Hydraulic cushions. engine mounts

30.07.2019

Miscellaneous

Comfort in the car interior largely depends not only on properly made high-quality noise and vibration isolation. Even if there is such discomfort, it can still occur. Often motorists are faced with engine vibrations. They can occur due to malfunctions in the engine or as a result of breakdowns in the motor fasteners. Especially often, owners of cars from Avtovaz, where sixteen-valve power units are installed, complain about these problems. Car owners are faced with a strange knock in the engine compartment. He is fickle. It may appear, then disappear during acceleration or when driving along flat road. The reason for this is a malfunction of the engine mount. Signs of this phenomenon are vibrations. But that is not all.

Common Causes of Engine Noises

If in the process of driving a car, a characteristic knock from under the hood, more precisely, from under the lower part of the engine or in the transmission area, became clearly audible, if noise and vibration increase during the shift from 2nd to 4th gear, then this may be associated with violations in the operation of the suspension or with the operation of the engine. Depending on the state pavement these sounds may increase.

Engine mount

A pillow is a gasket between the engine and body elements. On cars Soviet-made this product looked very simple. This is a durable rubber insert with places for fasteners. The modern support of the power unit can be in various designs. Allocate hydraulic cushions, rubber parts. Often, the engine and gearbox on front-wheel drive vehicles are secured using four or five of these supports. So, two of them are under and the rest are under the motor. The rubber-metal support may look different.

A cylinder made of steel or aluminum, inside which there is a rubber silent block. There is also a so-called lamp made of aluminum alloys with a rubber insert.

Standard cushion arrangement

The right support is located on top and is attached to the side member of the car body. The front one is most often fixed on the motor beam, you can see it from below.

The rear cushion can be found fixed on the bottom or on the front subframe of the body. As for the rear support, then on certain engines it may not be at all. The support for comes as a common. It is installed closer to the rear side of the motor.

Typical malfunctions

If the car is operated for a long time under conditions of serious loads or temperature changes, then all this does not have the best effect on the condition of the engine mounts. Over time, rubber loses its elasticity. In addition, the pillow can delaminate or crack, or even completely collapse. But it is worth considering that the service life of these parts is quite large - more than 100,000 km. The supports are subjected to a high load at the moment of starting the car and during braking. If the car owner likes to drive fast enough, with in sharp jerks at the start, then the supports will not serve their specified period. Also among typical faults you can highlight the breakdown of the metal aluminum bracket. This often happens when driving over obstacles. If oil leaks are observed in the engine, then it will definitely fall on the rubber part of the support. This lubricant can corrode the silent block, and the support will fail. Also, the coolant does not affect the rubber part of the pillow in the best way. Breakdowns in the system must be eliminated immediately.

Not In addition to the cracked cylinder head, there is also antifreeze from expansion tank gets on rubber parts. This will not affect their resource in the best way. It is important to remember that operating cars with broken supports is not only unpleasant, but in some cases unsafe.

How to determine that the support of the unit is out of order

Often, novice drivers do not know how to diagnose an engine mount failure. Signs of such a breakdown are often confused with something else. The first signal of a support failure is unpleasant sounds like clicks or knocks in the front of the car at the beginning of the movement or when braking. Another sign comes to light when driving on rough roads. Such a ride is necessarily accompanied by characteristic bumps in the front of the car. Also, a sudden vibration can indicate a malfunction of the pillow. Sometimes when driving bad roads can give to the gearshift lever. This all suggests that there is a malfunction of the engine mount. These signs must be taken into account and then diagnostics should be performed. Sometimes it is very difficult to determine the breakdown of the support. Usually, motorists attribute vibrations to the fact that the engine is not warm enough and often they simply do not pay due attention to them. characteristic feature, which will tell about the failure of the part - a creak.

Diagnostic methods

So, the owner believes that the engine mount has failed. Malfunction symptoms are confirmed.

Next, you need to check the condition of the supports. In order to verify the integrity of these parts, you will need a jack and any supports - wood stumps, pallets, tires. Anything will do. It is also advisable to prepare a mount or a thick stick. Let's look at how to determine the malfunction of the engine mount. To do this, it is recommended to install the car on the most even surface. Then the car must be raised with a jack, then a prepared support should be installed under the engine. It could be a log or something. It is better to remove the jack.

visual inspection

You can check the condition of the power unit supports visually. To do this, the owner must lie under the car and inspect the supports. On examination, it is possible to reveal hardened rubber, cracks and gusts, delamination - this is actually the separation of metal from rubber.

