How to check the causes of low and high engine oil pressure

Is the engine oil pressure light on your car's dashboard? This means that problems are possible in the power unit. We advise you to take immediate action because this small malfunction can cause big problems.

Deviation from the specified parameters of the oil pressure in the engine is fraught with failure of the components of this unit, even leading to an accident. If measures are not taken on time, major repairs or even complete replacement of the motor will be required.

Let's figure it out in order:

why and what oil pressure is needed in the engine,
how is engine oil pumped?
what are the consequences of deviations from the specified values,
How do problems appear?
how to diagnose and fix problems.

What builds up the pressure?

Regardless of the type of power system and timing system, on all internal combustion engines a special pump is involved in this process. It is located in the area of the engine crankcase. This mechanism is driven by gears that rotate the motor during operation.

As a result, the lubricant begins to move through the channels to the right places. This is the camshaft, crankshaft, piston system and much more. It is the pump that is responsible for the oil pressure in an internal combustion engine. What happens if his work stops? We will talk about this below.

Engine lubrication system: what it is and how it works

The automotive lubrication system is designed to create an oil film on the rubbing surfaces of parts that interact with each other. This film reduces power losses and reduces wear on the power unit. Of course, the quality of the film depends on the quality of the oil and the technical condition of the lubrication system, which is part of the engine structure and includes the following elements:

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The optimal pressure should be

This parameter depends on several factors:

displacement,
manufacturer,
model,
engine type (gasoline, diesel)

The exact data on what pressure in the engine needs to be maintained is indicated in the technical documentation for the car. If we take average figures, for gasoline engines this figure is equal to:

at idle speed - about 2 atm. (0.2 MPa),
at 4000-5000 rpm - from 4.5 to 6.5 atm. (0.45 – 0.65 MPa).

For diesel engines, the figures are approximately 40-50% less. But these are only approximate figures. On some models of gasoline and diesel engines, minor deviations are possible, both up and down.

In general, we can present the average pressure values depending on the engine size in the form of a table:

Engine:	Meaning:
1.6 l and 2.0 l.	2 atm. at idle speed; 2.7-4.5 atm. at 2000 rpm.
1.8 l.	1.3 atm. at idle speed; 3.5-4.5 atm. at 2000 rpm.
3.0 l.	1.8 atm. at idle speed; 4.0 atm. at 2000 rpm.
4.2 l.	2.0 atm. at idle speed; 3.5 atm. at 3500 rpm.
TDI 1.9 l. and 2.5 l.	0.8 atm. at idle; 2.0 atm. at 2000 rpm.

For example: the pressure of a VAZ 2112 engine (gasoline) at idle is 1.5 - 2.5 bar, and at 5000 rpm it increases to 4-6 atm. It can be seen that at idle the pressure is approximately within the standard parameters, and at higher speeds it is slightly below normal.

If you decide to measure the oil pressure in your car, keep in mind that this should only be done when the engine is fully warmed up. This parameter should not be measured on a cold engine - the data will differ significantly from the actual operating readings.

Malfunction: the crankcase ventilation system is clogged

Many car owners have a vague idea about the crankcase ventilation system of their car. Since for a long time, while the car has low mileage, it works unnoticed, without giving away its existence. After years and (or) hundreds of thousands of miles, the ventilation system gradually becomes clogged, showing the first signs of its malfunction.

Signs of malfunction: the crankcase ventilation system is clogged

Drives engine oil out of the engine under seals and gaskets

Since the ventilation system is responsible for the timely and effective removal of gases from the engine crankcase into its intake tract, the slightest narrowing of its channels due to the appearance of deposits in them leads to an increase in pressure in the crankcase and in the engine itself. Increased pressure causes engine oil to leak under the crankshaft and camshaft seals, pan gasket, valve cover gasket, and oil filler plug. Replacing oil seals and gaskets in such a situation does not solve the problem of oil leakage.

Engine air filter housing oil

(for carburetor engines)

Due to the reason described above for the increased pressure in the engine crankcase, the engine oil contained in it begins to be actively released along with gases under the valve cover and further into the air filter housing. Clogging the filter element and carburetor jets.

Increased engine oil consumption

Since engine oil begins to be actively released into the engine intake tract and burns out in the combustion chambers, its consumption increases accordingly. At first, almost unnoticeable, it gradually grows as the ventilation system becomes clogged.

