How to Diagnose Bad Motor Mounts Yourself
Do you feel a sudden thud when you shift your vehicle into drive? Jerking, Vibrations, Engine Movement, and Clunking Sounds are common signs of bad motor mounts. Learn how to diagnose them.
What is an Engine Mount?
Engine mounts or motor mounts are metal and rubber devices that secure the engine to the chassis. As your engine works to generate power and torque, they absorb the vibrations and prevent some parts from moving around.
Engine or motor mounts are available in different shapes and sizes. Some cars have them located at the front from where they support the weight of the engine. Others have them fixed at the bottom where they prevent the engine from rocking back and forth. Watch this video to learn how to diagnose a bad engine mount.
Symptoms of a Failing or Bad Engine Mount
When your engine mount fails, you’ll notice a few things while driving the car. Below are some of the signs and signs of a bad motor mount that needs to be replaced.
1. Jerking When You Shift
If you shift your vehicle into Drive or Reverse and feel a sudden jerk, it could be a sign that you have a bad engine mount. The jerking is caused by the movement of the engine whenever you change gears. You may also feel the entire vehicle move.
2. Excessive Vibrations
Another sign of a failing or bad engine mount is excessive vibrations in the cabin, steering wheel, or floorboard when you come to a stop. This means that the rubber part of the mount isn’t doing its job to absorb the vibrations that are coming from the engine.
3. Engine Movement
Engine mounts or motor mounts are designed to secure the engine in its bay. When broken or worn out, they can cause the engine to move backwards, forward, or side to side. To check for engine movement, engage the parking brake and push on the brake pedal real hard.
Shift the vehicle into Reverse and press on the accelerator. Have someone watch the engine from a safe distance for movement. If they notice significant shifts in its position, it’s a sign that your engine mount or transmission mount is damaged.
4. Clunking Sounds
The vibrations and engine movements caused by an engine mount that’s worn out could be accompanied by clunking or thudding noises. You may hear similar sounds when waiting at a stop light, accelerating, or shifting the vehicle into drive or reverse.
How to Diagnose Failing or Bad Motor Mounts
Noticing the signs and symptoms of a failing motor mount or engine mount may not be enough. It’s always best to conduct a visual inspection yourself.
1. Check for Cracks and Dry Rot
Take a look at your mount to see if it has any large cracks or dry rot. Sometimes, there could be cracks in the coating on the metal. These aren’t a big deal. However, major cracks and excessive dry rot should be a major concern.
2. Check for Oil Leaks
Oil leaks can compromise the integrity of the rubber found on the engine mount. Check to see if there’s any fluid that may have gotten to it. You’ll want to fix any oil leaks before replacing the mount because that can still ruin a new mount.
3. Pry the Engine Mount
If you have a motor mount that’s inaccessible, place a pry bar at the point where it supports the engine. Move the pry bar up and down to check for excessive movement and also to see whether the mount has any dry rot or major rubber cracks.
Some engine mounts use hydraulic fluid to help absorb vibrations and impact. Check to see if the fluid is leaking. All in all, if your engine mount is dry rotted or old, you’re better off replacing it.
Related Content:
- Why is My Car Leaking Oil?
- What Fluid is Leaking from My Car?
- How to Replace Upper Engine Mount
- How to Replace Rear Engine Mount
I have a Hyundai sonata 2007 that jerks when stop at traffic lights. What could be the problem
Idk if you’re still looking for an answer but your description of the issue is far too vague to serve as a diagnostic tool. What do you mean by the car “jerks when stop at traffic lights”? Is the “jerking” the rpm surging or does it feel like the engine is “loose” and trying to get away from your car?