When the engine on a vehicle is operating, it produces a lot of vibration. If not for certain components known as motor mounts (or engine mounts), the car vibration would make the whole experience very dreadful for the people inside.
It is easy to overlook how frequently bad motor mounts are ignored. They can save you a lot of money when you start to look for car mounts early. Ignoring the problem is sure to create a bigger dent in your pocket, even though changing the motor mount isn’t that cheap to begin with.
What Are Motor Mounts?
An engine is made of hundreds of different parts, all operating in unison to pull your vehicle forward.
The rattling is due to the car’s starting parts moving, which causes the engine to shake at the same time. Without the motor mounts on engines, this shaft would rattle the occupants and the engine into madness.
Motor mounts or engine mounts are fixtures that hold the engine onto the frame of the vehicle. They serve to contain the engine and dampen the shocks and vibrations, which allows you to have a smooth drive.
How Many Motor Mounts Are on a Car?
Motor mounts on cars tend to be in the range of two and four. In the case of one motor mount being broken or worn out, it would be very plausible for you to replace that one only.
In any case, it doesn’t hurt to make sure the other mounts are operating in the same manner since they tend to be around the same age and might be close to reaching their limit. The damaged mount might also place some level of stress on the other mounts, thus leading to a reduced life span.
How a Motor Mount Works (and Types)
Motor mounts are crucial parts that attach your engine to the frame or subframe of your vehicle. Three to four mounts are used in most vehicles for the engine, and additional mounts for the transmission are added.
These mounts serve two primary purposes: to make sure that the engine is secured in position and to limit vehicle vibrations.
The simplest motor mount design has two metal brackets with a cushioning central portion connecting them.
The design above helps restrict contact between the frame of your engine and the body of your vehicle. This enables the reduction of vibration transfer from your engine to your car and the spaces inside the vehicle.
Common Types of Motor Mounts
Conventional Rubber Mounts
Daily drivers benefit from inexpensive and reliable motor mounts made of solid rubber. These mounts offer sufficient cushioning and are therefore the most frequently used type of rubber mounts.
In comparison to other, greater options, simpler solutions tend to incur greater replacement costs and have a greater cabin noise problem.
Hydraulic Mounts
The hydraulic option is an advancement in technology that comes with being able to afford modern vehicles. Most of them come equipped with fluid-filling chambers capable of dampening vibration better than other types of mounts. Because these mounts adapt to engine load and speed, they outperform rubber alternatives.
True, these mounts are on the pricier side, but you’ll appreciate their value in long-lasting comfort, better driving experience, and reduced discomfort.
Active Motor Mounts
Active motor mounts include sensors that adjust to the driving conditions’ stiffness digitally. Although luxury vehicles serve as the primary users of this technology, active mounts improve the overall driving experience.
The cost incurred on the active mounts is substantially higher in comparison to other types, but the performance is unmatched.
Hybrid Mounts
These hybrids offer a middle ground solution by combining features of both rubber and hydraulic designs. They typically use rubber cushioning but incorporate fluid chambers, leading to better control of vibration than conventional rubber mounts while remaining more affordable than fully hydraulic options.
If your motor mounts do not work properly, the vibrations from the engine would be transferred to the frame of the vehicle, leading to damage of various parts and resulting in a very uncomfortable drive.
The engine mounts also prevent the engine from moving up or down during acceleration or deceleration, and even turning, maintaining proper positioning of the belts, hoses, and wires interlinks.
Why Do Motor Mounts Break?
Most motor mounts are made with rubber, so they are bound to succumb to aging at some point. Over time, rubber dries out, breaks down, hardens, and cracks. Rubber may separate from the metal, which then gives the engine the ability to lift and shift.
Generally speaking, motor mounts are quite durable, sometimes even lasting the life of the vehicle.
On the other hand, road damage, leaking fluids, and aggressive driving can weaken them. In any case, it is beneficial to have the mounts inspected regularly, like any other component of your vehicle.
How to Tell if Engine Mounts Need Replacing
Knowing these signs of a damaged or worn engine mount will aid in determining when the mounts need replacing:
#1. Excessive Vibration.
