Why Does The Oil Pressure Gauge Go Up And Down While Driving

Maybe you must have noticed some unsteady movement on your car’s oil pressure gauge while driving. A low oil level might be the most probable cause to think of. A faulty oil pressure gauge might also be another cause or a failing oil pump. A blown head gasket can also be another reason why your oil pressure gasket moves up and down while your car is in motion. The oil pressure gauge can also make unsteady movements because of a worn-out oil pickup O-ring.

Is It Normal For Oil Pressure To Go Up And Down?

Your car’s oil pressure gauge is expected to fluctuate with the engine rpm. The oil pump moves as your car’s engine revs up. So, in order to align with the engine, the oil pressure gauge will go high when the engine rpm is high.

Your oil pressure gauge will go low during cold starts. And will go high again as your car engine gets warm again. The oil pressure gauge is supposed to always read above 5-10 PSI and below 80-100 PSI even as it is expected to fluctuate.

There is a fault with your car’s oil delivery system if the oil pressure gauge rises and falls with the engine cranking sound or it keeps fluctuating steadily with the engine RPM.

In this article, we will discuss the process of how the oil pressure gauge works, and how to read your car’s oil pressure gauge. We will also look into the reasons why your oil pressure gauge fluctuates continuously and how to fix it.

How Oil Pressure Gauge works

The level of oil flow in your car engine is measured and monitored by the oil pressure gauge. The gauges are placed at the oil pipe and from there it gets the signal from the oil pressure movement. The gauge has a connection to the engine, this is to be able to provide an accurate report. This connection is aided by a sensor.

The sensor installed in the engine works as an electric gauge for the car. there’s another gauge in the car that detects when oil moves to the engine. This is the mechanical gauge. There is a signal light installed on the union or T-piece, this is for warning purposes. Though this signal is not found in every car, it is not something to think much about.

The mechanical gauge has a needle-like monitor fixed under the engine. This is how it carries out its duty of monitoring the oil pressure.

How To Read An Oil Pressure Gauge

Though it is more common in older car models, some cars have analog oil gauges. It can be read in PSI or Bar, but it is dependent on the car’s make and model.

On the latest car models, you can read the oil pressure gauge with an OBD2 scanner. To detect the reading, the scanner has to be attached to your dashboard.

Let us take a look at how you can read the low and high readings of the pressure gauge manually.

Low Reading(L) Oil Pressure Gauge

There is a gauge dashboard in your car that has a reading between 1 – 80 or 1 – 100. When the needle pointer is at 20 or below it, the reading is said to be low. This low reading means that there is a drop in the oil pressure. An engine component getting worked out can also be a cause of this.

High Reading(H) Oil Pressure Gauge

A high reading in your oil pressure gauge means that something is wrong with your car. a high reading is when your oil pressure gauge needle reads at high ranges close to the maximum point.

What Causes Erratic Oil Pressure Gauge Movement While Driving?

There are different reasons why the oil pressure gauge can make erratic movements while your car is in motion. These reasons include;

Low Oil Level

The oil gauge will be fluctuating as you drive if your oil level gets low or your car runs out of oil. To avoid this, you can check your oil level first before you start your car. it is also important to check your car’s oil level with the dipstick after it has rested from use.

You can turn to your car owner’s manual to know the recommended oil level and how to check it too.

Faulty Oil Pressure Sending Unit

The oil pressure-sending unit is the sensor that reports your car’s engine oil pressure on the dash.

Sometimes, oil might leak out of these pressure-sending units, the oil then penetrates the electrical connection of the sensor. This will result in the oil pressure gauge making unsteady movements.

Check the sensor’s side of the electrical connection for any oil leakage, to diagnose this issue.

You can visit a mechanic to check this with a universal oil pressure monitoring sensor if you can’t look through space to see it for yourself. You should know that the fault is with your oil pressure sending unit if the oil pressure movement reads normal to the universal sensor and so it has to be replaced.

The sensor is very easy to fix so you can fix it yourself, while the oil pressure sending unit costs between $15 – $40. Many car owners have been able to return the oil reading in their cars to normal by simply fixing the oil pressure-sending unit.

Incorrect Engine Oil Filter

It is an indication that your oil filter has become faulty if your car starts at a low engine oil pressure and stabilizes to normal after a few minutes. Some engines are equipped with an oil filter that has an anti-drain back valve.

The back valve is what prevents the oil from draining if the engine is not ON. If you changed your oil filter, this might be the reason why the filter is bad. And if this is the case, the oil pressure will remain low for some time after you start your car. This is because the oil will drain into the pump when your car is off.

You should check if your oil filter is the cause and get a good one to replace it if need be.

Worn Out Oil pickup O-ring or Clogged Pickup Screen

A worn-out oil pickup O-ring is another possible cause of a fluctuating oil pressure gauge. Also, the engine oil pressure and the sensor’s reading on the dash will be reduced if your oil pick-up screen is clogged.

Driving your car with a low oil reading can cause severe damage so you should take it to a mechanic for proper fixing if you notice that it has a low reading.

Failing Oil Pump

Sometimes you may hear a knocking or squeaking sound coming from your engine bay, this means that your oil pump is about to fail. Your car engine won’t get enough lubrication as required if the oil pump gets weak. This can have very bad effects on your car because it can knock on your engine if it is not fixed.

What Does A Battery Saver Active Mean?

Other components of your car engine can also be damaged by a failed oil pump.

It is important to diagnose the cause of the fluctuating oil pressure gauge movement and be sure it is the oil pump before going for a replacement. This is because replacing an oil pump is significantly costly and involves some work.

Blown Head gasket

You can tell that your engine’s head gasket has gone bad if you start to experience oil pressure issues when your engine heats. The oil and the coolant will mix up when the head gasket becomes faulty. This mixture flowing into your car’s engine will reduce your oil pressure because the oil will become foamy when this happens.

To know if you have a blown head gasket, you will notice a low-pressure reading. Your engine oil will become foamy and your exhaust will also pump a lot of smoke. Your car’s coolant level will consequently be reduced as well.

This can damage your engine when it is not lubricated properly, so you should seek a mechanic’s attention in this situation.

What Oil Gauge Should Read While Driving?

As we have discussed how to read an oil pressure gauge earlier. Let us now talk about what your car is supposed to read while in motion. Whether you’re driving or not, the oil pressure gauge is to read between 10 – 80 PSI. It is nothing to worry about if your pressure gauge increases with the engine revs. This is because it works hand in hand with your engine RPM.

The only time it becomes a problem is when the reading is below or higher than the one stated above.

What Oil Gauge Should Read At Idle?

When your engine is idle, the oil pressure gauge is expected to read between 20 – 30 PSI. Something is wrong with your oil pressure gauge if it goes below 10 PSI after this time. And such a fault should be fixed as soon as possible.