engine support- a mounting device with which the power unit is mounted on the 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 along 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 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 viewing 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 on not high 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.
The engine mount (motor mount) is designed to reduce vibration loads and oscillatory movements in engine compartment and to minimize the transfer of such loads to the vehicle body.
In other words, the engine is not directly attached to the load-bearing elements of the car body, but with the help of special supports, which are also called pillows.
Simply put, an engine mount is a gasket between the engine and the body. Naturally, any problems that are associated with the motor mounts lead to the fact that the efficiency of the engine mounts drops and severe discomfort occurs. Also, for a number of reasons, the operation of the vehicle can be significantly complicated.
Read in this article
Engine mount: what it affects and how it works
On various domestic and foreign cars until the 80s, the engine mount was actually a dense rubber that was screwed to the engine and body. This solution was widely used on cars, which at that time were overwhelmingly with rear wheel drive. At the same time, simple supports coped well with their tasks.
However, in the future, the bodies became lighter, the thickness of the steel decreased, the requirements for passive safety etc. As a result, pillows have evolved into a more complex piece of metal and rubber. On elite car models appeared hydraulic supports engine, which are able to provide maximum comfort compared to other analogues.
So the engine of the modern passenger car with front-wheel drive is often mounted on 4 or 5 legs. As a rule, two pillows are located at the checkpoint, the rest are attached to the power unit. The engine and box itself have a rigid connection.
As for the internal combustion engine, it is customary to single out the right pillow, as well as the front and rear. The right engine mount is mounted on the front right side member. This support is located on top. The front engine mount is often attached to the front beam, located below. The rear cushion is also at the bottom, can be attached to the bottom or to the subframe. By the way, on many models rear support structurally absent.
If we talk about the design, rubber-metal engine mounts may differ in shape and materials of manufacture, but often they are based on metal cylinder into which the silent block is pressed.
The main task is a reliable, but not rigid fixation of the internal combustion engine, while the pillow simultaneously absorbs vibrations and dampens the resulting vibrations. As a result, the controllability of the vehicle improves, the engine itself turns out to be less vibration-loaded, it suffers less from vibrations attachments, vibrations are not strongly transmitted to the car body, etc.
Torn engine mount: signs
Like any other detail, support power plant also has a limited lifespan and fails over time. On average, pillows modern cars designed for at least 100-120 thousand km, although in practice these elements may need to be replaced both earlier and much later than this period.
Usually the cause of the problems is the rubber insert, which simply cracks and tears from the load. Less often, cracks appear in the metal part of the support, the installation sites of fasteners are broken, etc.
One way or another, the following symptoms usually indicate a malfunction of the motor pillows:
- The engine itself runs smoothly, but the driver feels a clear increase in vibrations in the body, on the steering wheel, on the gear knob, etc .;
- At the moment of starting to move from a place, as well as during braking, you can hear clicking or muffled knocks in the engine compartment;
- When driving on rough roads, blows are heard from the front of the car, such blows are in many cases felt on the gearshift lever, gear shifting on the “mechanics” at this moment can be difficult;
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 on rough roads. 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-metal 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 at idle and while driving indicate 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 generated 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. The front and rear support allows you to reduce engine vibration at idle and in high load mode.
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 inexpensive 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 high speeds (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.
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 The Highlander uses an active engine mount (ACM, Active Control Mount) at the front combined with passive hydraulic mounts at the rear. 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. hydraulic fluid in support. 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 on Idling. 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 ACMs are conventional hydraulic mounts with hydraulic lines connected to the chambers. 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.
