Hydraulic engine support. Engine mounts: signs and causes of malfunction

30.07.2019

Timely prevention is the key long service vehicle and safety during its operation. For this reason, it is advisable for every driver to monitor his car on his own. For the integrated implementation of planned operations, knowing how to check the health of the engine mounts will not be superfluous at all.

Read in this article

Types and types of engine mounts

Before checking anything, it is also necessary to understand the purpose of the part, what malfunctions of the element may occur, and also what signs a breakdown has. As you know, the engine weighs a lot and vibrates during operation. This means that if rigidly attached to the car body, then all vibrations will be transmitted to the latter.

While driving over uneven places, the attachment points of the power unit experience significant loads. Rigid attachment to the body will mean that the fasteners and their installation site will begin to break quickly. To general design was reliable and comfort was maintained; special supports are used to mount the internal combustion engine.

Pillow (engine support) - a part that serves to fix the power unit, prevents its displacement and dampens vibrations during operation. At its core, this is a real gasket, only quite big size. It is placed between the engine and the body of the car, that is, it is attached both to the power unit and to the body itself. The number of pillows depends on the make and model of the car, there are from three to five.

If you open the hood, you can immediately see the top (right support). The rest are on the underside of the motor. Again, the placement points depend on the car model, engine type and transmission. In most cases, engine mounts consist of a rubber housing and metal fasteners.

Sometimes polyurethane is used instead of rubber, which is more wear resistant. IN expensive cars more complex and modern options– hydraulic. Vibration damping efficiency is naturally much higher.

Such supports consist of two chambers, between which the membrane is located. The chambers are filled with either propylene glycol or special liquid(gel). During operation, depending on road conditions(for example, on bumps), it flows from one chamber to another through special channels, and the overall stiffness of the pillow changes dynamically due to this design.

Hydro supports are different:

WITH electronic control. The computer changes the rigidity of the support by receiving and processing signals - vibrations, the strength of which varies depending on the situation. The liquid inside such a cushion often contains metal particles and the density changes under the influence of magnetic field. Thanks to these technologies, it is possible to achieve maximum comfort in the car, regardless of the engine operating mode and road conditions;
WITH mechanical control. An easier option. Specifications set at the build stage. It depends on them in which mode the maximum benefit will be: on Idling or at different modes motor work.

Of course, high-tech devices are installed on very expensive cars. On budget options, and even more so on the old Soviet models, simple rubber-metal supports are installed. In case of breakage or wear (usually they can withstand about 100,000 km), they are simply changed. And the hydraulics can be repaired. And even on their own. However, before removing the mounts, you need to know how to check the engine gel pad, rubber, etc.

Signs and causes of engine mount problems

The main signs of malfunctioning pillows (supports) of the engine are:

strong vibration on the steering wheel when the engine is running;
knocking in the area of \u200b\u200binstallation of the gearbox while driving over bumps;
while driving and shifting gears at high speed;
knocking under the hood while overcoming rough roads, as well as at idle and when the load changes while the engine is running;

When these signs appear, it is worth diagnosing the pillows. You can do it yourself.

Do-it-yourself engine mount check

It is not at all difficult to make such a diagnosis. Even if hydraulic cushions are used on the car. The main thing is to know how to check the right engine mount correctly, as well as diagnose the rest. This can be done in several ways, which are best used in conjunction with each other to make a more accurate diagnosis.

The first method is good for hydraulic supports. Having installed the car on a flat surface, you need to open the hood and start the engine. Then try to move a little.

With faulty pillows, the engine will move from its place. At the same time, characteristic sounds will be heard well. A similar check can be done on an idle motor, if you insert a pry bar or stick between the motor and the car body and try to shake power unit from side to side.

The second way to check is this. With the engine running, you need to turn on the gear and move off a few centimeters. On different types Checkpoint with malfunctions of the pillows, characteristic jerks can be felt.