Backlash check

This option is used if everything is there, but visually something could not be found. It is necessary to check the presence of backlash on the fastening of the engine mounts to the body.

For a full inspection, experts recommend using a stick or a mount to shake the pillows from side to side. If it was possible to find big backlash in places where the engine mount is attached to the body, then you can perform self repair. But you can also go to the service station and fix the problem there.

Signs of failure of the engine mount "Lada Priory"

VAZ cars practically do not differ structurally from cars of any other manufacturers. The same applies to the arrangement and location of parts such as engine mounts. Symptoms of a malfunction (Priora included) can be identified by characteristic vibrations of the motor. This is manifested at idle and at more high revs. The engine will twitch unnaturally.

This is a signal to the owner to check the supports or replace them. The second symptom is steering wheel twitching. The vibrations of the steering wheel depend on the frequency of the power unit. The gearbox can also tell about failed pillows. When moving, gears will be knocked out.

"Ford"

Vibrations on the car body idling and in the process of movement they say that the engine mounts are out of order or damaged. Symptoms of a malfunction ("Ford Focus 2" including) may be different. On Ford Focus vehicles, two supports are used. Right - hydraulic, left - gearbox support. In case of damage, it is recommended to replace both elements.

Naturally, you can only replace the damaged one and the vibrations will pass, however, the new support will be subjected to significantly heavy loads and will fail much earlier than its time. Buy as a replacement original parts. Inexpensive analogues serve less than 20 thousand kilometers.

"Mazda Demio"

Signs of a malfunction of the left engine mount of the Mazda Demio are knocks and vibrations. The supports are heavily loaded. It is worth carefully monitoring the condition of the pillows, a faulty part can damage the motor. There are three pillows in this car: left, right and bottom. The second is located near the oil filler neck of the motor. Under the battery is the left support. The lower one is directly opposite the junction of the engine and automatic transmission. Methods for diagnosing a malfunction in this case the same as for any other cars - these are visual inspection and backlash check.

and automatic transmission

Novice car owners often wonder why the automatic transmission twitches when driving. There are many reasons for this. Can an automatic transmission jump due to a malfunction of the engine mounts? Yes maybe. Sometimes the behavior of the car changes. So if you see extraneous vibrations, shocks, hum, characteristic noise, it is best to check the supports.

Ride comfort largely depends not only on the quality of the suspension, but also on good sound insulation. But over time, they can penetrate into the salon extraneous knocks and vibration. Usually this is due to the silent blocks of the suspension arms. But today we will talk about another rubber-metal element. It's called a pillow. What is an engine mount and what are its signs of failure? We will talk about this in our today's article.

Characteristic

What is this element? The rear and front engine mounts are a rubber-metal product - a silent block with fastening elements. It is also called the support of the internal combustion engine. Both - front and rear - engine mounts perform a single function - damping vibrations that are produced by the engine.

The motor is constantly running under load. And even on idle vibration inevitable. To level them, silent blocks are provided. Through them, the motor is connected to the body. Front and rear support reduces vibration of the engine at idle and in the mode of increased loads.

Types, location

The part is attached in several places. On engine goes two supports - right and front. Also, one pillow can be placed at the checkpoint. But another scheme can be applied:

The right pillow is located on the side member of the car body and is attached from above.
The front support is fixed to the engine beam. Located below.
The rear cushion is located on the bottom or attached to front subframe(if any). Also located below.

The support itself can be aluminum or steel. The latter option is often used for Not expensive cars. But no matter what type and number of them, the failure of at least one of the supports entails irreversible consequences. Next, we will look at the main signs of a malfunctioning engine mount.

How to determine a breakdown?

Finding this out is easy enough. Since the main purpose of the support is to dampen vibrations, such a car will immediately begin to emit increased vibrations. They will be transmitted not only to the steering wheel, but also spread throughout the body. And not only at idle, but also at increased speed(although the nature of the vibrations will change). Also, the blows will be felt on the wings. When starting from a standstill and hard braking you will hear characteristic clicks or knocks in the front of the car. When driving on a rough road, bumps similar to suspension failure will occur.

