Parts of the engine gas distribution mechanism experience heavy loads and high temperatures during operation. When heated, they expand unevenly, as they are made of different alloys. To ensure normal operation of the valves, the design must provide a special thermal gap between them and the camshaft cams, which closes during engine operation.
The clearance must always remain within the specified limits, so the valves require periodic adjustment, that is, selecting pushers or washers of the required size. Hydraulic compensators, sometimes called simply “hydriki” or hydraulic pushers, can eliminate the need to adjust the thermal gap and reduce noise on a cold engine.
Hydraulic compensator device
Hydraulic compensators automatically adjust the changing thermal gap. The prefix “hydro” implies the action of some kind of liquid in the operation of the part. This liquid is oil, which is supplied to the hydraulic compensators under pressure. A complex and precise system of springs inside adjusts the gap.
Various types of hydraulic compensators
The use of hydraulic compensators implies the following advantages:
- no need for periodic valve adjustment;
- correct;
- reducing noise when the engine is running;
- increasing the service life of gas distribution mechanism parts.
The main components of the hydraulic compensator are:
Principle of operation
The operation of a part can be described in several stages:
- The camshaft cam does not exert pressure on the compensator and is turned with its back side towards it, while there is a small gap between them. A plunger spring inside the hydraulic compensator pushes the plunger out of the bushing. At this time, a cavity is formed under the plunger, which is filled with oil under pressure through a combined channel and hole in the housing. The oil volume is drawn up to the required level and the ball valve closes under the action of a spring. The pusher rests against the cam, the movement of the plunger stops, and the oil channel is blocked. In this case, the gap disappears.
- When the cam begins to turn, it presses on the hydraulic lifter, moving it down. Due to the accumulated volume of oil, the plunger pair becomes rigid and transmits force further to the valve. The valve opens under pressure and the air-fuel mixture enters the combustion chamber.
- During the downward movement, some oil flows out from the cavity under the plunger. After the cam passes the active phase of influence, the work cycle is repeated again.
Operation of the hydraulic compensator The hydraulic compensator also regulates the gap that occurs due to natural wear of timing parts. This is a simple, but at the same time complex mechanism with precise fitting of parts.
The correct operation of hydraulic compensators largely depends on the oil pressure in the system and the degree of its viscosity. Oil that is too viscous and cold will not be able to enter the pusher body in the required quantity through the channels. Low pressure and leaks also reduce the performance of the mechanism.
Types of hydraulic compensators
Depending on the timing layout and installation location, there are four main types of hydraulic compensators:
- hydraulic pushers;
- roller hydraulic pushers;
- hydraulic supports;
- hydraulic supports, which are installed under rocker arms or levers.
Types of hydraulic compensators All types are slightly different in design, but have the same principle of operation. The most common in modern cars are conventional hydraulic pushers with a flat support under the camshaft cam. These mechanisms are installed directly on the valve stem. The camshaft cam acts directly on the hydraulic tappet.
With a lower camshaft, hydraulic supports are installed under the levers and rocker arms. In this position, the cam pushes the mechanism from below, and the force on the valve is transmitted through a lever or rocker arm.
Location options Roller hydraulic mounts work on the same principle. To reduce the impact of friction, rollers are used that contact the cams. Roller hydraulic mounts are used mainly on Japanese-made engines.
Advantages and disadvantages
Hydraulic compensators allow you to avoid many technical problems during engine operation. There is no need to adjust the thermal gap, for example, using washers. Hydraulic pushers also reduce noise levels and shock loads. Smooth and correct operation reduces wear on timing parts.
Among the advantages there are also disadvantages. Engines that use hydraulic compensators have their own operating characteristics. The most obvious of them is uneven operation of a cold engine at startup. Characteristic knocking sounds appear, which disappear when the temperature and pressure are reached. This occurs because the oil pressure is insufficient at startup. It does not enter the compensators, so there is a knock.
Another disadvantage is the cost of parts and maintenance. If replacement is required, it should be entrusted to a specialist. Also, hydraulic compensators are demanding on the quality of the oil and the operation of the entire lubrication system. If you fill in low-quality oil, this can directly affect their performance.
