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Oil pressure light on at idle: troubleshooting and troubleshooting
Oil pressure light on at idle: troubleshooting and troubleshooting

What can this situation mean when the oil pressure lamp is lit at idle? On the panel of any vehicle there are corresponding indicators that indicate a malfunction of a particular vehicle system. The mentioned lamp traditionally has a red backlight. If this indicator lights up while the engine is running, then there is a clear hint that the driver should pay attention to the existing problem in a timely manner and take all necessary measures.

Oil pressure lamp
Oil pressure lamp

Do I need to remind you once again what ignoring this signal can lead to? The situation can end in serious problems. For this reason, every driver needs to know what to do in such cases.

General information

In the early years, the dashboard of almost all passenger vehicles was equipped with a special "screen", which showed the pressure in the power unit. There was a scale, according to a certain unitmeasurements, - kgf/cm2. And the higher the crankshaft speed, the greater the pressure value.

If it fell below the permissible limits, then it was not necessary to be surprised that the oil pressure lamp was lit at idle. Thus, the driver received a signal that indicated a malfunction.

How are things with modern cars now? They no longer have this screen, and for a very long time. It is possible that they have been preserved on some UAZ models, but there will be very few of them, if any. However, drivers need to know the pressure parameters that are within the norm.

What is the result?

While the engine is idling - and this is usually 800-1000 rpm - the pressure level does not fall below 0.5 kgf/cm2. For most motors with 16 valves, the threshold can be slightly higher, up to 0.6 kgf/cm2. These engines are more revving and the oil they circulate is thinner.

A special mechanical oil pressure sensor is responsible for monitoring the system. In case of deviation from the norm, it sends a signal to light the indicator. The driver, seeing him, understands that not everything is in order with the power unit. When the pressure drops to less than 0.4 kgf/cm2 the lamp blinks or stays on for a short time.

Need to control oil pressure

If the driver detects a glowing indicator on the dashboard that refers to emergency oil pressure in the engine, he must immediately take appropriate measures to avoidproblems. And the very first thing he should do is turn off the engine.

Oil pressure light on
Oil pressure light on

If, despite the fact that the oil pressure light is on, it will still work, it can end very badly, up to a complete failure. And this is already unreasonably large expenses that will not please anyone.

This is exactly what explains such a forced and emergency measure, because the engine, in fact, is the most expensive equipment that is in a car. Of course, it is full of other components, mechanisms, but, with the exception of the catalyst (if any), this is the most expensive and complex device.


The car's oil supply system plays an important role in the operation of the power unit. Its most important functions include:

  • Lubrication of rubbing parts: rings, pistons, crankshaft, liners, valves.
  • Partial heat removal from the combustion chamber.
  • Washing the chips with their subsequent transportation to the pallet.
  • Creating a film that protects metal surfaces from the development of a corrosive process.

Now you can already imagine the picture that will turn out if you do not respond in a timely manner to a situation where the oil pressure lamp is lit at idle. All these and many other tasks are performed only when the optimal parameters are maintained in the engine. At the same time, the light bulb does not manifest itself in any way, which indicates the correct operation of the entire unit.

If this indicator is active,so there is a good reason. An oil pressure that is below normal is an emergency, because the power unit in this case is operating under too much load. In addition, heat dissipation is significantly reduced, which threatens to overheat the cylinder block. It is also impossible to exclude the complete failure of the piston group.

What could be causing it?

Activity of the alarm indicator may be a reason for scheduled maintenance or be the result of initial symptoms of malfunctions. So, if the oil pressure light is already on, it is necessary to identify and fix the breakdown as soon as possible.

Wrong oil pressure level
Wrong oil pressure level

Otherwise, sooner or later, it may end in inevitable problems that will be of the most serious nature. The death of the engine is unlikely to please the owner of the car.

There may be several reasons for the active manifestation of an emergency lamp in the idling mode of the power unit. Moreover, sometimes the signal light can light up for a few seconds, and then go out due to special cases of starting the engine, for example, in severe frost.

At low temperatures, the oil is thick and difficult for the pump to pump through the system. Therefore, it creates pressure below normal. This is indicated by the emergency lamp. But after a few seconds or minutes, the temperature of the oil in the engine rises and it takes on a fluid state. As a result, the parameters are normalized, respectively, the light goes out.

If this did not happen, then there is a malfunction. Below we will consider whatthis is what can be caused.

Oil and sump

The most common reason is a decrease in oil pressure in the sump or its complete leakage. Unfortunately, among many car owners (however, this also applies to the owners of various equipment) there is one bad habit that should be got rid of. This is ignoring the instruction manual.

This document clearly states that before leaving the garage, parking lot, parking lot, you should definitely check the level of all engine fluids. In case of deviation from the norm, the loss must be immediately replenished. In other words, it is necessary to regularly inspect the engine, as well as the entire engine compartment for leakage and leakage. And if the oil pressure light is on at idle, the cause can be immediately detected.