To check the lower supports, you will need an inspection hole, a jack and a wooden deck about half a meter high. Raising one wheel and replacing the jack with a deck, you need to inspect the bottom of the pillow for cracks, tears, drips hydraulic fluid. Of course, before this, it is necessary to take security measures, eliminating the shift of the car from its place (anti-rollback block under rear wheel and so on).

In order for the supports to last as long as possible, you need to monitor your driving style. The principle of "higher speed - fewer holes" must be thrown out of your head forever. In addition, the engine mounts are more likely to fail if you start off frequently and abruptly. In a word, the less sharp fluctuations of the internal combustion engine, the less often it will be necessary to check the health of the engine mounts.

Symptoms

When, when crossing obstacles in the area of \u200b\u200bthe gearbox, a characteristic knock is observed that violates sound insulation in the cabin, most likely, attention should be paid to replacing the engine mount. In addition, a defect in such a gasket is indicated by strong vibration transmitted to the housing. passenger car. If a running motor starts to knock on the frame, then it is necessary urgent replacement engine mounts.

You should pay attention to the condition of the pillows when, during braking and at the beginning of the movement of the car, clicks and other extraneous sounds front. It should cause concern if a roar occurs in the cabin when overcoming holes and potholes on the road. If driving over rough terrain is accompanied by a kickback on the gearshift lever, the support must be replaced immediately.

And also evidence of signs of malfunction of the engine mounts is a significant increase in the level of vibration when starting or turning off the mechanism. Ignoring such symptoms is strongly discouraged. The consequences can be very unpleasant, ultimately expressed in the deformation of the suspension and body, premature wear transmission.

Therefore, if the car shows signs of a malfunction of the engine mounts, then the failed gaskets must be replaced.

Suspension self-diagnosis

If it is impossible or unwilling to visit a car service, it is possible to manually determine the malfunction. Self check the condition of the engine mounts is performed using the following tools:

hydraulic or pneumatic jack. This device facilitates access to the checked pillows;
special safety support. In this capacity, a wooden block is most often used;
a mount or a sufficiently strong stick that acts as a lever.

the car is driven into a garage or other room. Necessary condition a flat floor surface is considered;
Jack under the front wheel to raise the car. For rear wheel drive cars lifting device located under the rear wheel;
the support is installed under the motor so as to ensure that there is no load on the motor mounts. After making sure that the car is stable, the jack is lowered.

Using a tackle, they are arranged under the car and conduct a visual inspection. This method of inspection makes it easy to examine the engine mounts for signs of malfunction acquired by the engine mounts during operation.

Even an inexperienced motorist is able to see the symptoms of delamination of the support, cracks and tears on the product, and also independently determine that the gasket has failed as a result of excessive hardening of the rubber. In such cases, it is strongly recommended to urgently replace the engine mount.

To detect possible play at the junction of the motor with the front beam of the machine or the body visual inspection not enough. Here you will need to use a mount. A similar lever is used to deflect the engine in different sides. The absence of backlash indicates the serviceability of the supports; repair of the pillows is not required.

You can eliminate this symptom as follows:

raise the car again with a jack;
remove the safety support;
check the quality of fixation of the engine mount and, if necessary, tighten the fastening with a wrench or ratchet.

In this way, they get rid of backlash.

Self-replacement of engine mounts

In order to keep your car in perfect order, you need to regularly check technical condition. Since the failure of one part can disable the entire expensive unit, it is necessary to replace the faulty mechanism in a timely manner.

We are offering to you detailed instructions how to change unusable engine mounts with your own hands:

having de-energized the battery by removing the terminals, the car is raised to a sufficient height to provide comfortable access to the motor. After applying the jack, the car is securely fixed with wooden blocks;
using the same lifting device, raise the motor, releasing the required part from the load;
the engine mounts are fastened with a certain number of bolts, which must be removed after unwinding;
after removing the defective part, new spare part installed on appropriate place. Fasteners in the form of bolts securely fix the engine hydraulic support. It should be noted that a running motor while tightening the fasteners will protect the car from subsequent excessive vibration;
the completion of the installation of the engine support cushion is accompanied by the return to their proper places of all dismantled parts.