Oiling of spark plug electrodes

Due to engine oil entering the engine intake tract and further into the combustion chambers, the spark plug electrodes become oiled. The spark plugs begin to work intermittently, the engine idles, there are dips and jerks in movement, and blue smoke from the muffler.

Causes of the malfunction: the crankcase ventilation system of the car engine is clogged

High car mileage

Sooner or later, the engine crankcase ventilation system ceases to effectively cope with its responsibilities since it constantly has to deal with crankcase gases carrying particles of oil, soot, etc. Over time, all this clogs the system’s oil separator and settles in the form of soot deposits on the walls its hoses and tubes.

Use of low-quality oils

The process of clogging of the crankcase ventilation system can be accelerated by constant operation of the car engine with low-quality and (or) engine oil unsuitable for the given engine. In this case, the amount of soot deposits increases significantly.

Wear of the engine piston group

A worn-out piston group of a car engine (rings, pistons, cylinders) allows a large volume of gases from the combustion chambers to break into the crankcase, increasing the pressure in it and contributing to the onset of negative consequences.

What to do if there are signs of clogging of the crankcase ventilation system?

Change the engine oil to an appropriate and high-quality one.

Check the compression in the engine cylinders to determine the degree of wear of its piston group.

Notes and additions

On engines in which the design of the ventilation system allows, there is a practice of eliminating the negative consequences of clogging of the ventilation system and piston wear, which consists of leading the main hose of the system under the engine. In this case, crankcase gases are released into the atmosphere. Since they are poisonous, the environment suffers.

Why is an engine crankcase ventilation system needed? The system is designed to remove gases from the engine crankcase into its intake manifold, which prevents an increase in their pressure and, as a result, oil leakage under the oil seals and seals. In addition, afterburning of harmful crankcase gases leads to a decrease in exhaust toxicity.

Closed crankcase ventilation system. With forced removal of gases (due to vacuum in the intake manifold). Gases are sampled through an oil separator, which cleans them of engine oil particles. Gases are removed through two circuits (main and idle).

Example: design of the crankcase ventilation system of a car engine.

1. Engine crankcase.

3. Hose from the breather to the valve cover pipe.

4. Oil separator under the valve cover.

5. A thin hose from the valve cover to the fitting with the throttle body nozzle.

6. Fitting with a jet on the throttle valve block.

7. Thick hose from the valve cover to the inlet pipe.

Source

Causes of low engine oil pressure

Low pressure in the oil system is most often due to the following reasons:

Insufficient engine oil level.
High resistance of the oil filter (either the filter is faulty due to the fact that it has not been changed for a long time, or due to the use of very poor quality oil).
Damage to the oil pressure sensor.
The engine is filled with low-viscosity oil that does not meet the tolerances and requirements of the car manufacturer.
Reduced oil viscosity due to fuel getting into it. As a result, the engine oil dilutes and, as a result, the pressure in the oil system drops. Fuel may get into the oil due to a failure of one of the cylinders. In this case, during engine operation, the fuel mixture does not burn in the cylinder, but accumulates and, due to the movements of the piston along the cylinder walls, enters the engine crankcase. And the greater the wear of the cylinder-piston group and the greater the gaps between the cylinder walls and the piston itself, the more fuel gets into the oil. And it doesn’t matter whether the ignition system is working properly or not - if the engine is severely worn, fuel can still get into the oil along the described path. Fuel can also enter the engine oil through a worn, leaking fuel pump diaphragm.
Oil dilution due to coolant, which can enter the engine through a poor-quality, incorrectly installed or warped cylinder head gasket as a result of overheating.
Increased gaps between the connecting rod journals and bearings due to increased wear.
The oil pump cannot provide the required level of pressure due to deposits on the internal surfaces of the pump parts, due to wear of its parts and due to contamination of the oil receiver mesh, which does not allow oil to pass through well.
Wear of the cylinder-piston group. As wear increases, the clearances between the piston and cylinder increase. In this case, oil drains from the walls faster than necessary, which leads to low pressure in the oil system.
When the crankcase ventilation system becomes clogged or fails, a large amount of excess crankcase gases is formed in the lubrication system, which in turn also causes low oil pressure in the engine.
Damage to the pressure reducing valve, which performs the function of normalizing the pressure inside the oil pump system.
Oil leaks through cracks in the engine sump.
Poorly performed engine overhaul, during which the valves or crankshaft were replaced (due to inaccurate installation of the valve, the seal in the cylinder is broken and, as a result, the pressure and power of the engine drop)

With many malfunctions, only repairs or at least a basic replacement of the oil and oil filter will help.

