Knocking hydraulic lifters

The hydraulic compensator (another name for the hydraulic pusher) performs the functions of automatically adjusting the thermal clearances of the car's internal combustion engine valves. However, as many drivers know, for some reason it starts to tap. And in different conditions - both cold and hot. This article describes why hydraulic lifters knock and what to do about it.

How it works and why the hydraulic compensator knocks

Why do hydraulic lifters knock

Hydraulic lifters tap for a variety of reasons. usually, this is due to problems with the oil or oil system, the hydraulics of the internal combustion engine, and so on. Moreover, the reasons differ significantly depending on the state of the internal combustion engine - hot or cold.

Hydraulic lifters knock on hot

We list briefly the most common causes of the knock of hydraulic lifters on hot and what to do with it:

• Haven't had an oil change in a while or it is of poor quality.What to produce - In order to avoid such problems, you need to change the oil.
• Valves clogged. At the same time, the uniqueness of the situation lies in the fact that this problem can only be detected with a hot internal combustion engine. That is, with a cold engine, there may or may not be a knock.What to produce — flush the system, and also replace the lubricant, preferably with a more viscous one.
• Clogged oil filter. As a result, the oil does not reach the hydraulic lifters under the required pressure. Therefore, an air lock is formed, which is the cause of the problem.What to produce — replace oil filter.
• Oil level mismatch. It can be either its lowered or elevated level. The result is excessive saturation of the oil with air. And when the oil is supersaturated with the air mixture, a corresponding knock occurs.
  

  How to check the hydraulic lifter

  What to produce - the solution to this problem is oil level normalization.

• Incorrect operation of the oil pump. If it does not work at full capacity, then this may be the natural cause of the indicated problem. What to produce - check and adjust oil pump.
• Increased hydraulic compensator landing site. In the process of heating the internal combustion engine, its volume also increases more, which is the cause of the knock. What to produce - for help contact a mechanic.
• Problems with mechanics and hydraulics. What to produce - there can be many reasons, therefore we recommend contacting a specialist.

Hydraulic lifters knock on cold

Now we list the list of possible reasons why hydraulic lifters knock on a cold internal combustion engine and what to do with it:

• Failure of the hydraulic compensator. However, a similar knock is also characteristic of a hot internal combustion engine. The cause of the breakage of the hydraulic compensator can be mechanical damage to the elements of the plunger pair, its wedge due to the ingress of dirt inside the mechanism, malfunction of the oil supply valve, mechanical wear of the external mating surfaces. What to produce – to perform diagnostics and make decisions better consult a specialist.
• Increased oil viscositythat has exhausted its resource.What to produce - the solution to the problem will be Change of oil.
• Doesn't hold hydraulic valve. As a result, there is an outflow of oil when the internal combustion engine is muffled. In parallel with this, the process of airing the HA occurs. However, this effect disappears when air is replaced with oil.What to produce — bleed the hydraulic compensator, change the valve.
• Inlet hole clogged. This is the oil inlet. In the process of heating the internal combustion engine, a natural process of dilution of the lubricant occurs, which enters through the corresponding hole.What to produce — clean the hole.
• Temperature mismatch. Some brands of oil are not suitable for operation at low temperatures. That is, its consistency does not correspond to the operating conditions.
  

  How to disassemble, clean or repair a hydraulic lifter

  What to produce — fill in the appropriate oil, which is able to maintain its characteristics even at significant frosty temperatures.

• Does not hold the hydraulic compensator valve, while oil flows back through the valve, and the HA is aired. During the shutdown, the internal combustion engine cools down, after which the lubricant also changes its physical properties. Accordingly, until the internal combustion engine warms up, oil will not begin to flow into the system. What to produce — replace the valve or hydraulic compensator.
• Clogged oil filter. Everything is simple and obvious here.What to produce — replace filter.

What oil to pour if hydraulic lifters knock

Before choosing an oil, you need to determine exactly when the hydraulics knock. Very often a knock is heard immediately after the start, so you need to establish which oil to fill in if the hydraulic lifters knock on a cold. This is a common problem, especially for owners of the VAZ 2110, Priora and Kalina.

