What are the Symptoms of a bad Engine Mount? | How to replace a Motor Mount?

The engine mount is one of the major parts of a vehicle or vehicle. It connects the vehicle engine to the vehicle boy or frame. The engine mounts assist to hold the engine in its place. They absorb engine noise, vibration, and shocks during engine operation, which is essential to avoid engine and vehicle body damage. This article mainly explains the bad engine mount symptoms, its causes, replacement cost, and function.

What Is an Engine Mount?

The engine mount is used to hold the engine in its place and prevent it from vibrating. In maximum vehicle models, the transmission and engine are bolted together and held by three or four engine mounts. The mount used to hold the engine is known as the engine mount, while the mount used to hold the transmission is known as the transmission mount.

Engine Mount

In most car models, two or three mounts are used to hold the engine, while one mount is used to hold the transmission system.  

One end of your mount is bolted to your vehicle body, while another end is used to hold the engine. An operating engine generates extreme vibration because it contains multiple rotating and moving components.

The main function of the engine mounts is to keep the engine in its original position and lessen engine vibrations experienced inside the vehicle. The rubber material is most commonly used for manufacturing engine mounts, so there couldn’t be direct metal contact between the vehicle body and the engine.

Engine mounts do not require regular maintenance or repair. You need to replace it only when it is worn or damaged.

The major issues with engine mounts are cracking or loosening rubber parts or fluid leaking from liquid-filled mounts.

When the engine mount fails, it produces different symptoms such as poor acceleration, poor engine performance, extreme vibration of the engine, visible wear, unusual noise from the engine compartment, and the engine jumps at idle.

Types of Motor Mounts

The motor mounts have the following major types:

  • Metal Motor Mount
  • Hydraulic Motor Mount
  • Solid Rubber Motor Mount
  • Electronic Motor Mount
  • Rigid Engine Mount
  • Resilient Mount
  • Polyurethane (PU) Motor Mount

1) Metal Motor Mount

These motor mounts generate a rigid and strong connection between the car body and engine, allowing plenty of power to be moved to the wheels while remaining stiff under heavy loads. Metal motor mounts transfer the most engine noise and vibration due to their metal-to-metal connections.

Metal Motor Mount

2) Hydraulic Motor Mount

This type of motor mount is filled with a liquid or fluid gel. This mount is commonly used to absorb and minimize engine vibration before it reaches the car body.

Hydraulic engine mount

Hydraulic motor mounts are usually used in the construction, marine, and automotive industries.

3) Solid Rubber Motor Mount

A solid rubber cushion is used for the manufacturing of solid rubber motor mounts. The steel-backed plates are used to attach these mounts to the engine transmission and chassis. These mounts are most commonly used in trucks and cars. The combination of different materials improves flexibility, reduces system shocks, and improves engine motor service life. 

Solid Rubber Motor Mount

This type of motor mount has high durability and absorbs noise and vibration well. It is relatively inexpensive.

4) Electronic Motor Mount

These types of motor mounts are intended to minimize vibration and noise by varying the stiffness and damping characteristics of the mount based on your car’s speed and load. This information about your car is monitored and reported back to the powertrain control module (PCM) via sensors.

Electronic Motor Mount5) Rigid Engine Mount

This mount attaches to your vehicle frame with screws or fasteners. Some rigid mounts may be manufactured into the equipment or permanently welded in the desired location.

Rigid Mount

6) Resilient Mount

This motor mount has a rubber or insulating layer inside the mount and motor. The material used for the construction of this mount reduces engine vibration and noise as well as extends the life of the engine and all associated components.

Resilient Mounts

7) Polyurethane Motor Mount

It is a durable alternative to the rubber engine mount, providing the combined benefits of high-strength steel and rubber engine mounts. These features improve performance and road feel.

Polyurethane engine Mount

These mounts are very costly. The polyurethane mount has poor heat resistance, which may generate issues in automotive applications.

Symptoms of a Bad Motor Mount

As the engine mount goes bad, it generates one of the below-given symptoms:

  • Abnormal vibrations
  • Bouncing off the engine
  • Violent noise from under the hood
  • Rocky start
  • Engine jumps at idle
  • Damaged engine block
  • Visible wear
  • Unnecessary engine movement

1) Abnormal Vibrations

Abnormal engine vibration is one of the major symptoms of a bad engine mount. Engine mounts are designed to dampen and reduce the vibration of the engine.

When you start the engine, and if it generates more noise and vibration than normal, this is a clear symptom that your engine mounts are worn, and you may need to replace them. Increased vibration can cause the engine to become louder than normal, and if this continues for a long period of time, extensive engine damage can result.

Therefore, when your engine mount goes bad or fails, you should replace it immediately to prevent engine damage.

2) Bouncing off the engine

Any movement or wobble in the engine compartment is an indication that you need to replace the mounts. The function of the engine mounts is to prevent your engine from moving and keep it in its place.  

The faulty mounts don’t hold the engine due to that your engine will be free to move in either direction. In such conditions, vibrational noise occurs mainly during acceleration, which causes the engine to vibrate excessively.

It makes a rattling noise when the engine is loose. It can also damage sensitive parts of the engine.

3) Violent Noise from Under the Hood

If your vehicle engine mount goes bad, noise may be generated in the engine compartment. When your mount goes bad, it doesn’t properly hold the engine in its place, which may cause to produce extreme noise in the engine compartment.

The motor mounts assist in decreasing engine noise. Therefore, when driving at high speed or when overcoming obstacles on the road, the engine may vibrate and generate noise.  