Main faults, possible causes and replacement
A knocking sound indicates a malfunction in the gas distribution mechanism. If there are hydraulic compensators, then the reason may be in them:
- Malfunction of the hydraulic pushers themselves: failure of the plunger pair or jamming of the plungers, jamming of the ball valve, natural wear.
- Low oil pressure in the system.
- Clogged oil channels in the cylinder head;
- Air entering.
It can be quite difficult for an ordinary car enthusiast to identify a faulty gap compensator. To do this, for example, you can use a car stethoscope. It is enough to listen to each hydraulic compensator to determine the faulty one by its characteristic knocking sound.
You can also check the functionality of the hydraulic compensators if you can remove them from the engine. When filled, they should not shrink. Some types can be disassembled and the degree of wear of internal parts can be determined.
Poor quality oil leads to clogging of oil channels. This can be corrected by replacing the oil itself, the oil filter and washing the hydraulic compensators. You can wash it with special liquids, acetone or high-octane gasoline. If it's the oil, this should help eliminate the knocking noise.
When replacing hydraulic lash compensators, you need to observe some nuances:
- New hydraulic pushers are already filled with an oil composition. There is no need to remove this oil. The oil is mixed in the lubrication system and air will not enter the system.
- You cannot install “empty” expansion joints (without oil) after washing or disassembling. This is how air enters the system.
- After installing new hydraulic compensators, it is recommended to turn the crankshaft several times. This is done so that the plunger pairs come into working condition and the pressure increases.
- After replacing the hydraulic tappets, it is recommended to change the oil and filter.
To ensure that hydraulic compensators cause as few problems as possible during operation, you need to use high-quality motor oil, which is recommended in the car’s operating manual. It is also necessary to follow the rules for changing the oil and filter. By following these rules, hydraulic compensators will last a long time.
As the name suggests, a hydraulic lifter is a hydraulic mechanism in a car engine.
It is responsible for maintaining a constant working gap in the valve mechanism of the internal combustion engine, since as the engine temperature increases, the dimensions of its parts and the gaps between them change.
The serviceability of hydraulic compensators guarantees trouble-free operation of the vehicle’s power unit, including during significant temperature fluctuations.
It maintains the clearance of the intake or exhaust valves of the internal combustion engine at the same level, including when wear occurs on the timing belt and the valve mechanism as a whole.
Ideally, during operation, the hydraulic compensator should not make any extraneous noise - rustling, grinding or knocking.
Any such sounds indicate a malfunction and the need to diagnose the mechanism.
Ignoring the problem in the future can lead to incorrect operation of the power unit, increased gasoline consumption, rapid wear of the valve mechanism and a critical drop in engine power.
With proper care and careful operation of the vehicle, hydraulic compensators last a long time and do not require any special attention.
However, sometimes problems with this node still occur.
So, for example, if the car already has a significant mileage, when there is natural wear of the plunger pairs of the hydraulic compensator, errors in maintenance or a significant interruption in the operation of the vehicle, depressurization of the system, oil leakage and its partial airing can occur.
This defect manifests itself on a warm engine with a slight knock in the timing drive.
You can try to solve this problem yourself by bleeding the hydraulic compensators.
Since the working fluid for hydraulic compensators is internal combustion engine engine oil, you need to make sure that the oil is fresh and its level is sufficient.
If everything is in order here, then you need to start the car and raise the speed to 2 thousand and let it run for 2 minutes.
Then let the engine run for about 3 minutes, changing the speed in the range from 1.5 to 3 thousand. Then release the gas pedal and let the engine idle for about 1 minute.
Most often, one pumping cycle is enough for the defect to disappear, but repetition may be necessary.
If after 2-3 pumping the noise in the timing drive persists, then it is necessary to look for a fault in the hydraulic compensators by diagnosing and disassembling the mechanism.
It should be noted that knocking is the most important external manifestation of a malfunction of hydraulic compensators.