Thus, the main signs of an engine mount failure are vibration, which makes driving a car uncomfortable.

Causes

Why is this happening? There are several reasons why the front and rear engine mounts fail:

foreign fluids

This is another factor that affects the resource of the support. But few people mention him. Earlier we talked about such a thing as "engine wash". So, it is this operation that can significantly extend the life of the support.

The point is that at long-term operation, the motor begins to be covered with oil streaks. They settle everywhere - on the ignition elements, the cylinder block, the gearbox and, of course, on the pillows. As you know, oil and rubber are incompatible concepts. When lubricant gets on the surface of the support, the latter begins to lose elasticity. As a result, the resource of the silent block is significantly reduced. The same applies to other liquids - antifreeze, brakes, gasoline. Their hit on the surface of the support is highly undesirable. By producing regular washing engine, you can not only extend the life of the support, but also diagnose its malfunction in time, as well as other elements and attachments.

How to replace? Cooking Tools

The only way out with increased vibrations is to install a new support. It has not been repaired and is completely changed. To do this, you need the following set of tools:

A set of sockets and spanners.
New pillows.
Lubrication "liquid key".

Work is best done on a pit or lift. In the absence of such, we use a jack and stops.

Getting Started

So, we hang out the front part of the body and put a safety bar under the motor (since the unit will hang almost in the air). Slightly lower the body so that the motor lies on the bar. We unscrew the fasteners that go to the spar.

Next, remove the bolts securing the support to the frame. It is better to sign them so as not to experience problems with the installation. Next, remove the old pillows and install new ones in the same way. No pullers or special tools are required. However, the diameter bolted connections may differ depending on the type and brand of vehicle.

When installing new bearings, apply a light coat of sealant to the threads. This will prevent unauthorized loosening of bolts during operation and protect the threads from dirt and corrosion. It is recommended to change the supports as a set, so as not to repeat repairs in soon. Also keep an eye on the tightening torque. On VAZ cars of the "tenth" family, the front and right support are tightened with a force of 54-70 Nm. Additional rear - 90-120 Nm. On this, the procedure for replacing pillows can be considered completed and proceed to daily operation.

Any engine vibrates during operation. This is because, depending on , the design of the engine can be balanced to a greater or lesser extent, but it is almost impossible to achieve complete balance. Noise and vibration are transmitted to the passenger compartment and to the car body and cause a feeling of discomfort to the driver.

To combat this phenomenon, an engine suspension system was invented. Its key parts are the bearings, which are often called engine mounts. The support is a buffer installed at the attachment points between the engine and the frame, subframe or car body. They absorb engine vibrations and keep it relatively static. The engine, in turn, is protected from sharp shocks and shocks.

The history of the invention of engine mounts

For the first time, Walter Chrysler, the founder of . He entrusted this task to the lead engineer Frederick Zeder, who put forward a proposal to install a rubber gasket between the engine and the frame. This concept was implemented in the satellite brand Plymouth, which was part of the Walter Chrysler group of companies.

Places for installation of supports

The number of reference points depends on the calculations of the team of engineers of a particular manufacturer, so there can be four, five or more supports. The main criterion for choosing points is the reliability of fastening and the low probability of engine displacement to the side. Most often, the engine, assembled into a common unit with a gearbox, is mounted at three or four points at the bottom and at two or three at the top.

Types of supports, their advantages and disadvantages

IN modern cars two main types of supports are used - rubber-metal and hydraulic.

Rubber-metal bearings

The design of rubber-metal supports is simple - the lower supports are two metal plates and a rubber cushion between them. Upper supports resemble a short one with silent blocks. One side of the "lever" is attached with a through bolt to the bracket on the body, the other - to the bracket screwed to the cylinder block. This kind of supports found most widespread due to reliability and cheapness in production.

Body vibration reduction technology invented by engineers Chrysler called Floating Power

In some designs, the cushions of the lower supports are reinforced with springs to stiffen and increase elasticity. Instead of rubber, some manufacturers use polyurethane - as a more wear-resistant material. Also, pillows using polyurethane are often used on sports cars, . In connection with the fashion for tuning, some small firms have launched the production of polyurethane supports for all more or less current models cars. Rubber-metal and polyurethane supports are also classified according to collapsible and non-collapsible design.