You may hear a knock, a phone call, or other possible noises due to faulty mounts. These noises are usually generated because your engine is no longer held in its original position, so it shifts to different directions based on the force of movement.

4) Rocky Start

When you turn on the vehicle, you may notice extreme lurch that is not healthy to the touch or audible. This is also a common symptom of worn mounts. This lurch usually converts into a constant vibration but can also occur with the ignition off.

5) Engine Jumps at Idle

If the engine knocks at idle when you open the hood, the cause may be faulty engine mounts. Remember that your engine may jump at idle for many other reasons. Therefore, when your engine starts jumping, you should immediately contact a professional to fix the issue properly.

6) Damaged Engine Block

A damaged engine block is one of the clear symptoms of a bad motor mount. Actually, it’s because the vehicle mount has long been damaged and turned into a catastrophic failure through the negligence of the fault. This can cause the entire engine in the car to jerk.

In this case, the movement of the engine when driving at high speeds can damage the engine block, which can also affect other engine parts. Driving the vehicle can be dangerous if not remedied immediately.

Read More: Function and Working of Engine Block

7) Visible Wear

The metal parts of the mounts change their appearance over time. Therefore, visible cracks or corrosion on the engine mount is one of the clear symptoms that the engine mount is damaged and has limited effectiveness, especially if the cracks are severe.

The effectiveness of the mounts depends on their design and shape. If you notice signs of a bad motor mount, you should replace it as soon as possible.  

8) Unnecessary Engine Movement

The engine of your vehicle attaches with mounts through multiple bolts. These bolts hold the engine in its place and prevent it from moving. Therefore, the bad mounts may cause the motor to lean or bend, which is not good. When the motor is leaned or bent, it starts to produce unnecessary noise and vibration.

This issue can be determined by listening to the sounds coming from the engine compartment. In most cases, you may observe excessive vibration. Therefore, you should always inspect your engine regularly.

If the engine is slightly bent or tilted, it probably doesn’t matter, but if it’s tilted too much, the engine may fail. Inspect and replace the mount if it has expired.

Causes of a bad Engine Mount

  • Wrong installation of the mount
  • Age and wear of engine mount
  • Over-revving the gears and improper use of the clutch may lead to serious damage to the motor mounts.
  • Your car accident which has the ability to damage the mounts
  • The leakage of engine oil or coolant onto the mounts
  • Corrosion buildup inside the mounts

Motor Mount Location

The mounts are usually located on the bottom side of the engine, but in the case of some models, they may be installed on the top of the engine. Some cars only have two mounts …. One on each side of the engine, while some models have three or four mounts.

How to replace an Engine Mount?

  • First of all, wear safety gloves and glasses.
  • Locate the engine mount. The mounts are usually located on the bottom side of the engine.
  • Place the jack under the oil pan. Once properly positioned, lift the pan up until it just touches the engine’s bottom side. This is performed to support the engine. Now you can easily access your vehicle’s mounts. Properly inspect all the mounts to find the faulty mount.
  • Use a wrench to remove the through-bolts of the engine mounts. Hold the bolt head with a wrench and slowly remove it. One end of the mount is attached to the engine, while another end is attached to the vehicle frame.
  • Use a suitable socket to remove the nuts from the mount.
  • After all the above steps, you can easily take off the faulty mount.
  • Purchase a new mount and compare it with the old one. Don’t forget to test the new mount before installing it.
  • After testing, now properly install the new mount in its original place. It’s merely a reverse process of how you remove the old mount. Use new bolts and nuts to install the mount onto your engine.

Engine Mount Replacement Cost

The replacement cost of the motor mount varies according to your vehicle model, labor cost, and type of the part brand.

The average replacement cost of the engine mount is from $90 to $720. In this cost, the labor cost is from $60 to $400, while the engine mount cost is from $30 to $340.

How to Diagnose Bad Car Engine Mounts

FAQ Section

What is the function of the engine mount?

The main function of engine mounts is to fix the engine in its place and absorb vibration and noise while the engine is working. Engine mounts and anti-vibration mounts are important to prevent engine damage and improve rider comfort. In most cars, two or three mounts are used to hold the engine, while one mount is used to hold the transmission system.  

Can a bad engine mount affect the transmission?

Yes, defective engine mounts can disturb the transmission through the extreme movement of the transmission and engine, which can lead to excessive vibration over time.

How many engine mounts are there?

The number of engine mounts in a car depends on the vehicle model. There are usually 3 to 4 engine mounts, but it depends on the stability and size of the engine. Few vehicle models may have four mounts due to the inverted position of the engine compared to the position of the various parts of the vehicle body. The mounts are designed to fix the engine in its place and prevent engine vibration.  

How long does the engine mount last?

The engine mount life cycle depends on its maintenance and driving conditions. It is recommended to replace the mount after 200,000 miles. However, your hydraulic mounts may fail earlier. 

What are the symptoms of a bad Engine Mount?

When the engine mount goes bad, it generates one or more of the below-given symptoms:

  • Abnormal vibrations
  • Unnecessary engine movement
  • Bouncing off the engine
  • Visible wear
  • Violent Noise from under the hood
  • Damaged engine block
  • Rocky start
  • Engine jumps at idle

What are the types of the engine mounts?

  • Polyurethane (PU) Motor Mount
  • Metal Motor Mount
  • Resilient Mount
  • Hydraulic Motor Mount
  • Rigid Engine Mount
  • Electronic Motor Mount
  • Solid Rubber Motor Mount

Leave a Comment