Knock of hydraulic compensators Niva Chevrolet

Description of the hydraulic compensator device and its principle of operation

Hydraulic compensators are designed to automatically regulate the thermal gap between the valves and the engine camshaft. The hydraulic attachment is provided by oil, which enters the expansion joints under pressure, and a complex and incredibly precise set of springs provides the necessary clearance.

Hydraulic compensators, which have been installed on Chevrolet Niva in recent years, give them a tangible advantage:

there is no need to periodically adjust the valves;
now the timing belt works more clearly and correctly;
The noise when the engine is running has decreased significantly; it begins to knock less;
The service life of timing parts has increased significantly.

Main details of the unit:

Plunger pair.
Frame.
Plunger bushing.
Plunger spring.
Plunger ball valve.

The operating principle of the unit is relatively simple and consists of three main functions:

There remains a small gap between the camshaft cam and the compensator, which is filled with oil. The plunger spring pushes the plunger out of the sleeve, the oil fills the gap under pressure, reaches the desired level, and the ball valve shuts off the oil supply. After these actions, the gap disappears.
By turning, the cam moves the compensator down. Due to the accumulated oil, the plunger pair becomes rigid and presses on the valve, opening it.
As the plunger moves down, it loses some oil and its pressure drops. As the cam moves further, the cycle repeats.

Types of hydraulic compensators

At the beginning of the production of Chevrolet Niva cars, old-style compensators were installed, and in the fall of 2008, a modified, new version of this part began to be installed.

Hydraulic compensators Niva Chevrolet old model

Until 2005, General Motors supplied its own expansion joints, which were of impeccable quality. But then the domestic “hydriki” came along, and the problems began. The quality of the supplied parts left much to be desired; the metal from which the parts were made was raw and did not have a long service life.

New Generation

The end of 2008 was marked by the appearance of a new generation of hydraulic compensators among Chevrolet Niva assemblers. At first, about two years, there were no problems, the parts were of good quality, the metal was hardened and wear-resistant. And then the same story began as with the old ones - the glasses became “half-baked” and could not serve their owners for a long time.

Depending on the design of the timing mechanism (gas distribution mechanism), several types of hydraulic compensators are distinguished:

hydraulic pushers;
roller hydraulic pushers;
hydraulic supports;
hydraulic supports, which are installed in rocker arms or levers.

How to identify a faulty hydraulic compensator

To determine a knocking compensator, you need to use a screwdriver, which is used as a lever, to press on those “hydraulics” that are at TDC (top dead center). If the hydraulic compensator fails under pressure from a screwdriver, it means it is not adjusted. If you want to make sure of this, quickly press with a screwdriver and you will hear a characteristic sound.

Typical faults

Problems with hydraulic compensators arise for two reasons. It is not difficult to identify them - this is either a mechanical breakdown of the unit itself, its destruction, or a breakdown of the oil supply system to the compensator.

In the first case, a common cause is wear of the plunger pair. This is an inevitable process that depends only on the operating time of the unit and the quality of the metal from which it is made. Factory defects cannot be ruled out; this is extremely rare, but it does happen. Replacing this part costs the same as replacing a regular consumable.

In the second case, the oil level in the engine matters; it can be too low or too high. The oil filter may be dirty and dirt may have entered the channels. Untimely oil change is another reason for unstable operation of the unit.

Do not forget about the correct selection of oil - use oils of the same type and preferably from the same manufacturer. The consequences of failure to comply with these rules can be disastrous; saving on oil can cost you money to repair the engine.

Why are they knocking?

It's easy enough to hear. The knocking of hydraulic compensators on a cold or hot engine begins to appear directly during engine operation and has a direct impact on the stability of its operation.

The reasons that the element is knocking “hot” are as follows:

The oil pump has failed. The system does not create the required pressure.
The hydraulics of the hydraulic compensator are broken, that is, the system does not have the required amount of oil or, conversely, there is an excess of it.
The landing site of the part has increased significantly due to the heating of the engine, during which the metals expand.

These causes of malfunction are typical only for a warm engine. It is worth noting that the sound of these elements on a hot engine is quite rare.

