Hydraulic lifters knock on hot causes. The hydraulic lifter knocks, what should I do? Manifestation of negative noises "hot"

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For the long-term operation of the car, it is important not only to visually inspect the mechanisms, but also to listen to the sounds that it makes. For example, by ear, you can diagnose a case when hydraulic lifters are knocking. To facilitate the operation of the car and eliminate the need to regularly adjust the valve clearance, manufacturers have developed and began to use hydraulic lifters in series. However, their use not only simplifies the life of the car owner, but can cause anxiety about what to do if there are extraneous sounds from the engine compartment.

Article author: mudriy_lev
Specialization: repair of autogenerators and servos in a car.
Place of work: service center. Experience: 2 years.
Education: higher - electrical engineer, specialized secondary - mechanic of mechanical assembly works.

The most common reason why hydraulic lifters knock is oil. The car owner needs to pay attention to the following factors that can cause the knock of hydraulic lifters:

the oil must comply with the manufacturer's recommendations
oil change must take place on time
the oil filter is changed simultaneously with the oil change
the oil must be suitable for the climatic conditions

The most important thing when choosing an oil is that its viscosity complies with the manufacturer's recommendations. Hydraulic lifters will knock if:

the oil is too viscous
the oil is too thin

In the case of too viscous oil, hydraulic lifters usually knock on a cold one, since insufficient oil is supplied through the channels. As the oil heats up, it becomes more liquid and is able to fill the entire system without hindrance. Therefore, a knock on a hot one usually goes away.

If the oil is too liquid, then on some cars a situation arises that the oil pump is not able to create optimal pressure in the system. As a result, oil starvation occurs, and the knock of hydraulic lifters, which is more clearly audible on a warm engine. In the event of a breakdown of the oil pump, a similar situation arises.

The same situation can arise if the oil is not suitable for climatic conditions.

To eliminate the knock of the hydraulic lifters, in this case, it is necessary to change the oil. If the oil is changed in a garage, then it is necessary to check the full compliance of the oil with the requirements of the automaker.

Oil is changed during maintenance for a reason

In the case of prolonged operation of the car without changing the oil, the following situations may occur, causing the knock of the hydraulic lifters:

canal pollution
oil loss of its qualities

In the first case, knocking will occur when the engine is cold. The oil supply channels are clogged and therefore it is impossible to create the required pressure in the hydraulic lifters. In the process of warming up the oil, deposits flake off and oil flows through the entire system. After cooling down, all the dirt will settle on the walls and re-clog the channels. This will cause a knocking sound every time the engine is warmed up.

If the oil has lost its qualities due to old age, it can begin to foam. Such oil is not able to create the required pressure and its prolonged presence in the engine will lead to significant damage.

If the oil is old, it must be replaced. Do not immediately fill in expensive oil. It contains high-quality detergent additives that can remove dirt from the walls. This will lead to even more clogging of the channels of the oil system. Therefore, before filling with good oil, after prolonged operation with old oil, it is necessary to flush the system with a special agent.

Knocking of hydraulic lifters due to engine overheating

Engine overheating can cause the oil to lose its qualities. After the engine boils, it is imperative to eliminate the cause of its overheating and change the oil.

The use of overheated oil not only causes the knock of hydraulic lifters, but also leads to increased wear of all elements of the internal combustion engine.

The oil should only be changed in conjunction with the oil filter, which can also cause knocking.

If the filter is clogged, it is difficult for oil to pass through it. This leads to a decrease in the pressure in the system. In this case, the knock of hydraulic lifters from the engine compartment will be heard both cold and hot.

A complex oil and filter change can remedy this situation.

Strong mechanical wear

If a car with high mileage and hydraulic lifters have not been changed for a long time, a knock on their side may be due to excessive wear.