Separately, we note that all the proposed manipulations are recommended to be performed in tandem with an assistant. Outside participation will be required to guide the lever of the engine during the installation of the support in the required place.

Inspection and replacement of the top cushion is sufficient simple process. The accessibility of manipulations is provided by the ability to do without a pit. In addition, it is not necessary to lift the car.

Conclusion

Regularly checking the condition of the engine mounts helps prevent many problems in the long run. Timely replacement unusable support provides a comfortable stay of passengers in the passenger car.

If you are concerned about the health of all components and systems of the machine, it is recommended to periodically check the pillows. As the previous study showed, all the necessary manipulations can be performed independently, without the help of car service specialists.

Perhaps the most popular support for the power unit in a car has long been considered rubber cushions. Rubber provides a vibrating engine with relative freedom of movement and thus dampens vibrations well. The most important disadvantage rubber mounts - they do not interfere, and sometimes even contribute to the emergence of resonance, as a result of which the body begins to vibrate even more. Rubber cushions are inferior to other types of supports in terms of wear resistance.

Hydraulic bearings contain a fluid that performs the same function as rubber - provides mobility to the power unit. Fluid is more dynamic than rubber. It absorbs engine vibrations faster, leaving less chance for resonance to occur.

How the ACM works: The active engine mount uses the vacuum in the intake manifold as an energy source to create oscillations in antiphase of the engine vibration.

The first publication on the idea of active vibration suppression appeared in the Journal of the International automotive engineers SAE in 1986. Mitsubishi engineers reported that during the experiment they were able to reduce the vibration level at the driver's seat by 16 dB. As a conclusion, they predicted the imminent incarnation similar system on stock cars.

We had to wait quite a long time. Only since 1998, the serial Lexus began to flaunt the active supports of the power unit, using the vacuum in the intake manifold as an energy source. Competitors were not long in coming: in the same year, diesel Nissans were released, in the 2000s Honda appeared with a similar system.

From a technological point of view (permanent four-wheel drive without forced blocking and downshift) Highlander is an urban crossover. But in terms of dimensions, it will give odds to many SUVs. With dimensions of 4785 x 1910 x 1760 mm, a boot volume of 290 liters or 2305 liters with the third row of seats folded down is offered.

Air or current

On modern Toyota Highlander uses an active engine mount (ACM, Active Control Mount) at the front in combination with passive hydraulic cushions behind. As can be seen in the diagram, the active bearing also contains a hydraulic fluid chamber and acts as a hydraulic cushion. The difference is that the bottom of this chamber is the diaphragm. On the other side of it is an air chamber connected to vacuum system through an electronically controlled valve.

Thanks to the valve, the air chamber communicates in turn with intake manifold, then with atmospheric air. This causes the diaphragm to oscillate, changing the pressure of the hydraulic fluid in the mount. The valve is controlled by a computer based on the readings of the crankshaft position sensor. Thus, the support vibrates exactly in antiphase with the vibration of the engine itself and dampens its vibrations. The system only works at idle. In motion, when the engine is already stable due to increased speed, the valve closes and the active support turns into a conventional hydraulic cushion.

There are similar ACM systems that are structurally different from Toyota vacuum mounts. In 2003 year Honda introduced the Variable Cylinder Management (VCM) engine. Its essence lies in the ability to turn off part of the cylinders when maximum power not required. So, a 6-cylinder engine on the highway can become 4- or 3-cylinder, blocking the fuel supply to the corresponding combustion chambers.

The introduction of VCM has made active engine mounts a necessity: a motor that is designed as a 6-cylinder has a hard time maintaining balance when halved. The moment of switching between standard and economical modes can be especially sensitive.

Honda's ACMs are ordinary hydraulic supports, to the chambers of which hydraulic lines are connected. Each line leads to a solenoid that increases or decreases the pressure in the chamber at the command of the processor. Dignity Honda systems- in its colossal flexibility: according to the task, it can work at any engine speed. Main disadvantage lies in the fact that the solenoid consumes electricity, while the vacuum in Toyota system can be considered free.