Most often, the hydraulic compensator knocks “when cold”, and for both modes the sound may appear due to low quality oil. It also occurs due to a contaminated lubricant purification system.

Causes of knocking hydraulic compensators

The knocking sound of Chevrolet Niva hydraulic compensators can be easily detected by ear; it knocks at a frequency half the engine speed. It can knock both on a cold engine and on a hot one, and the reasons for this are different.

Reasons for knocking when cold:

Thick oil. As the engine warms up, the oil heats up, becomes thinner, and the knocking noise goes away.
Dirt. A bad filter or old oil can cause dirt to get into the channels and holes and clog them.
Worn or broken plunger. The cause may be natural wear or abrasive contaminants that have entered the oil.

"Hot":

Plunger jamming. Scuffing on the plunger pair increases its wear significantly and blocks it.
Oil with incorrect viscosity. When changing the oil seasonally on their own, sometimes owners make mistakes and fill in oil with the wrong viscosity. If it is too liquid, it quickly flows out through those. gaps.
Increased oil level in the engine. If this is due to coolant getting into the oil, it will foam in contact with the crankshaft.

All these reasons can be eliminated yourself if you carefully monitor your car.

Causes and signs of failure of hydraulic compensators

It is important to determine when the main valves are knocking. Often, knocking occurs only when “cold” , and disappears within 30-45 seconds. The reason for this is a delay in the supply of oil to the hydraulics due to its insufficient heating. It’s another matter when the knocking of the hydraulic compensators occurs “hot” , then you will have to remove the camshaft and clean the channels. If flushing does not help, it is necessary to replace the Chevrolet Niva hydraulic compensators.

The main symptom, which usually manifests itself at 50,000 km, or even 40,000 km, is the appearance of distinct sounds in the camshaft area , and when you try to increase speed, a metallic crackling occurs. The reasons for this may be:

The pressure in the car's oil supply system has dropped, as a result of which an air plug has formed, preventing the oil from reaching the hydraulic fluid.
A clogged oil filter leads to clogging of the oil channels and a decrease in the flow to the hydraulic compensators.
Reduced or increased oil level in the system, which caused excessive saturation of the oil with the air mixture, which caused the characteristic knocking sound.
Worn seat for hydraulic compensator. As the engine operates, the temperature increases the seat even more.

When replacing the camshaft, it is necessary to take into account that the cause of knocks coming from the camshaft can also be:

deterioration of the camshaft cams;
wear of the rocker surface;
erasing the end of the valve stem.

Is it worth replacing hydraulic lifters with bolts on a Chevrolet Niva

What is more practical, a bolt or a hydraulic compensator - this question worries many Chevrolet Niva owners. First you need to find out why some drivers decide to make such a replacement? The answer is simple - the introduction of compensators gave hope to once and for all solve the issue with thermal gaps. In fact, the poor quality of hydraulic compensators only worsened the situation - more money was spent, but the problem was not solved.

For this reason, some Niva-Chevrolet owners “return to basics,” i.e., they switch back to bolts. One can argue a lot about the effectiveness of such a transition, but often on the forums of owners of such cars one can read the following reviews:

“...I changed the hydraulics back to bolts, the result: the consumption dropped, the idle speed was stable, the traction started from the bottom, the clutch became noticeably lighter. I’m happy with the decision, the replacement justified itself.”

Such statements are becoming more and more common. Many people do not dare to take such actions - owners are afraid to change something in the engine, so everyone makes this decision for themselves.

When it is necessary and when it is not necessary to change hydraulic compensators and replacement features

Ideally, during normal operation of the hydraulic compensator there should be no extraneous sounds. But sometimes you hear sounds from under the hood that make you want to replace timing parts. But hydraulic valves on engines with high mileage must be replaced - they have a high percentage of wear and tear and there is no point in repairing them. In other cases, you can get by with less radical actions.

Attention. Sometimes you shouldn’t immediately disassemble the engine and try to find out the cause of the breakdown. Often an oil change is enough for the problem to go away, and money and nerves are saved.