A visual inspection will allow you to understand how to identify a knocking hydraulic lifter. In case of wear of the striking surface, the knocking hydraulic compensator will be visible immediately by the dents from the camshaft. If outwardly all hydraulic lifters look normal, it is necessary to alternately press on them with a piece of wood or a screwdriver. The effort should be the same. In this way, it is possible to identify both a jammed and a hydraulic compensator that does not hold pressure.

When knocking is the norm

After changing the oil, the hydraulic lifters are empty. After the engine starts running, oil will begin to flow into them. But until normal pressure is created, a knock from the hydraulic lifters is considered the norm. During subsequent warming up of the engine, there should be no extraneous sounds.

The case when the hydraulic lifters knock on a cold or hot one is not a critical breakdown, since this allows you to continue to operate the car, but in order to prevent damage to the timing elements, it is advisable not to delay the elimination of this breakdown.

), ensuring its performance, by maintaining an optimal clearance between the camshaft cam (or rocker arm) and its working surface.

The clatter of hydraulic lifters indicates a malfunction, the elimination of which will allow you to get the full return from the engine.

It consists of:

bodies with special grooves and holes;
plunger pair with spring and ball valve.

The upper end of the valve stem of the vehicle rests against the bottom of the plunger. That is, the compensator is an intermediate link between the valve and the timing shaft cam.

What's inside

The gap is adjusted automatically. The principle of operation of hydraulic lifters is based on a negligible oil compression ratio. At the moment when the holes (made specifically for the passage of lubricant) coincide in the cylinder head and the compensator housing, oil will enter it. Further, it enters the upper chamber of the plunger through the groove, and then, through the opened ball valve, fills the lower chamber.

Since oil is supplied under pressure, the plunger is squeezed out, pushing the compensator housing upward until it rests against the cam. The cam of the shaft, turning, presses on the hydraulic compensator, which goes down. The holes are closed, the oil flow is stopped and the ball valve is closed.

The oil has the property of incompressibility, therefore, the force of the timing shaft cam is transmitted through the hydraulic compensator to the automotive valve. It opens up. Further travel of the cam causes the valve spring to push it upward, and it closes.

Some of the oil may seep through the plunger ball seat in the opposite direction, increasing the clearance, but in the next cycle, when the holes in the oil lines match again, the oil volume will replenish and the clearance will normalize.

Timing operation leads to the depletion of the expansion joint surface, while the gap increases. Replenishment of the oil volume in the cycle normalizes it again. Thermal expansion of parts also affects the clearance, but here, too, the hydraulic compensator allows you to get rid of the excess.

Knock knock strife, because the consequences are different

How are these devices convenient? Those that perform their functions without requiring maintenance and special care.

You can not remember them until you hear a specific, specific knock of hydraulic lifters.

Moreover, it can appear only at startup and disappear as it warms up, or it can continue all the time.

What happens when the hydraulic lifters knock:

the functioning of the plunger pair stops;
valve heads burn out, followed by damage to the block head;
there are noises in the engine, which complicate the general diagnosis;
accelerating dynamics deteriorates.

Why do hydraulic lifters knock? There may be several answers, depending on the circumstances. It is necessary to establish the moment when the knocking begins. This helps to clarify the situation.

If you hear a knock of hydraulic lifters on a cold one, that is, immediately after starting and continues until the engine warms up, then the probable reasons may be the following:

The plunger valve allows oil to pass through when the engine is off.
Narrowing of oil channels by pollutants. At the moment of start-up, the oil has a high viscosity and does not enter the plunger, therefore, the hydraulic compensators knock on the cold one. When heated, the viscosity decreases and its penetrating ability increases.
High oil viscosity. The knock disappears as the fluidity increases.

This phenomenon is not very critical, although it should not be ignored. Often the "hydrics" knock only at the moment of start-up. This is due to the fact that when stopped, some of the engine valves freeze in the open position and the plunger valve "bleeds" a little oil.

These sounds should not be counted as signs of malfunction. This is acceptable on a cold engine. New hydraulic lifters will knock at start-up, because during long-term storage, some of the oil may leak out.

