Engines are held in cars by several engine mounts, which at the most basic are typically some sort of rubber bushing or cushion. These absorb some of the vibrations and also let the engine flex a little in relation to the car. They don’t fail very often, but when they do it can cause some problems. A Honda Civic came into the shop with a complaint of a loud rattle and vibration when the car was in gear. The customer thought it was something wrong with the transmission, but one of my first suspicions proved to be correct.
This is the lower torque rod, which, while not providing primary support to the engine, helps hold it in place. As the name suggests, it controls the torque, or twist of the engine. When a car is in gear, the engine rotation will be pushing against the wheels, and in turn, twisting the engine inside the car.
With this torque rod broken, the engine was free to twist until part of it came into contact with the frame and caused the rattle and vibration. I asked a few of the other techs, and they’ve never seen this happen, so I’m not sure how. I checked on a car of similar age but higher mileage and it showed no evidence of wear or damage.
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