But you can try to cope with the causes of low pressure due to wear of parts yourself, using additives to restore worn surfaces of engine parts. In this case, you can save a VERY decent amount on repairs, because the cost of additives is an order of magnitude less than the price that the service center will ask you to repair the engine.

Today there is a very wide list of different engine additives on the market.

The bulk of these additives do not fight the cause, but only the consequences of any problems: they change the physical and chemical characteristics of the oil (for example, additives to increase viscosity) or modify the surfaces of parts to reduce their friction.

In contrast, XADO revitalizant additives restore worn surfaces of parts without changing any properties of the oil. They eliminate the root cause of the decline in engine technical characteristics - their WEAR.

During the revitalization process, a metal-ceramic coating is formed on the surfaces of friction pairs, restoring defects and microdamage to parts.

rice. Operating principle of the Hado reducing additive

And it is precisely due to this that the oil pressure increases in an engine treated with XADO additives.

rice. An example of restoration of a worn-out surface of a part using Hadot revitalizant.

Result of checking

If the pressure gauge shows normal oil pressure in the power plant, but the control indicator continues to glow treacherously after connection, then the reason for its activity lies in its malfunction. Replace the sensor with a new one and enjoy your trips further.

High blood pressure

Causes

If you are lucky enough to encounter the problem of high blood pressure, then you need to figure out what caused it. This disease occurs for the following reasons:

Using oil that is not suitable for the engine technical parameters. If you ignored the manufacturer's instructions and poured the first liquid with an excessively high viscosity into the engine, the problem will not be long in coming. It becomes especially relevant when using summer lubricants in winter.
Obstruction of oil channels and filters. Oil pressure is affected by clogging of the lubrication system paths and filter elements of the structure. A large amount of soot, soot and metal shavings clog the channels through which the oil circulates. As a result, the same amount of liquid continues to move through the “cut down” system, increasing pressure inside it.
Reducing valve malfunction. The valve does not provide the required dosage of fuel and lubricants and leaves in the system an excess amount of oil for the cycle. As a result, the free space required for effective functioning is reduced and the pressure increases.
Malfunction of the bypass valve. Its main task is to supply working fluid from the pump to the channels of the lubrication system, bypassing the filter element if it is clogged. If there are malfunctions in its operation and it begins to leak oil while the filter is functioning, the pressure in the power plant increases.
Exhaust valve defective. Exhaust gases must leave the structure and not accumulate in it. The pressure in the engine lubrication system may increase due to the failure of the exhaust valve: the gas-air mixture will fill the crankcase and increase the pressure of the oil lubrication.

Filter

To clean the oil, a filter is installed in each engine. It looks like this:

Experts note that this element should be changed at every oil change. For gasoline engines this is 8-10 thousand kilometers, for diesel engines - 12. During this period of time, the filter accumulates a lot of dirt. These are waste products, small shavings, and other debris. Each filter has a bypass valve that serves to supply oil directly in the event of a clogged cleaning element. But it doesn't work correctly for everyone. As a result, the lubricant is retained inside the filter and reaches important areas under low pressure. You should not save on this element. Buy only original filters. This will significantly extend the life of the engine and prevent it from running on low oil pressure.

The installed oil filter is of poor quality or clogged

To avoid oil starvation, there should always be some amount of engine oil in the oil filter when starting the engine. The lubricating fluid is held there when the power unit is turned off thanks to a lock washer or check valve.

If the filter is of poor quality, then the above elements may not cope with their task or may be absent altogether. In this situation, the oil returns to the oil pan. This leads to the fact that when pressure builds up, the switched on engine experiences oil starvation, which causes increased wear of its parts.

A clogged oil filter puts additional stress on the oil pump. In addition, it causes a decrease in pressure in the system.