Well, what if the hydraulic lifters knock on a hot one? Although the question was posed somewhat incorrectly. Let's figure out why the knock appears when the engine starts and does not stop as it warms up. In this case, as in the previous one, there are several probable reasons:

Poor quality oil initially or has not been changed for a long time. The knocking usually stops after changing the oil.
Malfunction of the hydraulic compensator itself.
Dirty oil filter.
The knock of hydraulic lifters on hot occurs if the oil pump does not develop the required pressure.

There is one more reason, which, for some reason, manifests itself on the Prior. A knock in the expansion joints appears after changing the 5W40 oil to 0W40.

Taking action

So, hydraulic lifters knock, what to do? Do not panic. Such a phenomenon has not yet brought the car to exclusion from the transportation process.

The functioning of this important part is directly related to the lubrication system. If the hydraulic lifters knock, the probability that the oil has lost its original characteristics is quite high.

Do not immediately think about disassembling the motor. The first step is to change the oil and filter to eliminate knocking. After replacing, when starting, do not flinch from the knock of the hydraulic lifters, during the process of draining the oil, it will also leave them, and the plungers will fill when the oil pump starts.

If this does not help, then you need to find out which hydraulic compensator is knocking. The question arises, how to determine the one that needs to be changed? For example, a VAZ 2112 has 16 valves, how do you know which one is not functioning?

To do this, you need to put the camshaft cam (rocker arm) so that it does not interfere and try to push the compensator with a punch. A serviceable one is sold out if significant effort is made, a defective one will go down easily. It must be removed.

How to check hydraulic lifters without disassembling? A faulty one can also be detected when the engine is running.

The place of its installation is determined using a phonendoscope. Some craftsmen make a device using a metal rod and a resonator from an aluminum can. Experienced minders find out simply by ear. Further, the cause of the knock of the hydraulic lifters is eliminated.

After finding faulty parts, some car owners remove them in order to remove contaminants from the plunger by disassembling and flushing. Others go to remove and replace them. Often, after these manipulations, it is possible to eliminate the knock only for a while.

Analysis and analysis of the frequency of repair of these units suggests that their wear and tear and operating conditions are approximately the same, and hence their condition too. Therefore, it is recommended to replace the hydraulic lifters with a set.

Many motorists face this problem - hydraulic lifters knock on a hot engine. In our article we will talk about this unpleasant phenomenon. To begin with, the knock of hydraulic lifters can manifest itself not only hot engine, but also when it starts (cold). The appearance of a knock of hydraulic lifters in hot and cold engines can depend on the same or different reasons. There is an opinion that compensators knocking to hot more systemically. While on a cold engine, this impact sound can only appear at some moments.

First of all, any motorist must make sure that the impact sound that appears is emitting exactly hydraulic lifters, and not some other component or mechanism of an internal combustion engine. You only need to check it hot engine... However, this is not difficult to do, since the knock of the compensators has a characteristic sound. However, if you are in doubt about the diagnosis, then it is better to contact a specialist in a repair shop.

Now let's look at the causes of knocking in hydraulic lifters. There are several such reasons, however, it is worth noting that not all of them are the problem of expansion joints.

The first (most common) reason. Compensators knocking because low-quality oil was poured into the engine or it has not changed for a long time. To avoid impact sounds, we advise you to buy only high-quality engine oil from reliable suppliers.

The next reason is clogged channels through which engine oil should flow into hydraulic lifters... Moreover, there will definitely be a knock hot engine, but on a cold one it may not be. The thing is that while the engine is cold, the engine oil in it has the same viscosity, but as soon as the engine starts to warm up, the oil changes its viscosity and problems begin to appear. To remove this sound, you need to replace the engine oil and thoroughly flush the entire system. In addition, a more viscous engine oil may need to be used in the future.

The third reason is expansion joints knocking due to clogged oil filter. Engine oil simply does not fit the hydraulic compensators at the required pressure, as a result of which an air lock forms.