It can occur for various reasons, the main ones being:
- . significant wear of the mechanism or a defect arising during operation, up to jamming, of hydraulic compensators;
- . low-quality, out-of-season or lost factory properties motor oil;
- . mud deposits in the internal parts of hydraulic compensators or disturbances in the internal combustion engine lubrication system.
The penetration of dirt and deposits into the internal cavities of hydraulic compensators is usually associated with a poorly functioning oil filtration system in the engine, a clogged oil filter, or a long period of operation of the internal combustion engine on old oil.
Therefore, it is very important to strictly comply with the requirements of the car manufacturer and promptly change the oil and oil filter, fill in oil with the appropriate engine markings and viscosity for the season.
You should also change the oil and filter after any malfunction of the internal combustion engine, for example, after it overheats, since such problems can lead to a change in the chemical properties of the engine oil.
If the hydraulic compensators are significantly contaminated, a characteristic knocking sound may appear both during a cold engine start and after it is heated to normal temperatures.
Experts believe that the knocking of hydraulic compensators that occurs on a cold engine, immediately after starting, is not a sign of their malfunction.
If after the engine warms up the knocking noise disappears, then this can be attributed to the normal operation of the mechanism.
When the engine starts, the oil in it does not have the viscosity required by the hydraulic compensators, which leads to a knocking sound, then the oil warms up, liquefies and the knocking noise disappears.
“Cold” knocking can also occur for the following reasons:
- Hydraulic compensator valve malfunction.
During engine downtime, oil can leak from the hydraulic compensator, which leads to systematic airing of the mechanism. During warming up or pumping, the pressure normalizes and the knocking disappears; - Significant contamination of the oil channels of the hydraulic compensator.
The higher the oil temperature, the less dense the dirt deposits in the channels become, due to which the knocking will disappear. Here you need to keep in mind that over time the channels can become tightly clogged, this will completely disable the hydraulic compensator, and it will knock constantly. In some cases, the situation can be corrected by using good quality engine oil cleaning additives from a trusted manufacturer; - Incorrect operation of the oil filter.
If its functional ability to pass oil is impaired, then when the internal combustion engine starts operating, the hydraulic compensators may experience oil starvation; when the oil reaches “working viscosity,” the knocking will disappear, but it is still better to replace the problematic oil filter.
Experts consider knocking hydraulic compensators in a warm engine to be the most dangerous. This can be a constant knocking noise on a warm engine at idle and under load while driving.
Diagnosis of a malfunction begins with determining the source of knocking in the internal combustion engine, because there are plenty of parts that can knock when a malfunction occurs in the engine: pistons, connecting rods, crankshafts and camshafts, etc.
The knock of the hydraulic compensator is quite characteristic - ringing, metallic, in a high pitch and comes directly from under the valve cover.
For diagnostic purposes, car service specialists often use a stethoscope.
As a rule, if the hydraulic compensator knocks constantly, this indicates its critical malfunction. It is necessary to dismantle the mechanism and determine its condition.
If the reason for the knocking of the hydraulic compensator in a warm engine is contamination of the oil supply channels, then it will be enough to disassemble and wash it. At the same time, it is recommended to inspect the internal combustion engine lubrication system, replace the engine oil and oil filter.
If the plunger pair jams, the hydraulic compensator must be replaced immediately.
When replacing one hydraulic compensator due to its jamming, it is better to replace the entire set so that in the future you do not have to open the internal combustion engine again to repair or troubleshoot other hydraulic compensators.
Only prepared hydraulic compensators should be installed.
New “factory” hydraulic compensators are filled with an oil solution; there is no need to remove it; it will ensure trouble-free starting of the mechanism and will subsequently mix with the engine oil.
If a hydraulic compensator is installed after disassembling and washing, then you must first fill it yourself with engine oil in order to avoid airing the mechanism and shock loads on the engine after it is started.
Replacing hydraulic compensators has its own technical features related to establishing the correct working position of the plunger pairs, so it is better to entrust this work to car service professionals.
Moreover, the engine is the most expensive part of any car and experiments with its parts are usually expensive.