Traces of oil leakage from under the bottom of the car
Traces of oil leakage from under the bottom of the car

Each owner of his iron horse should carefully inspect the parking space under its bottom. Are there oil stains on the ground, asph alt, engine guard? Such an event allows you to detect oil leaks in a timely manner and protect yourself from increased costs.

Trying to save money

Manufacturers who treat their work with due attention value their reputation. Therefore, they try to make their products as reliable as possible. But, unfortunately, there are "artisans" who definitely do not care about quality.

As a result, oil filters appear on sale at a very low price. However, these savings do notno good: these products are not able to withstand the pressure during engine operation. Modern and high-quality filters cope with their task even in such conditions. This fact should not be discounted, as this is also the reason why the oil pressure lamp is lit at idle.

After the engine is turned off, a little oil remains in the original parts, which avoids oil starvation at the time of its next start. In the case of crafts, the consumable drains completely into the pan without lingering, which is due to the technological structure. As a result, when starting the power unit, the risk of developing rubbing surfaces increases. Because of this, the motor fails faster.

Faulty pressure sensor

The oil alarm indicator installed in the dashboard of cars is turned on by the sensor, since they are both powered by the same wire. And if the pressure in the system becomes below normal, then the lamp closes to ground with it. When the parameters are within the normal range, the sensor is open, the indicator is off.

Oil pressure sensor
Oil pressure sensor

A failure of the mechanical oil pressure sensor leads to the fact that it is constantly closed and the lamp is always active. Regardless of whether the pressure in the system is normal or not, the sensor is simply not able to open the contact. Unfortunately, a faulty sensor cannot be repaired and if the problem lies precisely in it, it simply changes to a new device.

Reducing valve problems

Reducing valve in good condition shouldalways be closed. However, over time, it may jam or freeze. In this case, the valve is already open and then the pressure in the oil system cannot be maintained at the required level. The indicator notifies the driver of the presence of a malfunction.

There are many ways to fix the situation:

  • When the spring is stretched, replace it.
  • If the valve is heavily clogged with debris, it is cleaned and replaced if not damaged.

Prevention should be carried out, which consists in the timely replacement of the oil filter and control of the consumable level. What should be the oil in the engine? Only high-quality and without pollution! In addition, before changing the consumable, flush the entire system.

Oil pump screen clogged

This element is also required, as it protects the engine and oil pump from contaminants: dust, chips, abrasive particles.

Clean and filtered oil can easily pass through the filter cells. When the consumable is heavily contaminated and contains a lot of mechanical impurities, it is difficult for it to pass through the filter. As a result, the required pressure level is not created in the oil system. And if the reason is in the grid, it must be dismantled, cleaned well and installed back.

Checking oil pressure

As we now know, for the full operation of the engine, it is necessary that the oil system maintain an optimal level of pressure.

Oil pressure gauge
Oil pressure gauge

Working parametercharacterized by the following indications for the operating conditions of the power unit:

  • Idling - 2 bar or 2.04 kgf/cm2.
  • Increasing crankshaft speed - from 4.5 to 6.5 bar or 4.59-6.63 kgf/cm2.

Deviation in any direction threatens with sad consequences for the engine. How to check the oil pressure in the engine if the dashboard is not equipped with an arrow or digital indicator? To do this, use an oil pressure gauge.

The whole verification procedure is as follows:

  • The engine starts and warms up to its operating temperature (90 °C).
  • Engine stops, hood opens.
  • The emergency oil pressure sensor is disconnected and a pressure gauge is connected instead (you need to act carefully: the oil temperature in the engine is already high).
  • Now you should check the level of the consumable and add oil if necessary.
  • The engine starts again.
  • Pressure is being measured: first in idle mode, then at high crankshaft speeds.

To obtain more accurate data, the test should be performed 2 or 3 times, and then calculate the average value of the readings. It is worth considering that when the pressure gauge is disconnected, part of the oil may spill out, so after the procedure it is worth checking its level again on the dipstick and, if necessary, topping up consumables. Just don't buy low quality engine oil.

A small but important note

Some cars have onboardthe computer system may interpret the indicator light off as a malfunction. Therefore, the vehicle is put into emergency mode.

In this case, it is not possible to increase the number of revolutions of the crankshaft, which ultimately does not allow an oil pressure check. And if the situation takes place, you can not do without the help of service center specialists.


The situation when the emergency oil pressure warning light comes on may not always be dramatic. The main thing is to respond to the signal in a timely manner and start looking for the reasons as soon as possible. It is necessary to work out all possible options step by step. How to check the oil pressure in the engine has already been indicated, so if possible, you should start with this procedure.

pressure reducing valve
pressure reducing valve

If the problem is found and fixed on your own, you can praise yourself for the work done. This will give self-confidence and partial knowledge of the car.

In case of difficulties, it is better to contact the nearest vehicle service station. It will not be difficult for professionals to find the cause and eliminate the existing malfunctions.

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