Flushing hydraulic lifters: procedure. Knock of hydraulic lifters on cold

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

Do-it-yourself car repair in most cases allows not only to save a lot, but also to prevent serious malfunctions in a timely manner. In vehicles equipped with 16-valve cylinder heads, hydraulic lifters may knock. It is possible to correct the situation. Flushing hydraulic lifters will help. Let's see how it's done.

Hydraulic lifters: what is it and where are they located

These elements are an important part of the gas distribution mechanism. You can find these hydraulic lifters directly above the valve. To be more precise, under the camshaft cam.

This part looks like a cylinder. Inside it is a special check valve, a plunger pair, as well as a spring. Special channels are made in the walls of the hydraulic compensator. They serve to circulate the oil.

Function of hydraulic lifters in the engine

During the operation of the car engine, every part of itheated to high temperatures. The valves also get hot. If we recall the course of physics, then at the moment of heating the body expands. This means that the gaps between the valves and rocker arms in the valve mechanism will inevitably decrease.

On older models of cars with engines of a simple design, valve clearances were adjusted manually. This is a simple job, but it requires certain skills, knowledge and a set of tools to complete it. If the gaps are adjusted incorrectly or at the wrong time, certain problems will appear. One of them is a knock, which is familiar to every owner of such a car. This noise indicates that the gaps are too large.

Small gaps also led to certain problems. Because of this, the valve did not close tightly. It was necessary to adjust the mechanisms quite often, as the settings constantly went astray during the operation of the motor.

Due to the introduction of hydraulic lifters, the car owner no longer needs to adjust valve clearances. Now this is done automatically. In other words, the presence of hydraulic compensators in the design of the motor greatly simplifies the process of servicing the engine, increases the resource of the valve mechanism, and provides the motor with more elastic and stable operation.

Signs of a malfunctioning hydraulic lifter

One of the characteristic symptoms is a metallic knock during engine operation. These noises can be heard especially clearly at the moment of revving. A clatter will be heard. The most common cause is pollutionhydraulic compensator from the inside. Therefore, it cannot select thermal gaps in a timely manner.

Cold sound

You can also hear the knock of the hydraulic compensator when cold. After the engine warms up, the sound disappears. But it can also be saved. If these sounds occur only on a cold engine, then this is not so scary. There are several reasons that are completely fixable with your own hands.

Wrong choice of oil

Noises on a cold engine can happen for banal reasons - a higher viscosity oil is poured into the engine. Sometimes it does not meet the requirements of the manufacturer or has exhausted its resource.

When buying a car "from hand", it is recommended to change the oil immediately to a new one. Also, before replacing, you need to flush the engine from the inside. This is done simply with your own hands in a garage environment. Experts recommend pouring semi-synthetic fluids. If the oil has been changed, but the tapping of the hydraulic lifter when cold is still audible, there are other reasons to consider.

Valves

Sometimes hydraulic compensator valves can fail. In this case, oil will leak out when the engine is not running due to loose connections. Air will enter the system, which then disappears when oxygen is displaced by the oil.

Inlet port

It happens that the inlet on the hydraulic lifter becomes clogged. The hole is responsible for supplying oil to the part. When the engine heats up, the temperature of the oil also increases. The gaps expand, and the oil begins to flow as expected. Howevervarious viscous elements then clog the inlet again. You can change the oil to one with a lower viscosity. Cleaning the engine will also help. Along with these measures, flushing the hydraulic compensator is also effective.

Oil filter

If this element has not changed for a long time, then this is also one of the reasons why the hydraulic compensator will knock on a cold engine. Together with the heating of the engine and oil, it will begin to flow normally through the filter. But more often than not, this doesn't happen. Elements knock even on a warm engine. Changing the oil along with the filter will help solve the problem.

How to check the performance of hydraulic lifters

And how to check hydraulic lifters at VAZ? By dismantling the valve cover, you can access these elements. Next, each of them is pressed with a finger. If a part fails, it will sink without effort.