The car engine is heavy enough and subject to vibrations, so it must be secured from any displacement during operation. If the fastening points are rigidly connected to the body elements, then they will fail very quickly, since when driving along the unevenness of the roadway, the fastening points will perceive significant alternating loads.

Plus, the entire body will constantly vibrate, which, in addition to discomfort for those inside the car, will also negatively affect the durability of all elements of the car.

Pillow (support) of the VAZ engine

Purpose

Special supports or, as they are also called, pillows serve to dampen vibrations during engine operation and to securely fix it.

The support is not called a pillow by chance, as it fully corresponds to its purpose. So in explanatory dictionary Ozhegov, one of the meanings of the word “pillow” is that which is the support of something, takes on the pressure of the mechanism.

The main objective of the installation of supports is the reliability of fastening and minimizing the displacement to the sides during operation.

In addition, thanks to the pillows, the power unit is isolated from all body parts, which makes the car comfortable to drive.

Depending on the model of the car, the engine can have from 3 to 5 pillows.

So the front and rear airbags monitor vibration at idle and when the engine is at maximum load.

Design

The simplest support is a rubber-metal element, where a layer of rubber is placed between two steel plates. The plates have a threaded part in the form of a stud at the ends for connection with body parts. Such products can be made both solid and collapsible.

Some supports, such as classic models vaz 2101-07 inside the pillow also had a spring and a rubber bumper, which increased rigidity and softened strong blows.

Recently, instead of rubber, manufacturers have increasingly begun to use polyurethane, as the most wear-resistant, and metal in most cases has given way to aluminum.

For more expensive models cars for greater driving comfort are used more modern designs such as hydraulic supports. They consist of two chambers and a membrane between them, the chambers are filled with liquid, which, when loaded, can move from one container to another.

Such supports can be adjusted to the operation of the power unit in any mode of its operation and are able to dampen any vibrations as much as possible, significantly increasing the degree of comfort when operating a car.

The greatest loads on the engine mounts occur when it is started, started and stopped. vehicle. A failed mount puts more stress on the engine and transmission, making them more likely to fail.

Faults:

Cracks, breaks on the body of the filler, or steel plates;

Pillow deformation;

Detachment of rubber from metal;

Symptoms of a malfunction:

The motor "jumps" when starting and braking the car;

Impact when planing at reverse speed;

When driving on a rough road, knocks are heard, similar to a malfunction of the chassis.

Causes of the malfunction

There can be several reasons for premature airbag failure. So, for example, when tuning a car, shock absorbers with a more rigid characteristic are installed, low profile tires to improve manageability and change appearance auto. However, in this situation, the shock absorbers on the pits do not completely dampen body vibrations, which have a negative effect on all elements, including engine mounts.

Driving style. These are sharp starts and braking provoking huge loads on the engine mounts due to the rapid shift in the center of gravity. This should also include the passage of bumps on the road without reducing speed.

Natural wear. These are mechanical loads, temperature changes, aging of the rubber filler, which loses its elasticity.

Replacement terms

Average support power plant able to go about 100 thousand kilometers or more (up to 200 thousand) with moderate driving and proper monitoring of their condition.

If any signs of malfunction of the engine and gearbox mountings are found, it is recommended that they be replaced without delay. In this case, you should not purchase products from an unknown manufacturer, giving preference to the original.

Finally. Serviceable supports are comfort and safety of movement, as well as extending the life of your power unit.

For a car to move, it needs an engine. This unit is installed in the front of the body (in most cases). It is mounted on a subframe or on the spars. However, the vibrations that the engine gives off during operation are strongly given to the body. To smooth them out, it is installed with rubber pads. They are a kind of buffer. In time everything Rubber products are falling into disrepair. The engine mounts are no exception. What is and methods of elimination - further in our article.

Characteristic

What is this detail? An engine mount is a gasket between the bodywork and the power unit. This is installed on all cars without exception. On the Soviet Zhiguli, the pillow was a durable piece of rubber with fasteners on both sides. On more modern “nines” and “eights” (and later on all VAZs with a front-wheel drive layout), full-fledged rubber-metal supports were already installed.