Check out our engine repair prices
How much does it cost? The prices for such work are quite reasonable. Call us and see for yourself!
| Name | Engine | Domestic | Foreign cars | |
| Troubleshooting engine rub/hour | from | 1000 | 1250 | |
| Chain shoe (replacement) | from | 1000 | standard | |
| Cylinder block (boring) | from | 2700 | 2700 | |
| Inserts (replacement) | from | 5000 | standard | |
| Hydraulic compensators (replacement) 16 valves | 16 valves | from | 2500 | standard |
| Hydraulic compensators (replacement) 8 valves | 8 valves | from | 1900 | standard |
| Hydraulic valve tappets (replacement) V-shaped | V-shaped | from | - | standard |
| Hydraulic valve tappets (replacement) single row | single-row | from | 3000 | standard |
| Hydraulic valve lifters (replacement) opposed | opposed | from | - | standard |
| Block head (repair) with c/o single row | from | 6000 | 7000 | |
| Block head (s/u) single-row | from | 4000 | 5000 | |
| Camshaft bed cover (glued) with/u | from | 3200 | 5000 | |
| Cylinder-piston group (replacement) | from | 5000 | standard | |
| Engine (w/w) | from | 4000 | 6000 | |
| V-shaped engine (repair) overhaul with c/o | V-shaped | from | - | 25000 |
| Single-row engine (repair) overhaul with c/o | single-row | from | 18000 | 24000 |
| Boxer engine (repair) overhaul with c/o | opposed | from | - | standard |
| Ignition (setting) timing | from | 450 | 650 | |
| Motor protection (installation) | from | 400 | 400 | |
| Engine protection (w/o) | from | 130 | 130 | |
| Carburetor (replacement with adjustment) | from | 550 | standard | |
| Carburetor (repair with c/o) | from | 1000 | standard | |
| Valve (grinding in) for 1 piece | from | 300 | 500 | |
| Valve clearance (adjustment) 16 valves | 16 valves | from | 1800 | 2200 |
| Valves (adjustment) clearances 8 valves | 8 valves | from | 1100 | 1200 |
| Crankshaft (grinding) | from | 1800 | 1800 | |
| Intake manifold (w/w) | from | 1800 | standard | |
| Oil seals (replacement) 16 valves | 16 valves | from | 3500 | standard |
| Oil seals (replacement) 8 valves | 8 valves | from | 2500 | standard |
| Compression rings (replacement) V-shaped | V-shaped | from | - | standard |
| Compression rings (replacement) single row | single-row | from | 10000 | 15000 |
| Compression rings (replacement) opposed | opposed | from | - | standard |
| Generator bracket (replacement) | from | 650 | 850 | |
| Valve cover (s/u) | from | 550 | 600 | |
| Oil pump (w/o) V-shaped | V-shaped | from | - | standard |
| Oil pump (c/u) single row | single-row | from | 1100 | 1400 |
| Oil pump (c/u) opposed | opposed | from | - | standard |
| Engine oil+filter without flushing (replacement) | from | 400 | 400 | |
| Engine oil + filter with flushing (replacement) | from | 450 | 450 | |
| Oil receiver (replacement) | from | 1100 | 1300 | |
| Chain tensioner (replacement) | from | 1000 | standard | |
| Rear engine mount (replacement) | from | 350 | 600 | |
| Left engine mount (replacement) | from | 400 | 700 | |
| Front engine mount (replacement) | from | 350 | 700 | |
| Right engine mount (replacement) | from | 400 | 700 | |
| Head gasket (replacement) V-shaped | V-shaped | from | - | standard |
| Head gasket (replacement) single row | single-row | from | 3800 | standard |
| Head gasket (replacement) opposed | opposed | from | - | standard |
| Valve cover gasket (replacement) with sealant strip | 650 | 800 | ||
| Valve cover gasket (replacement) | from | 550 | 600 | |
| Oil pan gasket (replacement) | from | 1100 | 1500 | |
| Distribution shaft with valve adjustment (c/a) V-shaped | V-shaped | from | - | standard |
| Distribution shaft with valve adjustment (c/u), single row | single-row | from | 1100 | 3500 |
| Distribution Shaft with valve adjustment (c/u) opposed | opposed | from | - | standard |
| Alternator belt (replacement) | from | 350 | 650 | |
| Alternator belt (adjustment) | from | 100 | 100 | |
| Timing belt (replacement) V-shaped | V-shaped | from | - | standard |