Signs of low engine oil pressure

The most obvious sign is the indicator light on the panel that lights up. It is this that indicates a serious problem with the oil in the engine. Indirect signs include the following:

Increased emission of black exhaust gases - this may mean that the engine has overheated.
Due to increased friction of parts, they become loose and knocking or vibration may occur.
Bearings are flying.
As a result of low pressure, the lubricant burns out faster, which causes a specific odor.

The above are indirect signs, which means that the detection of one or more is not always a consequence of low oil pressure. However, if they are detected, the initial measure should be to check the oil pressure in the engine.

What are the consequences of different blood pressure?

Car enthusiasts more often encounter cases of unacceptably low pressure in the engine, so we will first consider this problem.

Dangers of Low Engine Pressure

If the pump does not provide sufficient pressure, the engine experiences oil starvation. A sufficiently strong lubricating film does not form on the surface of the friction pairs, which leads to increased wear. Insufficient oil pressure also leads to malfunction of hydraulic compensators.

A faulty timing chain tensioner can cause the piston to hit the valves, resulting in the need for major repairs. If a collision of parts occurs while driving at high speed, the consequences will be catastrophic. The same is the case with parts jamming due to oil starvation.

Causes of a sharp drop in pressure

A sharp drop may occur in some cases:

pallet breakdown. A similar phenomenon can occur when driving on roads with potholes and potholes. When there is a breakdown, the oil leaks out quite quickly. The lubrication system cannot operate. The “Check engine” indicator will immediately indicate a problem;
pump failure. This phenomenon occurs quite rarely, but drivers can share that they have encountered a similar phenomenon. On modern vehicles, indications of errors in the lubrication system will appear quickly. On older cars you will have to listen to the engine (not the best option, but another is not always possible);
Oil loss through leaks in the connection of internal combustion engine components can occur as a result of poor-quality assembly, as well as when using spare parts of inadequate quality. The oil does not flow out immediately. In parking lots, you can observe the formation of oil stains. Such phenomena should alert the car owner. You will have to constantly monitor the oil level using the dipstick readings. If necessary, you need to top up. However, this approach can be considered temporary. It is impossible to do without repairs.

Violation of system tightness

This could be a seal leak, causing some of the oil to leak out. The problem is accompanied by oil burns. Moreover, the lubricant does not burn in the cylinders (as happens when the rings are stuck and the piston is scuffed), but simply flows out. This malfunction is typical for engines with a mileage of 150 thousand kilometers. This can be solved by installing a new crankshaft oil seal. Please note that there are several of them - front and rear. Also, when replacing, the oil and filter are changed. After this, the problem goes away by itself.

Purpose of motor oil

Some ignorant car enthusiasts mistakenly believe that lubrication is necessary for the engine only to prevent premature wear of rubbing parts. Of course, the formation of a special protective film that reliably envelops the moving elements of the power unit is the main purpose of motor oil. However, its functions are much more advanced:

During engine operation, excess heat is generated in the cylinders. Motor lubricant does an excellent job of removing it;
with the help of special additives, the oil helps cleanse the power unit from various deposits;
The combustion process of fuel is usually accompanied by the formation of excessive amounts of oxides. A lubricating substance is used to neutralize them;
Also, the purpose of motor oil is to prevent corrosion on the functional elements of the engine.

Oil plays a fairly significant role in ensuring the normal operation of the power unit. Just as a person cannot exist without sufficient blood, a motor cannot function without lubrication.

Therefore, it is so important to pay due attention to timely oil changes, as well as monitor its pressure indicators

Signs and remedies for high pressure in the engine

If your vehicle is equipped with a digital engine pressure indicator, you can easily determine if the reading exceeds the recommended value. But this is an advantage of equipment in an expensive price segment, which is not available to everyone.

If the engine pressure is diagnosed to be too high, the problem is most likely caused by a dirty pressure relief valve. In most cases, it is enough to flush the lubrication system. Regular use of Suprotek flushing can almost completely eliminate problems with the valve mechanism.

Helpful advice

Oil pressure is also affected by its viscosity. Do not use too thick oil for the winter. Firstly, it will make it difficult to cold start the engine. Secondly, it is possible that the pressure drops 20-30 percent below normal.

If you have a car with more than two hundred miles, you should not pour too thin oil (for example, 0W30). Yes, it makes it easier for the engine to start. But due to worn oil seals and gaskets, most of it will leak out. There are often cases when it took up to three liters of oil to top up. In this case, the best option is 10W40.

