Hydraulic valve clearance compensators do all the dirty work for us to adjust the clearance between the valve and the camshaft (pusher, rocker). Nevertheless, with a careless attitude to the engine, the clatter of hydraulic lifters can spoil the mood and throw up problems. Is it possible to ride knocking pushers, how to get rid of knocking and what to do to increase the resource, repair or buy hydraulic lifters, we will consider these subtleties right now.
Hydraulic lifters knock. Causes and consequences
Clacking, clanking, tapping pushers are only the first signal that something is wrong with the engine. The clatter of the hydraulic lifter is like a litmus test of the state of the lubrication system, and of the entire engine. Visually, we cannot judge the degree of oil wear or the cleanliness of the oil channels. Instruments on the panel will not say anything either - the pressure and level are in order, then everything is fine. is a finely tuned plunger device that will respond to any negative changes in the lubrication system.
The clatter of the hydraulic lifter may indicate other problems in the engine.
Is it possible to drive with faulty hydraulic lifters
Highly undesirable. We understand that the knock of the hydraulics speaks of the incorrect operation of the gas distribution mechanism. This means that the valve timing is not configured as expected.
Riding with the clatter of hydraulic lifters will undoubtedly give:
- high fuel consumption;
- severe loss of power;
- overheating of the engine is possible;
- if tightened with repair, the valves or the piston crown will easily burn out.
In a word, when a knock appears, it is advisable to carry out diagnostics and repairs as soon as possible.
Burnt valve - a consequence of knocking hydraulic lifters
Hydraulic lifters knock on a cold engine
The knock of hydraulics on a warm and cold engine can indicate various malfunctions and problems. However, there are no such troubles that could not be corrected. Cold water pushers can clatter for a number of simple reasons:
Knock of hydraulic lifters on a hot engine
New hydraulic lifter knocks
It happens that after a complete replacement of the hydraulics, a knock will be heard at the first engine starts. This is quite normal, since the pushers need to get used to it. Nevertheless, the knock should disappear after 100-200 km of run. If the new wetsuits keep rattling, it’s not their fault. That is why it is very important to be able to buy hydraulic lifters with a guarantee, and from a reliable seller.
If installed incorrectly, a new hydraulic lifter may also knock. In addition, the knock of new hydraulic lifters, just purchased, may be caused by their incorrect installation. For example, we made a mistake and did not sink the hydric completely into the well, the oil channel of the block head did not coincide with the inlet of the compensator, as a result, oil did not get into the body, the compensator cannot physically work. As an option, when the new expansion joints knock, the oil channels are clogged, the oil does not get access to the hydraulics.
Diagnostics. How to find a faulty hydraulic lifter, how to check
Checking the hydraulic gap with a feeler gauge To diagnose a hydraulic compensator, you do not need to go to a service station and pay extra money. The signs of its malfunction are so obvious that we will determine them ourselves. Before checking the hydraulic compensator, we will find a dipstick or a set of dipsticks 0.01-0.5 mm thick. Remove the valve cover and find any open timing valve - the camshaft cam should point up. Insert the dipstick between the lower part of the cam and the hydric, if the gap is greater than 0.1 mm , the compensator does not work, it needs to be pumped, repaired or changed.
Checking the hydraulic compensator by punching
More precisely, you can check the hydraulic lifter removed from the head. If we manage to push the wetsuit with our hands, it will fall through and squeeze out, the malfunction is obvious. In this case, we will change the compensator or try to restore it, it all depends on
Before starting to study the list of reasons why knocks can be heard, we will find out what hydraulic lifters are and how they work.
A hydraulic compensator, also known as a hydraulic pusher, is a part that allows, due to oil pressure, to automatically adjust the clearances between the camshaft and valves. The principle of operation is that when the cam of the camshaft acts on the piston of the hydraulic compensator through the plunger pair, due to this, part of the oil is poured out and the ball valve shuts off the oil supply, creating the required pressure. Then the piston is lowered and due to the internal oil pressure in the hydraulic compensator, the ball valve is pulled to the required "depth" to the shaft cam, thereby automatically adjusting the required clearance for the valve and shaft.
Where are the hydraulic lifters located
Why do hydraulic lifters knock?
So, here are the most common reasons. In general, all causes can be grouped into two groups of malfunctions:
1. Malfunctions directly with the hydraulic compensator mechanism itself.
2. Malfunction in the oil injection system and fluid quality.
We will classify the reasons depending on the knock that occurs when the engine is hot or cold.
Knock on cold:
Dirty oil. Oil clogged with shavings, fumes, carbon deposits and other debris can cause knocking on a cold engine. This debris clogs the oil-conducting channels. There is no such problem, on a warm engine, when the hot oil washes away all the debris.