Among the features of replacing hydraulic compensators on a Chevrolet Niva, it is worth highlighting the following:

if you notice an extraneous knock from under the valve cover, do not rush to immediately disassemble the timing belt and change components; first change the oil and filter;
use oil from the same manufacturer;
there is no need to tighten the parts too much, this may lead to breakage;
When installing new parts, do not forget to rinse them thoroughly in gasoline.

Oil selection

In such a situation, many will think about what kind of oil to pour when the hydraulic compensators are knocking. The answer is quite simple: you need to fill in lubricant of the required viscosity, which is recommended for use by the manufacturer. Currently, in the summer, it is most popular to use semi-synthetics in cars, that is, 10W-40. In winter, you should use 5W-40.

After changing the oil and filter, you should not be sure that there will be no sound. Quite the opposite: the knocking sound of hydraulic compensators “when cold” will also be heard due to the fact that there is no lubricant left in the pistons after draining. However, after the engine warms up, it should disappear, thereby confirming the correctness of the replacement decision.

Recommendations

Comments 54

1. How to hear which main engine is knocking. A stethoscope, which is what I use (a small box with a metal rod and a capsule in the ear). If it is not there, then a wooden ruler in the teeth (but audibility is worse and you need to plug your ears). You can try it with a medical stethoscope with the appropriate attachment (I haven’t tried it, because there is no need) 2. What year is the car made? If up to 2008 inclusive, then the hydraulic locks are of the old type and they need to be tightened to a torque of up to 2.5 kgf, preferably 1.8-2 kgf, otherwise it will be worse than it was. And for this you need a torque wrench. Moreover, the entire operation of replacing the camshaft housing (except for the first one, it cannot be removed due to the tide on the camshaft housing) can be performed without removing the camshaft housing, just unscrew the nuts securing the housing and lift it as much as possible (as far as the chain will allow). To determine the tightening force, clamp the square of the dynamic key into a yew, and place a 27 wrench on top of it (if I’m not mistaken). The key will be shorter than the din. key. Take your hand at the place where the force is applied to the simple key and begin to “tighten” while holding both keys with your hand, looking at the readings of the dynamic key up to 2 kgf. This is how you determined the tightening force using a simple wrench. Well, go ahead. GKs cost approximately 250-350 rubles, do not forget to buy a pair of studs (long and short) in case the threads on the existing studs are bad. Tighten the camshaft housing according to the diagram and din. key, otherwise you will break the pins. Well, look at the supply line that was recommended in the posts above. There may actually be a crack or leak. I've done the same thing myself more than once. The result is 100%. I DO NOT recommend doing repairs without a torque wrench. Good luck. If you don’t understand anything, write and I’ll answer.

Thank you very much, but everything has already been changed! For those who will change the Civil Code, this information will really help!

I'm very glad that I helped in some way.

Why do you think that the compensators are knocking, maybe it’s a matter of the tensioner

The compinastors were whole, the workers turned out the rack had burst) they were all thrown out and plates were installed

Car 2003 The first set of hydraulics ran for 150,000, although the “pilot” set it to 80,000. Now the second set works without problems. Shell Helix Ultra oil after 15000. There is no desire to install bolts.

They knock the same thing when cold and I will only change it to a hydrocom and not toy soldiers

here is the specific link of the specialist niva-fr.ru/?page_ >

Everything has already been done) the conpinsators were thrown out and plates were installed instead. But thanks anyway)

Is it possible to replace the Hz with bolts yourself? who has info

We changed it ourselves without any specialists, etc., just take care of your nerves, it’s difficult to get there, but it’s still possible! I just called a friend at the end to adjust the gap; he had already adjusted it more than once, but you can do it yourself

I support normal synthetics and no problems with hydraulics. The knocking noise can only be due to oil starvation or a broken spring in the hydraulic valve; as a rule, it can be treated by disassembling and cleaning the compensator. In any case, it is worth replacing only a faulty one with a broken spring or obvious signs of wear and external defects in the form of cavities, etc.

I am for! hydraulics. So far everything is working fine for me! A knocking sound when cold may be due to oil. for them it is desirable ONLY SYNTHETICS! tap on the mineral and half-blue. there have already been discussions on the drive!

Take them away and drive on a simple head, there was an ambush with them, I suffered, changed them to a regular one and forgot about everything!