The fourth reason is a high or low engine oil level. In this case, the oil is enriched with air masses. While the engine is cold, the percentage of air in the oil is not yet high in order to make it compressible. After a little work, the engine heats up, the amount of air in the oil increases, making it critical. Resulting in hydraulic lifters start knocking.

The fifth reason is caused by problems with the oil pump. This happens with worn out pumps that do not produce the pressure required for the full functioning of the vehicle's lubrication system.

The sixth reason is the wear of the seat for the hydraulic compensator. As a result of engine heating, all its parts expand, respectively, the seat of the hydraulic compensator also expands and looses even more, which causes knocking.

The seventh reason is in the hydraulic lifter itself. Knocking occurs due to problems with the hydraulics and mechanics of the expansion joint.

As you can see, there are many reasons for the appearance of this kind of knocking. It is very difficult to understand them, and even more precisely to determine which of them is the main one. Although, you can not hesitate and just change the entire chain, starting from the oil pump and ending with the compensators themselves. This, of course, will lead to a positive result, but how much will it all cost?

In our opinion, the most correct solution for a novice motorist is to contact a normal specialist who certainly knows by what method to find the cause of the knock and how to optimally neutralize it.

Knock of hydraulic compensators (hydraulic jacks, hydraulic valves): what is the value?

You can go to the turbocharged car student for some knocking in the motor. Often dzherelo tsyogo knock dvigun (on cold chi on hot) - hydrocompensator(still seem to be: guides, guides).

Knock (creak) under the hood of the build-up step by step. Spohatku to make noise when cold start dvigun. As soon as it prodovzhuvati yo іgnoruvati, then knocking will і todі, if dvigun is already rozіgrіvya.

If you saw a similar noise, this would indicate an incorrect operation of the hydraulic compensators and timing valves.

What kind of knocking and what can be inherited?

Padinnya running characteristics
Blue (sivy) dim from a swirling pipe. A handful for skidding dvigun wraps, and todi permanently.
Changing the term of service to the timing drive, the wear of the head to the block of cylinders has been adjusted.
In the most vipadku: Having jammed the hydraulic valve => The valve is broken => Falling at the cylinder. Far - painful ...

How can you put down the knock of hydraulic compensators?

Gidrocompensators first "give the nobility" about those yak dvigun spriymє will fill olive

The main reason for the knock in the hydraulic staff є Olivie's lack of grip in the plunger pair. At all times, the hydraulic compensator does not come up again by adjusting the gap between the valve and the cam of the rotor shaft. When turning the stop start, give the hydraulic compensator on the critical, so that you can make a “scratching” sound until you knock.

What are the "yazane" chains?

By the hour tse buvaє as a result of a strong dvigun, rotten oil pump robots, brute olive canals, which go out from the hydraulic compensator line.

The most common reason is olive(vicariousness of inappropriate, detailed and unsuitable for your dvigun Olivi). The first thing that needs to be done is to pour the olive, to clean the dvigun, to use additives to resist the knock of the hydraulics and to go to your transport (vrahoyuchi probig).

All olivy pid hours of operation May building "Vigorati"(scientifically - aeration). Seals in the eyes of soot and those unacceptable are deposited on the parts of the engine, including all the middle of the hydraulic compensators, on the plunger pair and the bag valve.

This should be done before the driver stops working correctly, you can come I will not raise a cry. At this time valve does not close tightly, which can lead to a breakdown of the engine.

To prevent the knocking of hydraulic compensators in the most beautiful version, it will be necessary for your car to be clean, with the presence of powerful and anti-aeration additives.

The very same є canadian olive Petro-Canada. Its uniqueness in the patented technology of olive production HT Purity Process. There are many principles of insight from the traditional method of "cleaning by selective razchinniki" (which vikoristovuyutsya more vyrobnikiv olives). The main reason is the visibility of aromatic molecules, which reduce the exploitation of power.