Dirty oil under the oil filler neck
Contamination of the mechanism itself. As you know, a plunger mechanism is installed in the hydraulic compensator, which is responsible for extending the ball valve. So if the seat is dirty, it can simply jam.
Wear of mechanisms. From the article earlier, you should have understood its structure and work. Accordingly, in the event of damage to the plunger or seat, the oil will not be retained in the so-called sub-plunger space.
Jamming of the plunger pair or the main gas valve due to carbon deposits, mechanical damage, and the like. Only full diagnostics will help here, possibly with the purchase of a new part.
Wrong oil selected. Too oil until the engine is fully warmed up, it just does not have time to get into the hydraulic lifters. The problem is especially acute in winter, when many simply choose the wrong type of oil and is too viscous, they simply do not have time to get to the GC.
Pollution. Similar to the previous problem, when oil does not flow. Here, too, in the case of severe filter contamination, an insufficient volume of fluid will flow into the cylinder head.
Leaking GK valve, due to which the required pressure in the system is not created.
Another reason, which is no less common, concerns the low oil level in the internal combustion engine. In the experience of many owners, control the amount of oil. Try to stick to the average or slightly above average, then there will be no problems. By the way, this problem is easily diagnosed. In this case, the knock is heard only at "idle", immediately after starting the internal combustion engine.
As you can see, the main block of reasons is the problem with the oil system. There is bad oil, clogged passageways and the like. Therefore, first of all, change the oil and filter, then, perhaps, the knocking will disappear. But, keep in mind that immediately after starting with a new liquid, the knocking will continue for some time. Since after draining the oil, the hydraulic lifters will be empty and it takes time to pump a new portion and drive it all through the filter for cleaning.
With mechanical damage, it is clear that you need to go to the service and there it is already determined whether it should be restored or replaced. In some cases, it is possible, for example, to grind the burrs so that the sub-plunger space remains sealed. If carbon deposits simply formed on the hydraulic compensator, then it is enough to clean it. But, be careful not to leave scratches, dents and the like. Better consult a specialist.
Knock on the hot
The reasons for knocking on a hot one may coincide with those listed above on a cold engine.
Excess or vice versa lack of oil in the system. Because of this, by the way, too much air accumulates in the system. Therefore, when more oxygen is compressed, a knocking sound may be heard. This problem does not occur on a cold engine, because air enrichment occurs only when the oil is heated.
The seat of the hydraulic lifters increases. And taking into account the overheating of the motor, the metal expands, the knocking may increase.
Hydraulic lifters in the Lada Priora engine
Insufficient oil pressure. Defective oil pump or contamination in the system, contaminated filter.
Poor quality or incorrectly selected oil. Change as soon as possible.
Mechanical damage to the main body, plunger pair, valve, for example, seizures, scratches, etc.
As you can see, in both cases, the reasons are mechanical malfunctions, for example, a pump has failed and problems with oil.
Consequences
If during starting, after the engine warms up, the knocking does not disappear, then the cause should be identified as soon as possible. They are often associated with poor oil, as discussed above. According to statistics, an average of 65% of hydraulic lift problems are caused by using the wrong fluid. If you ignore the problem, you can accelerate the wear of the timing mechanism. Plus, due to knocking, and these are blows by and large, the cams on the camshaft suffer, as well as third-party mechanisms connected to the timing. In addition, not timely elimination of knock problems will lead to an increase in fuel consumption, a decrease in power, and an unstable operation of the internal combustion engine.
Conclusion
As a result, I would like to once again pay attention to the importance of timely identification of the reasons. Do not pay attention to the comments of some car owners on the forums, where they say that if the GC stops knocking on hot, then everything is fine. This is a delusion, subsequently, unequivocally, in a day, a week, a month, but still there will be problems with work and hot. In a very bad situation, there is a threat of failure of the timing mechanism, wear of the camshaft cams due to constant blows, loss of power, and an increase in consumption. You need it? And the main thing that you probably learned from the article is that you need to choose the right oil. Because the performance of this unit directly depends on the choice of fluid.
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Having started my car from under the hood, suddenly an incomprehensible knock... Do not panic. Most likely a car knocked hydraulic lifters... This problem is common in both domestic cars and foreign cars. Let's analyze why hydraulic lifters knock on cold and hot, and what to do in this case?
Hydraulic lifters knock on cold and hot. This malfunction occurs not only in supported cars with high mileage, but also in cars that came off the assembly line.
If an annoying sound appears, do not rush to the car dealer to buy new parts. In this article, we will look at ways that can help get rid of this annoying knock. First, let's figure out what hydraulic lifters are, where they are and why they make a knock.
Hydraulic lifters, in plain language, a device whose main purpose is regulation of valve clearances engine. Located between the camshaft cam and the valve. The clatter of the hydraulic lifter indicates a malfunction. This happens due to the fact that the compensator does not have time to select the gap, thus, does not cope with its work.