In this situation, the element cannot be restored. Only replacement will help. How much it costs to replace hydraulic lifters depends on the car model and engine. So, for most VAZ models, this operation will cost five thousand rubles. If imported parts are selected, then the price will be 7-10 thousand. Naturally, this is not an exact cost - specific figures depend on the region and car brand. If the mechanism is recessed only from a serious effort, then flushing the hydraulic lifters will help restore performance and remove the knock.

Preparing for flushing

So, if there is a knock, but the main drives are in good order, then you shouldrinse them. To do this, remove the air filter and the cylinder block cover. They also dismantle the axles of the rocker arms, where the hydraulic lifters are located. They are carefully removed from their seats. Before rinsing, three containers are prepared, which together have a volume of about five liters.

Before flushing, you should let the car stand in the garage for a day. During this time, the oil will drain from the HA into the sump. Flushing hydraulic lifters will be successful and effective if performed indoors, where there is no dust and wind. Kerosene or A-92 gasoline can be used as a flushing liquid. But specialized products can also be used.

Instruction, procedure

After dismantling the compensators, they are cleaned from the outside with brushes with artificial bristles. Then the parts are washed in the first container, where the liquid for washing the hydraulic compensators is pre-filled. Each element is lowered into the container and the check ball valve is pressed several times with a wire. Then they press on the plunger.

If the plunger stroke has become easy, then the compensator is washed in the second container. However, before that, all liquid is drained from the compensator. To do this, just squeeze the ball. The oil circulation channels are flushed using a syringe.

An important point in this operation is to check the mechanisms. So, having lowered the compensator into the third container with a cleaning agent, they draw liquid into the part.

Then lower the part and pull it out so thatthe plunger looked up. If you press on it with your finger, it will not move. When everything is just right, the parts are returned to their place and the engine is assembled.

With the help of such a simple procedure, you can return the hydraulic lifters to working capacity. Even an expensive Liqui Moly hydraulic lifter flushing additive will not cost more than replacing these elements with new ones.

How to flush hydraulic lifters without removing them

For those who are too lazy to remove the HA, you can flush without dismantling. So, for this, the intake manifold is dismantled. Then they take any liquid for decoking and pour it into each of the cylinders. Next, the motor is turned by the starter. Then the cover is removed and the compensators are poured over with a carburetor cleaner. It is better to choose a liquid good and expensive. Then leave the car untouched for a couple of hours.

Then everything is assembled in the reverse order. When starting the engine, it is recommended to press the gas to the floor. Smoke will come out of the exhaust pipe and various debris will fly out. Gain high speed and hold until the moment when the smoke from the exhaust pipe stops coming out. It is recommended to drive at high speeds for a while. Such flushing of hydraulic lifters without disassembly is very widely used by car owners. However, it is not as effective as with withdrawal.

GK Flush Additives and Fluids

According to most experienced motorists, only A92 gasoline should be used as the best flushing agent. Kerosene is also good. Along with these folk remedies, eminent auto chemical manufacturers offer brandedfluids and additives. It must be said that most of these products are ineffective. But many pour them because they know well how much it costs to replace hydraulic lifters. Lots of information is available about Liqui Moly's product to reduce hydraulic lifter knock.

The manufacturer promises that with this additive you can clean not only the compensators themselves on any car, but also the valve holes. The additive also improves the lubricating qualities of motor oils. If necessary, the liquid can also be used as a cleaning agent for the entire lubrication system.

If, for example, the Niva-Chevrolet hydraulic compensator knocks due to contamination, then this product copes well with this problem. Reviews of motorists note that it is not even necessary to drain the oil. It is enough to pour one bottle of this product into the filler neck. In other cases, additives will not help - this is not a cure for all diseases. But the manufacturer still recommends filling in the additive at each oil change.

After flushing, the same Niva-Chevrolet hydraulic compensator stops knocking after 50 kilometers of the car. Considering how much a new element costs, the price of flushing 400 rubles is a significant savings. But in the reviews it is noted that this is not always effective. In advanced cases, it is necessary to change the entire hydraulic compensators.