| Timing belt (replacement) single row 16 valves | single-row | from | 1500 | standard |
| Timing belt (replacement) single row 8 valves | single-row | from | 950 | standard |
| Timing belt (replacement) opposed | opposed | from | - | standard |
| Air conditioner belt (replacement) | from | 350 | 650 | |
| Drive belt (replacement) | from | 550 | 650 | |
| Timing belt tensioner roller (replacement) single row 16 valves | from | 1500 | standard | |
| Timing belt tensioner roller (replacement) single row 8 valves | from | 750 | standard | |
| Drive belt roller (replacement) | from | 650 | 650 | |
| Rear crankshaft oil seal (replacement) with the box removed | from | 200 | 250 | |
| Rear crankshaft oil seal (replacement) with box removal | from | 2100 | 3700 | |
| Front crankshaft oil seal (replacement) with timing belt removed 16 valves | from | 250 | 350 | |
| Front crankshaft oil seal (replacement) with timing belt removed 8 valves | from | 250 | 350 | |
| Front crankshaft oil seal (replacement) with timing belt removal 16 valves | from | 1700 | standard | |
| Front crankshaft oil seal (replacement) with removal of timing belt 8 valves | from | 850 | standard | |
| Camshaft oil seal (replacement) | from | 750 | standard | |
| Candles (replacement) set 4 pcs | from | 350 | 400 | |
| Glow plugs (replacement) | from | standard | standard | |
| Valve seat (replacement) | from | 550 | standard | |
| Turbine (repair) | from | standard | standard | |
| Turbine (w/w) | from | standard | standard | |
| Chain damper (replacement) | from | 1000 | standard | |
| Oil filter (replacement) | from | 150 | 150 | |
| Timing chain (replacement) V-shaped | V-shaped | from | - | standard |
| Timing chain (replacement) single row | single-row | from | 1500 | 4000 |
| Timing chain (replacement) opposed | opposed | from | - | standard |
*The prices shown are indicative, valid as of June 10, 2018, and are subject to change without prior notice. This is not a public offer.
The first engine with hydraulic compensator was installed in Cadillac in 1930. At that time, no one thought about servicing power units, so “hydrikis,” as they are now popularly called, became truly in demand only in the 80s. Then the Japanese auto industry entered the world market and then conquered it.
But the use of these elements led to the complication of the engine design and increased the cost of the machines, so they began to be installed less frequently. Engine reliability has lost some of its importance for economic reasons, but owners of cars with hydraulic compensators can still consider themselves lucky.
Hydraulic compensator - what is it in the engine?
In engines created during the development of the automotive industry, thermal clearances were regulated by special mechanisms. The gap appears as a result of valve wear. It was recommended to adjust the valve system every 15,000 km. It was necessary to open the cylinder head, and only a qualified craftsman could do this.
But the auto industry continued to develop, and experts developed a device that maintains valve clearance without adjustment. During its operation, timing belt wear is taken into account. The device acts as a pusher, the design of which includes springs. They are in constant motion and change in size in proportion to the gaps. This mechanism is called a hydraulic compensator.
What do hydraulic compensators look like?
There are compensators for engines made according to SOHC and DOHC schemes. They differ in design, but only slightly. Any hydraulic pusher is installed in a metal case that cannot be disassembled. In SOHC engines it is placed in the sockets of the valve rocker arms, in DOHC engines - in the cylinder head sockets. The device consists of:
- plunger;
- its bushings;
- valve spring;
- ball valve;
- plunger springs.
Why are hydraulic compensators needed?
As the engine warms up to its operating temperature, parallel heating of other power unit devices occurs. The parts expand, causing the gaps between structural elements to decrease.