Malfunctions can be in the hydraulic compensator mechanism itself or in the oil supply system.
The first includes:
- The impact surface of the spring pair is worn out.
- The presence of marriage.
- The oil supply valve can become clogged, causing it to stick.
- The presence of air in the hydraulic compensator device. Such a problem appears sometimes due to a lack of oil.
- Carbon deposits on the hydraulic compensator parts.
Secondary reasons include:
- Air in the system, or the oil level is lower, higher than necessary.
- The oil supply system is clogged with carbon deposits.
- The oil filter is out of order.
- The viscosity of the oil is not suitable for the climatic conditions.
- Due to engine overheating.
Mostly due to poor quality or used engine oil. The solution is simple. Fill in a new one. There may also be a problem with a worn oil filter. Check it out, and if so, your best bet is to replace it. If the problem persists, then there is a malfunction in the engine components.
Hydraulic lifters knock on cold too. But the peculiarity lies in the viscosity of the oil. Because when heated, it changes its viscosity, into a more liquid state. This is the knock of the hydraulic lifter. Therefore, you should not pay for the rougher operation of the engine, which has just started up.
What does the knock of hydraulic lifters lead to
- Timing drive wear.
- Cylinder head wear.
Finally…
If the problem is in the engine oil, then it is not difficult to fix it yourself. If in the hydraulic lifters themselves, then it is best to contact the specialists at the service station, who will carry out high-quality diagnostics and carry out repairs. If necessary flushing of hydraulic compensators, then again, you can handle it yourself.
Serve your car, change engine oil and filters on time, and you will not have hydraulic lifters knocking.
What do faulty hydraulic lifters lead to? Just to reduce the service life, and they also have a slow and destructive effect on the cylinder head. We will not upset you in advance with information about the cost of repairing these units.
Video on how to check hydraulic lifters:
With regards to the repair of hydraulic expansion joints itself. It's up to you to try or contact qualified specialists. In principle, you can diagnose the wizard and establish the cause of the malfunction. And if, for example, you just need to flush the expansion joints, then you can do it yourself. In the event that more complex repairs are required, we advise you to use the services of professionals. Because an illiterate intervention can result in high repair costs for you in the future. It is often much easier and more profitable to immediately contact a good service, where knowledgeable people will do all the work.
P.S. Write to us in the comments, have you ever encountered knocking hydraulic expansion joints? And if so, what was the reason and how did you manage to eliminate it.
A modern engine runs quite quietly, and extraneous noise is heard almost immediately. By sounds, you can diagnose a variety of malfunctions - from extremely dangerous to simple ones that you can still travel with. It often happens that hydraulic lifters knock in the engine. To understand the causes of the problem, you need to study their structure.
Gas distribution mechanism
The fuel mixture enters the cylinders through special holes in the cylinder head. They are opened and closed by poppet valves, which are driven by pushers.
The latter, in turn, are driven by cams (protrusions) of the camshaft, which rotates at a certain speed. The cams are located in a sequence of cylinders. The pushers get hot during operation. This is due to the fact that the cams act on them with considerable force, and on the reverse side they are supported by a return spring. Heating causes thermal expansion. As a result, the cams push harder on the pushers, and the gap between them completely disappears.
What is a hydraulic lifter
These devices automatically adjust the thermal gap, allowing the operation of the gas distribution mechanism without shock loads. Such elements appeared on multi-valve motors, since it is rather tedious to regularly check and correct thermal clearances. Outwardly, these devices resemble metal cylinders, consisting of a spring-loaded plunger pair. Oil is fed into it under pressure. But due to the fact that these parts work under constant load, as a result of various factors, hydraulic lifters knock when starting on a cold one.
Main manufacturers
Of course, original parts and consumables, those that were installed at the factory, are of better quality and more reliable. Therefore, we must strive to preserve their performance. Nevertheless, sometimes analogs are superior to the original.
Hydraulic lifters are manufactured by a wide variety of companies. But most of all the Germans have succeeded in this. Hydraulic lifters from INA, SWAG, FEBI have proven themselves well in reliable and long-term operation of a wide variety of engines. Also, these parts are produced by AE and AJUSA - they are also European, but, according to reviews, have a low workmanship. Elements can start knocking after several thousand kilometers. The main problem for all such parts is the danger of scrap or poor quality raw material. As a result, rubbing surfaces are quickly developed - the hydraulic compensator knocks on cold and hot. Driving with such a malfunction is highly discouraged.
Causes of knocking
As already mentioned, hydraulic lifters reduce thermal clearances and automatically adjust them during engine operation.
There are three main reasons for knocking:
- Mechanical wear of hydraulic lifters or their defects during production.
- Malfunctions in the engine lubrication system.
- Features of engine oil.