Thus, instead of aromatic, the content of aromatic z "adnan" in olives:

(chim less - tim more beautiful)

Zvychaynykh (otrimanih by the method of selective cleaning = 10-35%
Petro-Canada (HT Purity Process) = less than 0.1%.

WHAT YOU GIVE YOU?

Petro-Canada is perfect for a drive in the middle
More beautifully grasping details from corrosion and oxidation
Roshid Olivie the lesser ;-)

І is especially important- use a stable medium for additives
(middle grating modifier based on 3-nuclear molybdenum)!

Olivia's warehouse including additive package, which allows you to put down a knock and cross the front end of the line of hydraulic compensators.

Vikoristovuchi Olivi Petro-Canada, you can get on with it, your dvigun will serve you for more rock, and the guides will stop knocking.

For the confirmation of the foregoing, it is suggestive VIDGUKI shoppers about results victoriannia olives Petro-Canada in the official online store shop.petro-canada.com.ua:

After reading positive reviews about the oil, I decided to try the RS supreme 5w30 in Kia cerate, while I like it, the knock of the hydraulic lifters on the cold one left, I thought it was already impossible to defeat them)))
PC Supreme 5w-30

I have been filling this oil for the 3rd year already, the Hyundai Accent MC 1.4 car gasoline, I change it 2 times a year before the fall and spring, the average mileage from replacement to replacement is 6-9k km, which I can say I really like the oil, the engine runs quietly, the oil does not eats, gas mileage with a quiet ride is 6.8-7.5 l / 100km. When draining, it has a characteristic dark color - it does its job of caring for the engine 100%. Thank you for a good product, I would like to buy it a little cheaper;) PC Supreme Synthetic 5w-30

I have been using the W8 FSI engine for many years. Everything is fine, the oil washes well and does not burn like castrol recommended by WAG PC Synthetic 5w-40

Already several times I fill in semi-synthetics PC Supreme (5W-30 for winter and 10W-40 for summer). Car - Chrysler Voyager 1992, 3.3 liters, mileage -350,000 km, car - on gas. The oil is excellent. Engine sound - satisfied rumbling. Gidriki stopped knocking. Starts up without problems in winter. I change it after 10,000 run, the oil is of course darkening seriously, but in principle it still looks very good (I looked at the skylight). No burning smell, etc.
I also doubted at first, was it the original? I read personal studies of car owners on different oil manufacturers (there is such a site. I don't know if I can mention it here, so I don't write) and chose PC. I relied on the decency of the store.
In general, I was pleased with the oil and the store. Buying is convenient. Arrived quickly. Works good. PC Supreme 10w-40

The operation of an internal combustion engine is necessarily associated with the release of heat. As you know from a physics course, when heat interacts with a metal, it expands. Motor designers take this fact into account in their design and provide thermal clearances. When calculating thermal clearances, special attention is paid to the valve mechanism of the car, where an error can lead to burnout of the valve or the appearance of knocking in the engine.

To allow auto shops and drivers to control the clearance, the engine valve train has the ability to adjust it. It is required to perform it during the operation of the machine, since worn parts lead to a change in the gap.

Initially, the clearance was adjusted using washers and levers, which was extremely inconvenient, and for the end motorist it was also too difficult. Over time, the designers have proposed a more modern solution - the use of hydraulic lifters. These mechanisms independently choose the required clearance and do not need additional settings. But problems can arise with them, and the most famous of them is the appearance of a knock during engine operation.

What are hydraulic lifters

An automobile hydraulic lifter is a piston with a bottom of the camshaft cam. The piston contains a ball valve, the task of which is to open the flap for oil to enter the piston cavity. The plunger is responsible for transferring force from the camshaft cam to the valve stem.

During operation, oil enters the piston. It fills the free space, after which it begins to press on the plunger. This leads to its movement together with the piston upwards until the mechanism rests against the camshaft cam. Thus, it is possible to achieve automatic selection of the optimal clearance due to the hydraulic compensator mechanism. When the cam of the camshaft presses on the piston of the hydraulic compensator, some of the oil is poured out of it, after which the ball valve blocks the path of the oil, the piston goes down and a gap is created.

