Why does the oil pressure gauge go up and down while driving?

Your car’s smooth operation is based on several mechanical parts that coordinate to make a complete run. That includes some small but susceptible parts in your vehicle to monitor how you are operating the whole system, as well as other warning parts.

For example, there is an Oil Pressure Gauge, an important part of a car that indicates general wellbeing, and a warning system that gives early notice of any car issues. It monitors and measures the oil resistance through the engine parts pumped by the motor oil pump. 

How Oil Pressure Gauge works

As pointed earlier, the oil pressure gauge measures and monitors the oil pressure entering the engine and its entire accessories. This gauge is placed in one of the ways for oil or oil pipe. For efficiency, the gauge has a tapping in the engine that is helped by an installed sensor. 

The screwed sensor works as an electric gauge, but still, there is another part, the mechanical gauge, that acts as a take-off pressure detector. For warning, a light signal is installed on the T-piece or union, although it doesn’t matter whether the vehicle is featured to oil pressure gauge ideal or not. In addition, a mechanical gauge is featured to monitor the oil pressure; it has a needle-like dial pressure under the engine.

How to read an oil pressure gauge

The oil pressure gauge is designed to work in indicating both low and high-pressure levels. Here is how you can read the meter.

Low Reading(L)

A low reading of your car’s gauge can be noted when the needle pointer reads 20 or below. But first of all, you have to know a gauge has a dashboard that ranges between 1-80 or 1 to 100 readings. So when the gauge reads 20 or below, it can indicate that oil pressure has dropped or some engine compartments have a workout.

High Reading(H)

This reading is indicated by the needle-on gauge reading high ranges near the maximum reading. Therefore, when the car shows high reading, it may indicate issues with high oil pressure.

Reasons for a fluctuating oil pressure

While it is normal for an oil pressure gauge to fall and rise while driving, here are some reasons why it happens. 

1. An actual automotive problem

An oil pressure gauge can rise and fall if the car has an automotive problem, but it is rare.

2. Fluctuation in oil temperatures

Sometimes the oil temperatures can fluctuate from cold to hot; as this fluctuation comes, the oil pressure gauge will also change as per the oil temperatures. 

3. Low oil pressure 

When the oil has low pressure, the pressure gauge will keep changing. If it fluctuates and shows a high oil pressure, then it means that there is a problem with the pressure release valve.

4. Mechanical problems

Some mechanical problems can make your car’s oil pressure gauge fluctuate or lead to an unstable oil pressure reading. This usually occurs after overhauling an engine. 

5. Damaged oil pressure sending unit

First, when you have a fluctuating oil pressure gauge, you should confirm if you have enough oil because less oil in the tank can interfere with the oil pressure gauge reading. But if you find enough oil, the problem can be that your oil pressure transferring unit is faulty. 

6. Worn engine bearings or worn oil pump

In some cases, a worn engine bearing can make the oil pressure reading indicate a low reading. Moreover, a broken pump can make the reading keep fluctuating. 

7. Low-pressure oil viscosity

Car oil needs to be changed after some time; this is because, as the oil continues to last, it loses its viscosity. This will then result in a low pressure reading on the gauge. 

8. Diluted or worn out oil

If you fill your tank with diluted oil, then expect to experience gauge fluctuations. This is because a worn-out oil or a diluted one can tamper with the expected reading of the oil pressure gauge. 

9. Low oil levels in the tank

Low levels of oil in the tank can make the oil pressure gauge increase and reduce while driving. Therefore, when you experience fluctuations, you should first check if the tank has enough oil. And if it is not enough, then less oil pressure is the likely reason for the oil pressure gauge fluctuations. 

10. Oil pressure Gauge problems

Sometimes, we should not look for problems too far. If your oil pressure gauge fluctuates, there is a likelihood that the indicator itself is problematic. These gauges occasionally go wrong, although in rare cases, so you should not overlook this. You should check the indicator to see if it is working as required. 


It is normal for an oil pressure gauge to fluctuate while driving, but you should not ignore it as it can indicate a serious problem. For example, the oil pump will spin faster when the motor spins faster, leading to high oil pressure. But if it persists, then it means that any of the above has a problem.

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