All three reasons can be analyzed in more detail and find out why the hydraulic lifters knock (on a cold engine as well).
During operation, various defects and natural wear and tear appear on the working surface of these elements. In addition, the parts themselves and the oil supply valve can become seized due to insufficient lubrication.
Another reason for the knock of hydraulic lifters is contamination of the lubrication system. Naturally, resinous deposits can in no way contribute to the good processing of rubbing parts. Dirt and deposits not only impede the proper functioning of the machine, but also significantly accelerate wear.
Another cause of knocking is problems with the oil filter, which may be a poor-quality bypass valve. Because of this, the lubricant is poorly cleaned. Oil selected out of season and with unsuitable characteristics can also cause the hydraulic compensator to knock on a cold, as well as on a hot engine. The mass may be too viscous, but on a hot engine - on the contrary, liquid, and not provide the fullness of the lubricating properties.
A serious reason that the hydraulic compensator knocks on a cold one can be the consequences of engine overheating. It is also the ingress of antifreeze or fuel into the engine lubrication system, excess crankcase gases due to faulty or clogged ventilation. Thus, foreign matter gets into the engine oil. As a result, its physical properties change, hydraulic lifters begin to tap. This sound can appear at different periods of engine operation - at the beginning of work, on a warm or cold engine, under load or without it. Most often, the hydraulic compensator knocks on a cold one, and this happens immediately after changing the engine oil. Here it is necessary to dwell on the factors causing this malfunction.
What to do if hydraulic lifters knock on a cold
The reason for the sound may be simple - not fully heated oil simply did not have time to reach the plunger pair. Metal parts knock against each other in the absence of lubrication. Over time, the liquid disperses through all elements and the ringing disappears. It often happens that hydraulic lifters knock on the cold on the Prior. The reasons may be the same, because the timing design is typical for such motors. Malfunction or wear of the hydraulic compensator itself, clogging of the lubrication system, poor-quality oil or its inappropriateness to the season and type recommended for this engine, causes similar problems.
You can also list a list of reasons that help answer the question of why hydraulic lifters knock on a cold one:
- Malfunction of the hydraulic compensator itself, its development. It should be noted that in this case it will knock even when the engine is hot. Therefore, this version can be considered only after checking all the others. Here, the only option is a complete replacement.
- The engine oil is too thick due to an inappropriate season and type of application. There is only one way out - to change the lubricant.
- The outflow of oil from the unit itself when the engine is not running, as a result of which air enters the hydraulic compensator. It interferes with the normal operation of the mechanism. This is due to the leakage of the hydraulic compensator valve, which should be replaced, and the unit itself should be flushed and pumped.
- Clogged oil inlet in the hydraulic lifter housing. When the engine is running, fluid heats up and seeps in, and deposits and dirt can prevent this.
How to identify a faulty item
It is quite simple to identify a failed hydraulic compensator.
With the valve cover removed, press down firmly. A serviceable element will hold the load, and a worn one will fail even under slight pressure. In the same way, it will fail and not compensate for the clearance when the engine is running. Extraneous sounds are inevitable here.
Why do new hydraulic lifters knock on a cold one?
New mechanisms must be worked in. Therefore, a slight knock at the beginning of work is considered the norm. But if the sound continues after a long work, then it’s not about them. Of course, the possibility of a manufacturing defect is not excluded, for which it is advisable to issue a guarantee when buying.
Nevertheless, the knock of new hydraulic lifters may be associated with their incorrect installation. As a result, they are not filled with oil properly.
Consequences of a hydraulic compensator malfunction
Naturally, many are interested in the question of whether it is possible to operate a motor with knocking valve clearance compensators. It is possible, but undesirable, because the car will not meet the declared parameters, namely:
- The engine power will decrease and the fuel consumption will increase.
- The elasticity and throttle response of the engine will decrease (it will be worse to gain momentum).
- Increased vibration and noise, as well as a decrease in the total resource of the gas distribution mechanism.
Therefore, knocking hydraulic lifters are equated with engine malfunction and require prompt repair or elimination of the cause of the problem.
Preventive actions
To ensure the smooth and long-term operation of hydraulic lifters, it is necessary to follow fairly simple operating rules.
We will list them below:
- First, change the engine oil in a timely manner. Moreover, be guided by the recommendations of the manufacturer and seasonal characteristics: in winter, fill in more liquid, in summer - thicker, so that at the operating temperature of the engine, the characteristics of the lubricant are the same.
- Secondly, when a knock occurs, it is necessary to identify its cause as soon as possible so that this malfunction does not lead to the emergence of others. After all, knocking compensators are a sign of a malfunction not only of the latter, but also of many other systems and assemblies of an automobile engine associated with them.
So, we found out why the hydraulic lifter knocks on a cold one, what to do with it and how to solve the problem.
