor mounts may break off of the engine completely. This results in the engine bouncing around, which can be an extreme safety hazard. When you drive at high speeds, the engine may shift so fiercely it causes parts to fly off.
The moving of the engine due to broken or damaged motor mounts can increase the risk of hose and belt damage. This typically only happens at high speeds.
Motor mounts are rarely checked, unless symptoms you describe to the mechanic indicate that there is a problem with them. Have your motor mounts checked as soon as possible if the engine seems louder than normal, or you feel the engine vibrations more strongly, or whenever any major transmission or engine work is done.