If we talk about timing, the accuracy of the gaps is very important - the smooth operation of the internal combustion engine depends on it. Valve clearances can be adjusted either manually or using special devices. The valves are under constant thermal and shock loads. By the way, all timing parts warm up unevenly, and natural wear is the main “disease” of the valve mechanism.
The thermal gap ensures normal operation of the valve system. Due to contact with hot gases, the exhaust valves heat up much more than the intake valves, which is why the gaps here are larger. The adjusted clearances are constantly changing due to wear of the mechanism and for other reasons. Their changes lead to premature wear of the timing belt. The valves begin to knock, fuel is consumed rapidly, and engine power drops.
Exhaust valves suffer much more than intake valves. Hot gas passing through damaged seals can destroy the valve seat and valve plate. And the formation of a gap leads to an increase in shock loads and a loss of power by the power unit.
Adjustment of the gaps can be done manually - but only with experience and appropriate skills. Adjustments should be carried out every 15,000 km. The procedure must be carried out taking into account temperature fluctuations - the average value is not taken into account here. With hydraulic compensators that automatically adjust the clearance, much fewer problems arise.
How do hydraulic valve compensators work?
The operating principle of hydraulic compensators is a rational change in the gap between valves and parallel axes. All changes are made automatically. Movements of parts occur due to the supply of oil and the action of springs. With this mechanism, there is no need to regulate the valve system - the valves open and close without external intervention. When the gap changes, the pusher “presses” the valve to the required position.
The hydraulic compensator device includes a plunger pair and a valve that conducts oil. Oil is extremely important for the compensator. The compression rate is low, so oil pressure is the main force behind the hydraulic valve.
Where is the hydraulic compensator located?
At the very top of the power unit is the cylinder head. The camshafts rotate inside it. In appearance, the camshaft resembles a regular axle with cams, under which compensators are located. The oil easily fills them when they are in a relaxed state, but its release occurs within a few hours. The supply of working fluid is carried out from a channel located in the bearing housing through a special hole.
The main elements of the device are plunger pairs installed in the cylinder head instead of conventional bushings and bolts. The plunger constantly presses on the valve lever, pressing it against the camshaft cam.
Types of hydraulic compensators
There are 4 types of devices:
- Hydraulic pusher. Suitable for modern car models. Adjusts the clearances between the camshaft and the valve.
- Hydro support.
- Hydraulic support for work in rocker arms and levers. Now this device is almost never used. It was actively used in previous models of gas distribution mechanisms.
- Hydraulic pusher on a roller basis.
Today, hydraulic pushers are increasingly used, and hydraulic supports are gradually becoming a thing of the past. All 4 designs are found.
Pros and cons of use
The direct purpose of the compensator is to regulate the gap that forms between the valve and the shaft. Without this normal condition, the power unit will not be able to operate. This happens automatically due to oil pressure. The advantages of using the mechanism are:
- fuel is consumed more slowly;
- dynamics improves;
- the motor runs smoothly and silently;
- the service life of the timing belt increases, the accuracy of its phases increases;
- The power and service life of the internal combustion engine increases.
There are also some downsides. As already mentioned, the main pushing force of the system is oil. Only high-quality, and therefore expensive, oils should be used. Synthetic hydraulic fluid is preferred. In addition, the oil has to be changed frequently, and this also “smells” of impressive expenses.
Compensators often become clogged - this is another disadvantage of the mechanism. The timing drive begins to make a lot of noise, and the performance of the power unit deteriorates.
The structure is difficult to repair - it is better to entrust this matter to specialists. To avoid having to constantly visit a car service center and change hydraulic compensators, you need to ensure that the engine is clean. As soon as necessary, change the oil in the system and rinse the engine thoroughly. Malfunctions must be eliminated immediately after they are identified.
Remember: failure of the compensator can cause serious problems with the internal combustion engine. So why not just follow the rules of operation?
The gas distribution mechanism of engines has been significantly modernized over time. The development has not spared the valve structure of internal combustion engines. At first, the resulting gaps between the valves and the camshaft were adjusted manually, then mechanical adjusters appeared, but hydraulic compensators became the pinnacle of adjustment. Don't know much about such details? Then be sure to read the article below, which will help everyone understand why hydraulic compensators knock, what they are and whether they can be repaired.