Engine mounts serve the purpose of making certain an engine is accurately secured and preventing any vibrations from being transmitted to other areas of the vehicle. One of the first signs that will provide more tell-tale signs to replace an engine mount will be if you are experiencing greater and or increased vibrations.
The property of an engine mount having some form of vibration-dampening functions is said to be damaged may lead its properties to a decrease. There could be a reduction in the stiffness of rubber, failure of bonds, or even leaked fluid-containing mounts.
In such a case, the engine mounts could be losing effectiveness and could potentially transfer more vibration and noise from the engine to the driver’s cabin and drastically lowering the driver’s comfort levels.
#2. Impact Noises From the Engine Bay.
Hearing the engine section of the vehicle make clunking, banging, or knocking sounds isn’t out of the ordinary and is considered a common occurrence due to the failure of the motor mount.
Noises from the engine part of the vehicle are only expected during the normal operation of the vehicle, like during acceleration, braking, and shifting.
The reason is due to the worn-out mounts that enable excessive movement of the engine, causing the engine to move and bang into the other components. Buffer spaces are purposely built between certain parts of the components within the engine design.
The space movement of the components is designed to have certain limits that are exceeded by poorly functioning motor mounts.
If you start the car or drive on bumpy roads, you might particularly notice these sounds being quite pronounced.
#3. Engine Movement During Start-up and Shutdown.
You may notice your vehicle jerking forward with the sudden application of force when the engine is started, which is a result of torque motor control.
This jerk movement typically results in residual shake motion, also termed vibration. However, there can be a lurch felt upon switch off, which normally is associated with engine shutdown.
This is the consequence of vehicle engine movement due to internal combustion engine torque and its constraining stiffness in terms of the engine mounting system.
#4. RPM-Dependent Vibrations.
The range of speeds of different units of basin engines also results in the creation of different vibration patterns, while the worn-out motor mounts often manifest in the form of vibrations at given RPM ranges.
In this case, vibrations associated with the range of 800-1200 RPM are strong. During acceleration, the 2000-3000 RPM range is more pronounced. As the vehicle moves, these vibrations occur in direct relation to an increase in the engine rotational speed, thereby appearing and disappearing.
Notice whether the changes in the strength of vibrations when the fuel is being continuously supplied to the engine, as the throttle adjustment, are a good indicator of control mounts failing.
#5. Engine Sagging or Tilted.
A third symptom that suggests a problem with motor mounts is an observable ‘sag’ or tilt of the engine to one side. This misalignment might also be visible from the gaps around the hood or fenders, so it doesn’t always have to be in the engine bay.
Besides causing visual displeasure, this off alignment is also harmful due to the strain it places on belts, hoses, and electrical connections.
While inspecting the engine, confirm whether the engine appears level and if the mounting points are at the same height. If any sign is evident of a single side drooping or tilting, paying attention to mount failure, there is a reasonable reason for concern.
This tends to be a progressive issue, getting worse over time. The moment one mount fails, the rest are left with little choice but to bear additional load, triggering a domino effect in no time.
#6. Transmission Shifting Problems.
An unfavorable motor mounts position greatly affects the vehicle’s transmission due to excessive engine movement. A considerable shift in the placement of parts disrupts the precise orientation that should be maintained for effortless engine shifting.
Excessive delay in putting the vehicle in gear, noticeable shift in harshness of engagement or engaging into gear, and a ‘thud’ like sound while changing gears are outcomes of poor motor mounts.
This occurs since the transmission must shift properly, which means it needs to be correctly aligned with the engine and the transmission system.
If these are noticed alongside other issues with engine mounts, shifting difficulties are likely to be attributed to failed motor mounts, and not a problem with the transmission itself.
While other transmission problems may be difficult to diagnose accurately without proper driving and vehicle maneuvering, the answer is far simpler if motor mounts are broken instead — motor mounts are easier to diagnose than severe transmission illness.
#7. Squeaking or Rubber Noises.
A characteristic rubber-on-rubber noise or squeaking can signify broken motor mounts, especially if it’s the rubber kind as opposed to hydraulic.
This noise is more easily heard during acceleration, braking, and shifting between neutral and drive positions.
This occurs because the rubber constituents of the motor mount are in the process of deterioration and have begun to break apart, enabling contact to occur where no contact should be present.