We hear a bell, but we don’t know where it is.

The owner of a VAZ-21214 complained about constant knocking in the engine. Sometimes they last a very long time, sometimes not so long, but most often they happen on a cold engine. While we were standing and talking, the knocking appeared again and the engine began to feel feverish. It seems as if he is “trotting.” The knocking continued for no more than a minute and then disappeared. The client left the car and left. We agreed with him that I would call myself when I fixed the problem.

Based on the nature of the knock, it was obvious that one of the eight hydraulic compensators was faulty. But which one!? I didn’t want to change everything, or the first one that came to hand, so I used the “First Look” sensor.

It doesn't have such a name for nothing. If we translate it literally into Russian, we get – “First Look”. So it is, the name speaks for itself! Being in the diagnostician's arsenal, it can always be used first to quickly identify a malfunction. The sensor is installed on the section of the exhaust pipe of the muffler. Based on the pressure pulsation in the exhaust system, the quality and uniformity of operation of the engine cylinders is analyzed, an ineffective or faulty cylinder is localized, and the quality of the mixture is determined (lean or rich).

Well, let's get started and see how it performs at work! The next morning, fully confident that I will detect a malfunction very quickly, I connect the “First Look” sensor to the MTS-5100 motor tester, select the “4-channel oscilloscope” mode, and insert the sensor into the exhaust pipe.

In parallel with the “First Look” sensor, I connected an electronic vacuum sensor to the receiver to identify possible malfunctions in the intake system. It was connected to the first channel of the MTS-5100 motor tester. For synchronization, I chose the second channel and connected the synchronization sensor to the high-voltage wire of the first spark plug.

Everything is ready for measurements. Unfortunately, I was unlucky that day. After starting, the engine ran perfectly, without any extraneous noise. I tried to start it many times, warmed it up, cooled it down, drove the car outside, warmed it up again, but as luck would have it, there was no knocking. This is how the first day ended... Then the second, then the third... On the fourth day, I drove this car home after work, tying the “First Look” sensor with electrical tape to the car’s bumper, and placing the tester motor on the front passenger seat. On the way, I monitored the oscillograms and was ready to press the STOP button at any second to record the signal. But neither on the way home, nor on the way back to work in the morning there were no knocks, the engine worked perfectly. No luck again. And so every day - connecting and removing the motor tester and sensors several times. Only at the end of the week was it possible to record several oscillograms of the idle speed while the knocking lasted for 8-10 seconds. But I didn’t have enough time; I needed to look at the oscillograms at high speeds. And finally I got lucky! After the next morning engine start, one of the hydraulic compensators knocked distinctly and knocked for a long time, about 5 minutes, then died down. This time was enough for me to fully diagnose the engine in different operating modes. At XX we see rare engine failures on the first and/or second cylinder.

They are almost always present in the third and fourth cylinders, at any engine speed.

From these oscillograms I conclude that the exhaust valve of the third cylinder is knocking and there is some kind of malfunction in the exhaust valve of the 4th cylinder. I'll see what happened to the first and second after removing the valve cover. Now let’s look at the vacuum sensor channel on the motor tester, i.e. first ray The oscillogram shows “humps” of different heights during the intake stroke. The smallest corresponds to the third cylinder.

So, I have previously determined the malfunctions of the exhaust valves of the 3rd and 4th cylinders and the intake valve of the 3rd cylinder. I remove the valve cover. At first glance everything is fine. I turn the crankshaft and check the tightness of the hydraulic compensators. The sixth in a row, that is, the intake of the 3rd cylinder, spontaneously turned out one revolution. Valves 1, 2, 4, 7 were loosely tightened. This caused rare interruptions in all other cylinders. The eighth one had a crack in the oil supply line. I didn’t notice it right away, but the experience of the previous repair, on which the article above was written, helped.

There was also a third malfunction in this engine - the stabilizer mounting bolts had come loose and it was dangling freely.

The line, the hydraulic compensators of the 3rd cylinder were replaced, the damper bolts were tightened. Reassembled everything in reverse order. All that remains is to check the operation of the engine and take a control oscillogram.

The engine started without any extraneous noise and, as we can see, everything is OK on the oscillogram!