So, the power unit was mounted on four pillows. Two of them are on the gearbox, and the rest are on the engine. In order to avoid unnecessary loads, the box with the motor is rigidly fixed. Any distortion leads to a change in geometry input shaft. As a result, all vibration is strongly transmitted to the gearbox lever and the transmission itself.

Where are the pillows? On the engine given element installed from multiple angles:

Front cushion. It is attached to the front beam of the power unit.
Back cushion. Installed to front subframe. Located in the bottom area.
Right support. It is located on top, at the front side member of the body.

Also note that the rear support is not on all cars. This function is performed by itself.

In this case, it is closely attached to the motor. The pillows themselves are made in different shapes. Often they are an aluminum or steel cylinder with a silent block inside. For fixing on the body, the so-called "paw" is used. It also has a rubber spacer. This is how modern engine mounts are designed. Symptoms, how to diagnose a part that affects wear - we will consider in the course of this article.

Why does it wear out?

Many motorists ask this question. Signs of a bad engine mount can vary. This is primarily due to natural wear and tear which is due to vibrations. The resource of these elements is about 150 thousand kilometers. How stronger vibration, topics more load on a support (especially if one of the cylinders does not work in the engine).

If you think that the resource directly depends on the mileage, you are mistaken. The cushion wears out even when the car is in the garage. Over time, the rubber will dry out. Microcracks appear. Another negative factor is oil. It is necessary to change the seals in time in order to eliminate smudges.

Oil negatively affects the life of the engine mount. Symptoms of a VAZ 2110 malfunction may also lie in the driving style. Yes, at abrupt start with slipping, an enormous load is placed on the support.

How to quickly determine the malfunction of the engine mount?

You can determine the health of the element without opening the hood.

While driving you will notice characteristics engine mount faults:

There are characteristic knocks and clicks when starting and braking the car (in the front).
When driving on rough roads, strong shocks are transmitted to the body.
At idle there is excessive vibration.
Blows are given on when driving (especially when the car goes through the pits).
Strong vibration of the steering wheel at all engine operating modes.

We determine the condition of the supports visually

Not always the above signs will indicate a malfunction of the engine mounts. So, if impacts are observed in the front of the body, you need to visually inspect the element. Where it is, we already know. So, open the hood and look at the state of the rubber buffer.

It should not have breaks or cracks. For better convenience, it is recommended to use viewing hole(especially if it is a front and rear support). Move it from side to side. There should be no play between the cylinder and the silent block. If so, the signs of engine mount failure are confirmed. The part is to be replaced.

How to change with your own hands?

To do this, you will need a set of tools (heads and open-end wrenches), a jack and repair stands (since the engine will be “on weight”). So let's jack up the car right side. We hang the motor on the chain. We unscrew the bolts (there are 3 in total) that secure the support to the engine and body. Next, remove the brackets and take the element out. Install new part into place.

To replace the rear support, jack up the body on the left side. However, unlike the previous case, we will have to hang the gearbox as well. We use a wooden substrate so as not to damage the pallet. We unscrew the bolts of the pillow and get it out. We install a new one in place of the old one and assemble in the reverse order.

Motorists recommend replacing the support in warm weather. In winter, the pillow becomes very “dubbed”, and it can be removed only after preheating (this is a hair dryer or a blowtorch). If the support does not come out, it is recommended to use a VD-40 type lubricant or its equivalent from the Mannol manufacturer. Conventional lubrication not suitable for this.

Often, dust and moisture get into the cavity of the old pillow, as a result of which corrosion processes occur on the cylinder. It is not possible to remove the pillow. If you are changing back support, observe the direction indicated by the arrow on the part. It must be installed in the direction of the vehicle. Otherwise, there is a risk that the element will not withstand the loads and break.

Conclusion

So, we found out the main signs of a malfunctioning engine mounts. An internal combustion engine support is a very important part in a car. Therefore, you need to know how to identify its malfunction and how to change the part to a new one. We hope this article has helped you resolve this issue.