How often should you measure your blood pressure and why?

Depending on the operating conditions, it is important to determine the frequency of measuring the pressure, since the oil pressure light may not light up for a number of reasons, and therefore you should not rely heavily on it. Therefore, it is better to choose a replacement interval that is individual for each vehicle and conditions of use.

In a gentle operating mode, you can limit yourself to generally accepted standards, according to which it is recommended to check the oil pressure level every 1-2 thousand km. For very infrequent trips, measurements can be taken once a month.

Emergency indication of engine oil pressure

At the moment, almost every car is equipped with an emergency indicator, which indicates a lack of pressure. It is popularly known as a “burning oil can.” If it fades out within 10-20 seconds after starting the engine, then you don’t have to worry. The oil filter is to blame here. A constant glow of the light indicates more serious problems - a breakdown of the pressure sensor, failure of the oil pump, etc.

Pay attention to the emergency indication. Ignoring problems can lead to major engine repairs. If the light comes on, quickly turn off the car and take a tow truck or tow truck https://volok-evakuator.ru/lotoshino.html to a good service station.

Possible problems

The most common problems encountered by motorists are failure of oil pump parts, filters (usually due to wear), loss of tightness of components, violation of adjustments or mechanical problems with pressure reducing valves. Malfunctions of the engine lubrication system are usually associated with two groups of problems.

Problems that lead to a decrease in oil pressure. They can be the result of deformation, wear, damage to the oil pump, low oil level, clogged filter, failure of the oil sensor, or sticking of the pressure relief valve.
Problems that lead to increased oil consumption. This is the result of failure of the gas distribution mechanism, wear of the pump gasket, clogging of the crankcase ventilation, damage to the crank mechanism, weakening of the oil filter (or an initial error in securing it).

To identify pressure indicators, warning lights are used on the vehicle’s instrument panel. Low oil pressure is a direct signal indicating that the vehicle cannot be driven and requires repair or maintenance. To determine oil consumption, modern cars with automatic equipment have a special indicator lamp on the instrument panel. To determine the problem in vehicles without such a lamp, a feeler gauge is traditionally used.

Wear and deformation

If diagnostics show that the parts are worn out, that is, they have served their service life, in most cases there is no point in trying to restore them. It needs to be changed. Gaskets, caps, and filter seals have a service life (indicated in the documentation for the parts), and if they are not replaced, the number of problems can only increase. For example, untimely replacement of the filter leads to a critical concentration of harmful impurities, which can lead to deformation of not only the filter itself, but also the housing. Deformation of the housing can be caused, for example, by wear on the outer surface of the pump bushings. By the way, about deformation. It can occur much earlier than wear itself. But to solve the problem, you will have to not only change the deformed part, but also eliminate the cause that led to this trouble.

For example, with mechanical deformation, the root of the problem is often in malfunctions of other components interacting with the SSD. In particular, deformation of parts of the lubrication system may be a response to the failure of silent blocks or failure of the internal combustion engine. However, it is a comprehensive diagnosis that is important here. You shouldn’t immediately “blame” the engine mounting or silent blocks. For example, in a situation where timing valve parts are deformed, the quality of the oil is often to blame.

Fault prevention

The most effective prevention of malfunctions is regular qualified maintenance:

Systematic replacement of the oil filter.
Systematic replacement of engine oil.

In this case, you need to clearly know how much engine oil the system requires, and take into account the volume of the engine lubrication system. An insufficient amount of oil creates a load on parts, increases dry friction, and accelerates wear. Excess oil - the risk of creating excess pressure and damaging the camshaft and crankshaft seals, “killing” the seals and breaking the tightness

Important! Along with replacing the oil pump, it is always important not to be lazy and replace the oil filter

An important element of prevention is the competent operation of the internal combustion engine.

It is especially important to start the engine correctly in frosty weather. At low temperatures, the viscosity of the oil thickens, and the path of the oil to the rubbing parts worsens.

Warming up the engine before starting in this situation is a necessary operation.

Timely maintenance and prevention means providing lubricants to all parts that come into contact with friction, protecting the internal combustion engine from overheating and combustion residues, damping vibrations and suppressing noise.