The engine mounts on vehicles are one of the most overlooked parts to replace, even though it has a tremendous job of holding the engine in place and absorbing unwanted vibrations.
So what do you need to look out for to diagnose bad engine mount symptoms?
When the engine mounts are worn out, you will experience more vibrations, violent shakes at startup, engine movement, clunking noise when shifting gears, and engine noise.
Since the symptoms are laid out, let me expand on them in this article so you know what to look for with a bad engine mount.
5 Bad Engine Mount Symptoms
1. Excessive Vibrations
Since the engine mounts are rubber isolators for a vehicle’s engine, it can’t do its job once it brakes or wears out.
Thus there is an increase in chassis vibration because the engine no longer has adequate isolation.
This is the first and most common sign of the engine mounts going bad.
In some cases, the engine mount’s rubber isolator is completely worn out, and at this point, the vibrations are at their worst since the engine is lying on the frame of the vehicle.
Here is a very informative video demonstrating how the vehicles sound with and without the bad engine mount:
2. Violent Shake At Startup
This symptom is most prominent when the engine mounts are torn or the rubber isolation is worn out.
At startup, the engine spins at a much slower rate, and the first combustion cycle is a bit abrupt and sudden.
The engine mounts usually absorb this initial movement, but if broken, the engine can violently shake at startup.
An interesting thing is also the more cylinders the engine has, the less violent it will be at startup since the more cylinders you have, the smoother the combustion cycle is.
It can also cause a thud or clunking noise until the engine has reached idling speed.
3. Engine Movement
One of the jobs of the engine mount is to keep the engine in its designated place, and once they are worn out, the engine can quickly start moving around when driving.
The movement usually happens when torque is applied and removed from the engine; good examples are pulling away, revving up the engine, and reapplying the accelerator when driving.
Here is an excellent example of an engine with broken motor mounts moving:
4. Clunking Noise When Shifting
This is part of the engine moving but can be heard and felt much more prominently when shifting gears.
While shifting, the engine has a short period where there is no torque applied to it by the drivetrain; thus, it settles down when the shift is done.
The engine will tilt to a side again, usually to the vehicle’s passenger side in longitudinal engine layouts and toward the car’s firewall in transverse engine layouts.
This movement, especially at higher loads and speeds, is violent enough to make clunking sounds as the metal parts of the engine mounts connect.
5. Engine Noise
When the engine mounts are broken, the engine harmonics can easily travel into the vehicle’s chassis and cause it to sound as if the engine is louder than usual.
This can be highly irritating since any semi-loose plastics in the car’s interior will vibrate at the same frequency as the engine.
You would have noticed it in the videos mentioned above as well.
How To Replace A Bad Engine Mount
If you diagnosed your vehicle with the above symptoms and it has a bad engine mount, then replacing it is the next step.
You can take it to a workshop or mechanic to replace it, or you can DIY it yourself and save a few bucks.
ChrisFix has a very informative video about it with all the tips and tricks you need to replace your engine mount:
Final Thoughts On Bad Engine Mount Symptoms
With the knowledge gained from this article, you can quickly identify the symptoms of a bad engine mount.
Hopefully, you found the article helpful and will keep your vehicle in top running condition and help you experience many trouble-free miles.
FAQs
What Do Bad Engine Mounts Sound Like?
When driving the engine, it makes a clucking or thudding noise as the engine pushes the two pieces of the engine mount into one another; it also makes harmonic rattles in the car when idling and revving the engine.
Is It OK To Drive With Bad Motor Mounts?
No, you can drive the vehicle to a mechanic or workshop but daily driving a car with a bad engine mount is a bad idea.
The constant bashing of the engine onto the frame rail can cause stress fractures in the engine block and even on the vehicle’s chassis.
Due to the excessive movement of the engine, it can also damage nearby hoses, wiring, and body panels.
Is Replacing A Motor Mount Worth It?
Yes, the driving comfort will increase immensely since fewer vibrations and sounds are going through the chassis into the vehicle’s cabin.
It can also help with future problems like the engine contacting other things under the hood, like hoses, wiring, and body panels that would also need fixing.
How Long Do Engine Mounts Usually Last?
The lifespan of an engine mount is between 5 to 10 years, depending on the duties of the vehicle and the roads it travels on.
A vehicle constantly towing a trailer and driving on unpaved surfaces will quickly deteriorate and mount on the cars.
If your vehicle is only driven on tar roads, the engine mount will dry rot before it is worn out.