This squeaking becomes progressively louder as the mounts begin to fail. The noise is most prominent in cold climates when the rubber parts are rigid and less pliable, further eroding flexibility in the mounts.
#8. Component Damage in Engine Bay.
If someone has any severe cases of failing motor mounts, observable damage to different components of the engine bay will be noticed. This can also be a result of the second symptom (Impact Noises) mentioned above.
These could involve old or broken radiator hoses, worn belts, overloaded electrical contacts, or signs of contact between the engine and other components. The most common checks include the area around the radiator fan shroud, the belt region, and any point where engine hoses or wires are connected.
Signs of wear that could be broken clips, brackets, or rubbing patterns should be checked as well. Such damages suggest that there has been excessive movement of the engine, and urgent attention is required.
Motor Mount Replacement Cost
The cost of replacing motor mounts greatly differs depending on the make and model of your vehicle, as well as the place where the replacement is performed.
Most of the cost comes from labour because gaining access to the motor mounts often necessitates jacking up the engine and removing other parts of it.
Here is the amount of money you may need:
- Parts Cost – Between $75 and $200, depending on which brand you buy. OEM (Original Equipment Manufacturer) mounts tend to cost more than the aftermarket ones, but their quality and fit are generally more dependable.
- Labour Cost – Because of the complexity of the job, labour costs vary between $300 and $600. Some luxury or hard-to-service vehicles may even exceed this amount because of their design and the increased time required to get to the mounts.
- Total Cost – Anticipate a charge of $375 to $800 for a single motor mount replacement. Typically, mechanics tend to suggest replacement of the mounts in pairs or sets because they are known to wear at approximately the same rate. The entire set of these mounts could be at around $1,000 to $1,600, including the labour charges.
Keep in mind, however, that these prices depend on the location and the repair shop you choose. Dealerships situated in the major city area are usually going to have the highest prices, while independent shops in the suburbs or rural areas tend to have lower prices.
In some cases, if you are unsure which mounts need to be replaced, you may be charged a diagnosis fee. While it may be tempting to go for the cheaper option, avoiding premature failure of parts requires choosing quality ones, which helps eliminate repeated repairs.
Common Causes of Engine Mount Failure
Age and Normal Wear
Motor suspension mounts are subjected to wear and tear with excessive mileage and time. There is the loss of elasticity in rubber parts as well as the development of tears in hydraulic mounts.
Most mounts seem to be functional for a period between 5 to 10 years or between 60k to 120k miles mechanically and under normal conditions. However, this can differ with every vehicle.
Oil Contamination
Oil escaping from the engine can cause degradation to rubber mounts. This is especially the case when the oil is leaking at a slow and steady pace, as it makes the rubber lose its ability to act as a cushion, greatly increasing the rate of decay.
Aggressive Driving
Harsh acceleration, sudden braking, and aggressive cornering create excessive stress on motor mounts. Taking stock mounts over their power limits, due to added engine perks, is another common reason for their early degradation.
Impact Damage
Rough riding on curbs, potholes, or overly bumpy roads can considerably break or damage motor mounts. This action mostly causes impact to the metal brackets of the mount and not so much on the rubber parts. Cracks brought about by my minor impacts have the potential to worsen with time.
Environmental Factors
Mounts in regions where temperatures are extreme alongside road salt are likely to lose mounts at a faster rate. While cold weather can make certain materials prone to cracking, heat does bring about deformation. In general, harmful components such as road salt can weaken the strength of metal parts.
Can I Drive with a Bad Motor Mount?
While your vehicle may still operate, it is strongly advised not to drive a vehicle with a damaged motor mount. A bad motor mount can set off a chain reaction of mounting problems.
In this case, excessive engine movement will stress any remaining good mounts and damage important parts such as belts, hoses, and the wiring harness.
In extreme cases, completely broken mounts could allow an engine to shift about wildly with braking and acceleration. This could lead to significant damage to the vehicle or lead to the driver losing control of it.
If the vehicle needs to be driven to a repair shop, the best course of action is to maintain moderate speeds, adopting a smooth driving style with the gas and brake pedals, and taking the shortest and safest route to get to the repair shop. But a prompt repair would be required before the underlying problems manifest more serious complications (and costs).