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Replacement Mounts – When And Why You Need To Replace Your Engine Mounts

An engine mount’s primary purpose is to secure an engine to its anchor point while absorbing shocks and vibrations when in operation, making anti-vibration mounting systems essential for preventing damage to the engine and improving performance. Over time, replacement mounts will need to be installed to prevent damage to the engine and to ensure ongoing user comfort. Understanding when your mounting systems need replacing is key to having a smooth engine experience. Below, we outline some key symptoms of damaged engine mounts and what happens if damaged engine mounts go unchanged, along with a few other frequently asked questions in regards to engine mounting systems.

How To Tell When Your Engine Mounts Need Replacing

Being aware of common symptoms of damaged or worn engine mounts will help you identify if and when replacement mounts are on the agenda:

  1. Increased Vibrations:

One of the most common symptoms of damaged or worn engine mounts is increased vibration during operation. If you notice that your engine is making more noise, or you feel more vibration than usual when started, this is a key sign of worn mounting systems that may need to be replaced. When engine mounts are damaged or worn the anti-vibration properties weaken as the mount can no longer perform at 100%. An increase in vibration leads to the engine making more noise, causing damage if left for an extended period.

  1. Rough Start:

Upon starting your engine, you may notice an excessive lurch that doesn’t feel right. This is another common symptom of damaged engine mounts. When running it may steady into a constant vibration, another telltale sign. You may also experience a lurch when turning the engine off.

  1. A Rough Ride:

Another common sign that replacement mounts are due as a result of damage is a jolt caused when changing gears. It is also noticeable when the engine is working harder under load. If your engine doesn’t have the same smooth feeling, a worn engine mount could be the cause.

  1. Excessive Noise:

Excessive noise coming from the engine is a by-product of failed mounting systems due to the increased movement causing the engine to become misaligned and make contact with other components. This can lead to impact sounds that become quite noticeable.

  1. Visual Wear:

With use, engine mounting systems do change in appearance. However, if significant corrosion, cracks, or crumbling are seen, the mounts will likely be worn. If any cracks or crumbling to the engine mounts properties are noticed, this will limit its performance dependant on the severity and root cause. The effectiveness of mounting systems relies on their form and shape, as any changes can damage the engine. If you notice any visual wear of the engine mounts, replacement mounts should be top of the agenda.

What Causes Damaged/Worn Engine Mounts?

There are many reasons as to why engine mounting system’s may be damaged or worn. Below are some of the most common:

  1. Poor Installation:

While you can install your engine mounts yourself, it is always recommended to get a reputable and qualified mechanic to either install the mounting systems or check the final installation and adjust where needed. This will ensure that your new engine mounts will be installed properly to perform as they should and last longer.

  1. Ageing:

A common cause for engine mount failure is age. The materials used to make engine mounts are prone to wear over time and may lose anti-vibration properties, lessening the function to your engine. Age and stress can lead to the engine mounts breaking down. As soon as this is noticed, made obvious by more vibration and excessive noise, you should seek replacement mounts.

  1. Accident Involvement:

If you have experienced an accident, you should always check for internal damage, such as engine mount failure. The jolt of an accident can cause mounting systems to become damaged which will worsen over time leading to increased vibration and excessive noise.

  1. Operation Techniques:

Excessive operation, including over-revving and improper use of gear change, can cause severe damage to your mounting systems. Practising proper operation techniques can extend the life of your engine mounts significantly.

  1. Fluid Leaks:

Especially in rubber mounting systems, fluid leaks could cause the material to soften, leading to failure.

What Happens If Damaged Engine Mounts Go Unchanged?

No matter the quality of your engine mounts, they will begin to wear over time due to the factors above and eventually will require replacement. Not replacing an engine mount that is worn out can lead to the following:

  1. Engine Damage:

Excessive engine movement may occur due to failed engine mounts causing misalignment. Damaged or worn mounting systems may cause the engine to slide around in all directions, which can be particularly noticeable when working hard under load.

  1. Risk:

If an engine mount breaks under load, it will no longer be effective in supporting the engine. Damaged components can create a safety hazard for yourself and others around.

How Long Do Engine Mounts Last?

Usually, engine mounting systems tend to last at least 5-7 years, depending on the application. However, it is always recommended to get them checked regularly when maintenance work is conducted. Making sure your mounting systems are maintained and alignment is obtained will keep your operating experience as smooth as possible.

Should I Replace All Engine Mounts At Once?

While replacing all mounting systems at once isn’t needed, it is always recommended. When one engine mount is damaged more pressure is put on the remaining, causing them to work harder and accelerate the wear. If you only replace one engine mount it is recommended you pay close attention to the others as the accelerated wear could cause failure soon after. Therefore, you may have to change more than one mounting system, if not all, depending on how much damage has been caused. As such, it is recommended all replacement mounts should be installed at the same time. 

Why Should You Use Poly Flex Engine Mounts?

Poly Flex engine mounts are a high quality, high performance, durable and robust true marine propulsion mounting system designed with sufficient vertical deflection to obtain proven vibration isolation with minimum thrust and lateral deflection under load and inertia due to conditions.

Made from a high quality engineering grade polyurethane, these mounts prevent rust and are resistant to oil and fuel. They are designed to isolate vibration across the rev range without compromising the alignment of the driveline. Designed as a fail-safe system that is capable of holding the same weight inverted to avoid the engine tearing away from its anchor point in rough conditions or the event of a capsize.

Poly Flex mounting systems allow for easy replacement of the core and hardware, limiting the need to replace the whole unit. They control thrust in all directions due to the core design being 360 degrees and can handle shock upon impact due to a 400% stretch factor in the polyurethane base material. All the metal components are coated in SA5 Cobalt Zinc inhibiting rust for extended life and due to the polyurethane design no electrolysis occurs between aluminium and steel structures.

All Poly Flex engine mounts are Det Norske Veritas (DNV) type approved for vessels in survey. Poly Flex have been providing Australian made quality and performance that is second to none since 1981 and with a strong focus on customer service hope to continue for many more years to come.

For more information regarding Poly Flex Mounting Systems click here, including our Core Replacement and Engine Mount Assembly Procedure. For enquires regarding replacement mounts contact us today.