Follow the rule - if the hydraulics knock on the cold, then you need to fill in more liquid oil. For example, if your car was filled with 10W40 oil, then to eliminate the knock, you need to change it to 5W40. You can also try to fill in the brand 5W30.

For those who do not know what oil to fill in if the hydraulic lifters are knocking on hot, then you can try to fill in the additive. This is often done if the knock from the hydraulics is heard all the time. In 80% of all cases, the use of only one Liqui Moly Hydro-Stossel-Additiv additive can solve the problem.

But if this does not help, you need to replace the oil with a more liquid one, choosing another manufacturer. It is important to choose the optimal viscosity (this is often 5W40). If too thin oil is used in the internal combustion engine, the pressure in the system will drop and the hydraulic lifters will not be completely filled with oil.

If they knock new hydraulic lifters, then it is easier to decide which oil to pour. you need to fill in new semi-synthetic oil. For example, if you have 5W40 synthetic oil on Priora, then you can choose the same viscosity, but semi-synthetics.

Do not worry if hydraulic lifters knock at idle. When starting an internal combustion engine, this phenomenon is most often temporary, and this is due to the viscosity of the oil. As soon as the oil warms up to operating temperature, the knock disappears. If a knock is heard at idle any time, then this indicates the need to change the oil to a more liquid one.

When constantly knocking hydraulic lifters, then it’s better not to use any additives or solve the problem by changing the oil - you need to check the hydraulic lifters, because often a constant knock indicates the failure of several hydraulics at once or there are a lot of resinous deposits in the motor and in order for the parts to receive proper lubrication, you need to flush the oil system.

Why are the new hydraulic lifters knocking?

Dirty oil channels

Tapping new hydraulic lifters at first is normal. But if the knocking does not subside soon, then you need to look for a problem. Considering that such hydraulic lifters did not give in to wear, it is unlikely that they are the reason. But it is desirable that when buying a new set of compensators, you would be given a guarantee. So you save money in case of marriage or an unsuitable version of the mentioned compensators.

Incorrect installation, and as a result, there is no supply of lubricant, which is why hydraulic lifters knock. Other possible problems are also determined by the fact that compensators are not pumped - oil does not reach them. Clogged oil channels, a faulty oil pump, and the like can be guilty of this.

How to determine that hydraulic lifters are knocking

How hydraulic lifters knock

There is an easy way to understand that hydraulic lifters are knocking. Their knock is sharp and does not coincide with the operation of the motor. The characteristic “chirp” has a frequency exactly half that. These are peculiar ringing clicks that are heard from above the internal combustion engine.

It often happens that the sound of hydraulics is almost inaudible from the cabin. This is the main difference between the malfunctioning of hydraulic lifters and breakdowns of other engine elements.

Video on how to accurately determine what the hydraulic lifters are knocking on:

How to identify a faulty hydraulic lifter

It is not difficult for a mechanic to identify a faulty hydraulic compensator. Remove the terminals from each candle in turn, so you will understand where the faulty hydraulics are located. After that, you need to press on them. According to a large number of reputable experts, faulty compensators, even under slight pressure, simply “fail”. Therefore, finding faulty elements among them is quite simple. The one that "failed" is worthless. Accordingly, which did not “fail” is suitable.

Is it possible to drive with knocking hydraulic lifters

Many drivers are interested in the question of whether it is possible to drive with knocking hydraulic lifters and what consequences this can lead to. Let's answer it right now - possible, but undesirable, since the machine will pursue a number of problems. namely:

• loss of power;
• loss of control elasticity (the car will respond worse to steering);
• unenvironmental (unhealthy rear exhaust plume);
• excessive fuel consumption may occur;
• increased vibration;
• additional noise under the hood.

Accordingly, during the operation of a faulty internal combustion engine, there is a chance to “finish off” it completely. Therefore, it is categorically not recommended to drive with faulty internal combustion engine elements. After all, sooner or later it will fail. And the sooner you start repair work, the cheaper and easier they will cost you.