Hydraulic supports

Hydraulic supports are a more advanced mechanism. Such supports can be adjusted to different engine speeds and effectively dampen vibrations at low and high speeds. The supports consist of two chambers, with a membrane between them. The chambers are filled with propylene glycol (antifreeze) or a special hydraulic fluid.

To further reduce vibration in business class vehicles, mounts are used not only to mount the engine to the subframe, but also the subframe to the body, forming a double protection

The movable diaphragm dampens vibrations on the engine. At high speeds or when the road is uneven, hydraulic fluid is activated. Under pressure, through special channels, it flows from one chamber to another, making the support rigid. Rigid support dampens strong vibrations.

Hydro bearings can be:

WITH mechanical control. The design of such supports is calculated specifically for each car model. Already at the stage of development of a particular car model, the question is solved: what task for the support will be the main one - comfortable sound insulation on Idling or effective vibration damping at speed;
WITH electronic control. Such supports are able to respond to changes in the engine vibration mode over a wider range; the rigidity of the support is electronically changed depending on traffic situation. These are new generation mounts that are able to provide the same comfort when the engine is running in different modes.

Technological progress in the creation of engine mounts

It is worth highlighting the so-called dynamic supports, which use a liquid with magnetic properties (with metal particles), which changes viscosity under the action of magnetic field. Electronic sensors monitor turns and accelerations. Depending on the driving style and the condition of the road surface, under the influence of electromagnets, the fluid changes properties, adjusting the rigidity of the supports.

The average "service life" of rubber-metal engine mounts exceeds 100 thousand kilometers

Dynamic bearings differ from electronically controlled hydraulic bearings in a unique way. electromagnetic system. This is a relatively new invention of the American company Delphi. cutting edge technology has already found practical application in production cars: adapted for sports version GT3 Porsche company in 2011.

Operation and replacement

Wear and tear of bearings can cause unnecessary stress on the engine. This can quickly lead to malfunctions in its operation. Therefore, the condition of supports and fasteners must be monitored periodically. Checking the tightness of nuts and bolts, removing oil and dirt from the rubber pads - all these simple actions help to extend the life of the supports. Often, abnormalities in the supports are indicated unusually strong vibration body (which is especially felt when parking with the brakes pressed in a car with), as well as extraneous noise in the engine area.

Checking the condition of supports

The condition of the engine mounts is easy to check. Try successively switching the automatic transmission mode (or manual transmission gear) from D (1st gear) to R ( reverse). When changing gears, each time move a few centimeters forward and backward. If the bearings are in poor condition, you will feel jerks in the transmission, regardless of the type of gearbox (and in a car, the manual transmission is also on the gearbox control lever). In addition, the failure of the supports can cause jerks in the transmission when driving on high speed and gear shifting. Often, motorists tend to attribute these jerks, but before you go to diagnose the box, you should check the condition of the supports.

The supports must be replaced if, when viewed from the pit, cracks are visible and severe damage on the rubber parts or they have separated from the metal base. A leak hydraulic fluid also serves as a reason for the immediate replacement of supports.

engine support- fastening device with which power unit mounted on a car. In addition to the function of fasteners, it also functions as a cushion. According to this support is often called engine mount, and in English it sounds like engine mount. Also, depending on the design, the support may be called a "guitar", since the shape resembles this musical instrument.

As a rule, not one, but several (most often three) supports are used. Their task is to absorb the vibrations of a running motor and keep it in the most static position. Since in the work it will definitely vibrate, and this fact does not depend on the degree of its power and perfection. Mounting the engine on a support-pillow allows not only to increase ride comfort, but also to protect the power unit from shocks and shocks when moving over bumps.

Initially, the supports were simple metal fasteners, pulling the engine rigidly to the supporting structure. In fact, only the engine mount bracket in the modern sense was used. Then rubber cushions were added to the mechanism, which increased the elasticity of the mount, thanks to which it was possible to provide a more elastic motor suspension. Such a rubber-metal engine mount is widely used today.

Where is the engine mount

Many car owners do not even know what the supports look like, let alone where they are. Since if you do not climb under the car, then the support pillows are hidden from the eyes, only the top one is clearly visible from the engine compartment. The installation locations and the number of support points for the engine on the car body depend on the type and location under the hood of the engine and gearbox, as well as the brand of the car itself. The main task of installing the mount is reliability and minimal displacement on the sides during operation. The classic scheme of installing the engine on supports at 3 points from the bottom and 2 points from the top. By the way, not only ICE machines mounted on such a pillow, and the gearbox is also mounted on rubber-metal supports. Therefore, it is necessary to clearly distinguish where the engine is and where the gearbox is.