Design and principle of operation of hydraulic compensators
Any more or less experienced motorist knows that the engine valve mechanism regulates the intake of the fuel mixture into the cylinders and the release of exhaust gases from them. During their operation, the engine valves open in pairs and, naturally, operate under enormous load conditions, which is associated with the high combustion temperature of the fuel. To minimize the negative properties of thermal expansion, thermal gaps are provided between the units of the entire timing belt, which are regulated by a standard hydraulic compensator.
The difference between hydraulic compensators and other valve clearance regulators is that the former operate completely automatically, while other mechanisms require some form of participation from the motorist in his life. What does it mean? This means that in the absence of hydraulic compensators, the car owner, at some intervals, must personally set the thermal clearance of the valves and carefully monitor them during operation of the unit.
In simple words, the hydraulic compensator device is a linkage mechanism installed between the engine camshaft and each valve. The part works on the principle of a plunger pair and oil circulation, while acting as a “gasket” between the previously noted timing elements. As a result, it turns out that, depending on the temperature conditions of the engine, there is always interaction between the camshaft and the operating valve, and most importantly, a correctly adjusted thermal gap.
Why does hydraulic lifters knock?
From many motorists you can often hear phrases like:
- “Why do hydraulic compensators knock when cold? What to do?";
- “Why do hydraulic compensators knock when hot? Where to regulate?”;
- “The hydraulic compensators started knocking. How can I fix them now?
Let us note right away: formulating the problem in this way is initially incorrect. It is important to understand one simple thing - hydraulic valve compensators cannot knock; the valve mechanism itself knocks due to improper functioning. But the latter is often caused by faulty hydraulic compensators. But first things first.
It was noted above that any type of hydraulic compensator is a hydraulic mechanism that operates due to a plunger pair and oil supplied to it from the motor. That is, the reason for the knocking of hydraulic compensators or valves, as it would be more correct, lies either in the incorrect operation of the plungers, or in problems with the oil supply of this mechanism. To be more precise, an unpleasant sound can appear for several reasons:
- There is not enough oil reaching the hydraulic compensators or it is of very low quality. As a result, the plunger pair does not receive proper lubrication, pressure does not appear in the system and clearance regulation does not occur. Naturally, valve knocking begins, provoked by an incorrect thermal gap;
- The channels of the cylinder head or the hydraulic mechanism itself are clogged with wear. This phenomenon occurs due to improper use of oil. That is, the lack of a timely oil change or its excessive burnout can clog the oil channels and turn the working unit into a completely faulty hydraulic compensator;
- The hydraulic mechanism itself has failed. There are two main possible failures here: a wedge of the plunger pair or incorrect operation of the ball valve that acts directly on the thermal valve of the motor. This can happen either due to carbon deposits that appear due to the use of bad oil, or due to defects during assembly of the mechanism. Physical wear and tear of the unit is practically excluded, because it is actually eternal. In any case, only a thorough check of the hydraulic compensators and a professional look at their condition will help determine the exact cause of the malfunction.
It makes sense to complain about the incorrect operation of hydraulic mechanisms in the timing belt design only if the presence of other breakdowns in the system is excluded (especially valve breakdowns). Under other circumstances, repairing hydraulic compensators will look like something unnecessary and pointless.
Repair of hydraulic compensators
Replacing hydraulic compensators or repairing these timing elements yourself is, frankly speaking, very rarely required. This is due to the fact that the design of the mechanisms is thought out to the smallest detail and their actual breakdown is often caused not by the working conditions, but by the carelessness of the machine owner. The latter, of course, is not available to all motorists, which is why not many require hydraulic lifters to be repaired.
In any case, knowledge is power, so information about the symptoms and general principles of repairing hydraulic slack adjusters will be useful. First, let's pay attention to the signs of hydraulic compensator failure. Often they are more than transparent and are represented by the following list:
- the motor began to work unstably;
- movement dynamics were disrupted;
- “knocking” noises appeared in the operation of the internal combustion engine;
- burnt valves;
- fuel consumption has increased.