The hydraulic compensator, unlike washers and levers, does not require additional adjustment when engine parts are worn. The gap is in any case regulated, due to the flow of more oil into the hydraulic compensator.

Why is the hydraulic lifter knocking?

The malfunction of the hydraulic lifter is easy to identify. If there are problems with this element, it starts knocking during operation. The consequence of the knock of the hydraulic lifter is an incorrect or untimely adjustment of the valve clearance, which can lead to problems with the engine.

It is possible to classify the reasons due to which the engine hydraulic compensator knocks, according to the conditions of their occurrence. Depending on whether the hydraulic lifters knock on a cold or warm engine, there are different malfunctions that can cause the problem.

Hydraulic lifters knock on a cold engine

Problems with the operation of hydraulic lifters can arise in two cases: when the mechanism itself is malfunctioning or because of problems in the oil supply system. On a cold engine, the following main reasons can be distinguished why hydraulic lifters knock:

Important: It is necessary to distinguish between the knock of hydraulic lifters on a cold engine and when starting the engine. Many drivers are mistaken in believing that if a characteristic sound is heard when starting the engine, there are problems with the hydraulic lifters. Knocking can occur and subside quickly as some of the valves continue to open (given the location of the camshaft) after stopping the engine.

Hydraulic lifters knock on a hot engine

The causes of knocking hydraulic lifters on a hot engine partially repeat the malfunctions due to which this problem occurs on a cold engine. Here are the problems that are typical only for a warmed-up engine:

The situation when hydraulic lifters knock only on a hot engine is rare. Most often, the problem occurs, both on a cold and on a warm engine, and it is associated with poor oil, a dirty oil filter or damage to the hydraulic compensator.

How to identify a knocking hydraulic lifter

Since there are several hydraulic lifters installed in the engine, it is necessary to determine which of them knocks during operation before replacing or detailed diagnostics. In service centers, the search for a faulty mechanism is carried out using a special device for measuring the noise level. Acoustic diagnostics is an effective method when searching for a problematic hydraulic compensator.

You can also diagnose the hydraulic lifter on a disassembled engine. To check them, you will need to remove the valve cover, and then make an effort to push each element separately. Hydraulic lifters, which, when exposed to external influences, will easily be recessed, have insufficient oil pressure, which indicates their malfunction. A jammed hydraulic compensator cannot be drowned by human forces.

Important: Pay attention that during the diagnosis the hydraulic lifters are not pressed by the camshaft cam.

What does the malfunction of hydraulic lifters lead to?

Problems with hydraulic lifters do not have a strong effect on the wear of other engine components, but the problem should not be postponed. It is necessary to search for the malfunction of the hydraulic compensator, since problems that arise may indicate a malfunction of the lubrication system.

By themselves, faulty hydraulic lifters will lead to a decrease in engine power, a deterioration in the dynamics of vehicle acceleration and an increase in gasoline consumption.

What to do if hydraulic lifters knock

In most cases, the clatter of hydraulic lifters is associated with problems in the lubrication system, which are caused by poor oil. Therefore, if there are extraneous sounds from the hydraulic lifters on a cold or hot engine, the first thing to do is to change the oil and oil filter.

Please note: The first start of the engine after changing the oil will again be accompanied by knocking of hydraulic lifters. This is due to the fact that after draining the old oil, the hydraulic lifters become "empty".

If changing the oil did not help fix the problem, it is necessary to determine which hydraulic compensator knocks during operation. Having identified a faulty element, you can remove it from the engine and try to rinse it in gasoline or kerosene, and then put it back in place. This will help if the cause of the knocking lies in the contamination of the hydraulic lifter.

Important: It is necessary to install hydraulic lifters after flushing in the position where they stood before removal.

When flushing the hydraulic lifters does not help to solve the problem with the occurrence of knocking in them, the elements will need to be replaced.