Types of supports

Modern engine mount May be rubber-metal or hydraulic.

For rubber-metal supports, the design is extremely simple: a pair of plates made of steel or other metal with a not too thick gasket between them, made of good wear-resistant rubber. This is the cheapest and most popular engine mount now. In some models, springs are additionally mounted in the pillows, which increase rigidity and buffers, which allow some softening of the most severe blows. Increasingly, new cars are being produced with polyurethane cushions, due to its greater wear resistance. It is the polyurethane pillow of the engine mount that is used in sports cars, as it improves to optimize stiffness. The rubber-metal engine mount can be collapsible or non-collapsible.

Engine hydraulic cushion device.

The hydraulic engine mount is considered a much more modern design. Such systems are able to adapt to the operation of the engine in various conditions and effectively dampen any vibrations. The engine support cushion is also made of three main elements, but here it is a pair of chambers, between which there is a membrane. Each of the chambers is filled with antifreeze or hydraulic fluid. The task of the movable membrane is to eliminate the slight vibration that occurs at idle and low speed on a flat road. High-speed vibrations are eliminated by hydraulic fluid. Under the influence of changing pressure, it moves between the chambers, increasing the rigidity of the support, which allows you to dampen even the strongest vibrations.

hydraulic engine mount in contrast to the rubber-metal support, it can have a different design. On this moment The following types of engine mounts are common:

mechanically controlled supports that are able to very effectively dampen one of the types of vibrations (idling, high-speed, strong shaking), so they are configured differently for each car model;
electronically controlled supports, which are mainly mounted on expensive cars, but are able to automatically change the stiffness characteristics to effectively counteract all types of operating vibrations;
dynamic supports based on the use of a magnetic metallized fluid that changes viscosity under the influence of a magnetic field, which in turn is controlled by automotive electronics, due to which the adaptability of the support settings is achieved.

However, only the first type of engine mount can be considered widespread, since the rest are too complex and expensive to be used on truly mass-produced cars.

Operation features

If excessive engine vibration occurs, check the integrity of the engine mount pad.

The engine mount is a part subject to wear, as it always works when the engine is running. The biggest test for supports is starting the engine, pulling away, and stopping the car. At such moments, the load on the supports is the largest. Wear or failure of this part leads to an increase in the load on the engine and an increase in the likelihood of its failure.

Cracks and gusts on the support cushion are visible if a scheduled inspection is specially performed for this, but symptoms such as increased vibration with feedback to the steering wheel when the engine is running or shifting gears with jerks, and if the cushion near the gearbox wears out, then it can knock out speed. Then there are clear facts on the face, you need to buy a set of new supports in line order and proceed with the replacement.

The appearance of cracks or delamination of the rubber part of the support from the metal one is a weighty argument for replacement.

Having at hand a set of keys, a jack and an inspection hole, in principle, you can change it yourself without any special skills, although there are cases where the procedure for replacing engine mounts is a very interesting thing.

It is not difficult to monitor the condition of rubber-metal bearings: you just need to check the integrity of the rubber gasket and regularly remove dirt and oil from it, tighten the mounting bolts.

On average, an engine mount serves about 100 thousand kilometers. But proper care allows shed lines of operation, not only for the engine mounts themselves, but also for the condition of the motor as a whole.

If the vehicle is equipped with hydraulic mounts, the hood must be opened and the engine started to test them. Next, you need to drive a couple of centimeters forward and backward. If something is wrong with the mounts, the engine will move out of place when starting and back into place when stopped, which will be accompanied by audible sounds.

Regardless of which support pads hold the engine on your car, the advice is the same for everyone. Do not abruptly destroy, thereby giving maximum load on supports, cross potholes and humps at low speeds, so that the vibrations of the motor are minimal, and therefore the vibrations that need to be absorbed by the engine mounts will not be significant.

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 a 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: at idle or at different engine operating modes.

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 way 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 a stick between the motor and the car body and try to shake the 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 viewing 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, breaks, leaks of 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.