Naturally, the more symptoms appear, the greater the grounds for thinking about repairing hydraulic compensators yourself. Why do it yourself, and not at a service station? It's simple. There are no particular difficulties in repairing parts, so giving a considerable amount of money to other people is probably pointless.
Returning to the question of how to check hydraulic compensators for correct operation, we will have to state an unpleasant thing for many motorists - without removing the elements from the engine, diagnostics will not be possible. Taking into account this feature of the repair, we will consider replacing and checking the hydraulic mechanisms together. In general, the process of repairing hydraulic compensators looks like this:
- First of all, we completely change the engine oil and oil filter. If after this the knocking or other symptoms of a breakdown do not go away, proceed to the next step. Don’t forget that after changing the oil, the hydraulic compensators need to be pumped. How to bleed hydraulic compensators? No, the system will do everything itself after starting the engine. More precisely, the oil pump will pump new lubricant into each hydraulic mechanism and only after that they will stop knocking, which will allow you to evaluate their new work. Often this takes 5-15 minutes, no more;
- So, apparently, there is no effect? Then we partially disassemble the motor to access the valve mechanism. On many car models, it is enough to remove the cylinder head and dismantle other engine components that interfere with access to the valves;
- After this there are two options:
- The first is to find a faulty hydraulic compensator. The procedure is not complicated and is carried out as follows: we move the rocker arm and pusher rod of each valve as far away from the hydraulic mechanism as possible and try to press the latter with a drift. If the compensator goes down under significant pressure, then it is in good order, otherwise the part should be removed for a better check;
- The second is to remove all hydraulic compensators to check each one. When choosing this option, a standard disassembly of the valve mechanism and the elements of interest to us are carried out, respectively.
- Having carried out the operations described above, all that remains is to replace the faulty timing element and return the car to its original condition. If the mechanisms were disassembled, then it is necessary to check their internal condition and clean them of carbon deposits. If everything is normal with the regulator, then the hydraulic compensator should be installed back into the motor structure and only then checked for functionality. Under other circumstances, the unit must be completely replaced. We will not talk in more detail about how to disassemble the hydraulic compensator, since this procedure is not so complicated and can be done by any motorist. The main thing is to act carefully and slowly.
It is probably pointless to provide more information on how to replace hydraulic compensators. Practice is more important here, so stock up on a basic car repair kit and head to the garage, of course, if you need something like this.
Prevention of breakdowns
As it became clear, checking, repairing and installing hydraulic compensators are simple procedures, and adjustment of the unit is not required at all. Despite this, absolutely no motorist wants to allow car breakdowns, so it would be advisable to talk about preventing malfunctions and compensators.
The main thing in prevention is to remove cheap and low-quality lubricants from the “diet” of the car engine. How can you identify a good oil manufacturer, you ask? The answer is very simple - according to reviews from motorists. According to research from our resource, the best oils are from the following companies:
- Liqui Moly is a German organization famous for its huge number of lubricants for cars. Let us immediately note that there is no need to buy additives for hydraulic compensators from Liqui Moly (such products from any manufacturer only clog the engine cavities), but motor oil is a must;
- Motul is a British manufacturer of the same lubricants for cars. Perhaps the most important competitor in its field of activity for Liqui Moly, what is best for you - decide for yourself. We can definitely say that both manufacturers are worthy of attention and respect;
- Castrol (Castrol) - as well as Motul, a manufacturer from Foggy Albion. In terms of status and reviews, this company is, of course, inferior to those discussed above. However, compared to other representatives of the market, it is Castrol that has the best reviews about its products, so our resource can only recommend its oils for purchase.
In addition to selecting lubricant, it is advisable to remove hydraulic compensators at least once every 80-100,000 kilometers for cleaning and quality check. Otherwise, these timing elements do not require maintenance and, if used correctly, will cover the full service life of any car’s engine.
In general, there is nothing more to say on today's topic. We hope that the material presented above was useful to you and provided answers to the questions you were interested in. Good luck on the roads and in car maintenance!
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