The oil pressure fluctuating while driving is a common and normal problem. Yet, you don’t want to ignore this dilemma because it can warn you of the potential failure in the engine system.
This issue happens for various reasons, and most of them are simple to troubleshoot. If the oil pressure gauge fluctuates, examine the oil level first and top it up if essential.
Also, inspect for potential leaks when the problem persists.
We will go through the most popular causes of this problem and follow the ultimate guide on fixing them in this article.
What Does It Mean When Your Oil Pressure Gauge Fluctuates?
The oil pressure is a critical factor in determining the life of an internal combustion engine.
Under the force of the pump to push the oil through the car engine, there will be a pressure because the oil is flowing faster than it wants to be.
Also, your car uses an oil pressure gauge as an indicator to show the value when the oil reaches the proper operating temperature after your vehicle starts.
If there is no or low oil pressure, you will receive the message: oil pressure engine off.
But when it fluctuates while driving, there must be something wrong with other related components, such as the valve, the oil pump, the filter, or more.
Oil Pressure Fluctuating: The Causes
Why is my oil pressure fluctuating? The main reasons can be insufficient oil level, excessive engine heat, poor sending unit, bad RPMs, defective gauge, or faulty oil filter.
The most common and obvious cause is undoubtedly the lack of oil.
Let’s learn more about these causes below.
Insufficient Oil Level
The first thing to come up in your mind should be the lack of oil in the engine. Whenever there is not enough oil, the pump can not work at it best and may push the oil at different pressures.
So the gauge will not point out at a precise reading.
Excessive Engine Heat
Another cause of this problem is the engine heat which also contributes to the thickness or oil viscosity.
Multi-viscosity oils such as 5W-30 are designed to be thin for starting up yet provide 30-grade protection to the engine system at normal operating temperature.
When the engine is hotter or colder than normal, the chemicals that change the engine oil’s viscosity can’t compensate, resulting in a change in oil pressure.
Bad RPMs
If the oil pump fails, it can also cause this problem. An oil pump in your vehicle is a mechanical device turning faster when the automotive engine runs at high RPM and pumps more oil.
Lower RPMs mean slower rotation and less oil pumping. If the processes take place perfectly, the bypass system can help the oil pressure gauge to stabilize.
Yet, displaying a little more oil pressure at a higher RPM is not popular.
Poor Oil Pressure Sending Unit
The bad sending unit is also to blame for the oil pressure gauge fluctuating while driving. This unit is a sensor that reports engine oil pressure to the car’s dashboard.
They can be leaky and allow oil to seep into the electrical connector on the sensor’s side. This triggers the dashboard oil pressure gauge to fluctuate abruptly, regardless of engine speeds.
You may diagnose this problem by checking for oil leakage into the sensor’s electrical connection.
Defective Gauge
The fluctuating oil pressure gauge can also originate from a defective gauge. You can encounter two main types of oil pressure gauges that may be faulty.
First, mechanical types operating with levers and small springs may capture the worn, loose, dirty, or exhibit erratic readings from the road vibrations or engine system.
Another type is electric ones that are easily oxidized due to the sensor activation through a small electrical resistance measurement range.
Thus, this type can get a bit of corrosion causing big changes in the oil readings.
Faulty Engine Oil Filter
A malfunctioning oil filter can also be a culprit of the oil gauge fluctuating when you start up the engine.
You should note that several engines come with an oil filter with a non-return valve. It can prevent oil leakage immediately after the engine is off.
So, an improper oil filter installation may lead to oil draining to the pump when the automotive engine stops. If you start the engine, the oil pressure will remain low for some time.
Blown Head Gasket
Another cause of oil pressure fluctuating while driving is a blown head gasket, especially when the oil pressure problem occurs immediately after the engine warms up.
A damaged head gasket keeps the coolant and oil separate and prevents them from mixing. When the coolant mixes with the engine oil, the engine oil foams, and oil pressure drops.
A foaming engine oil, low-pressure reading, exhaust smoke, and a significant drop in coolant level indicate this problem.
Repair a faulty head gasket to prevent possible damage to other automotive parts because of heating, improper combustion, or lubrication shortage.
Bad Oil Viscosity
If you find the oil pressure fluctuation, it is possible to have a poor oil viscosity. You should use multi-viscosity oil for your engine to ensure the oil viscosity is stable.
However, contaminants, dirt, or others can dilute and degrade the oil over time.
So, using car oil for a long time will cause it to lose its viscosity and lead to a fluctuating pressure gauge.
Is It Normal For Oil Pressure To Fluctuate?
Yes. It’s okay for a car’s oil pressure reading to fluctuate with the automotive engine RPM.
The oil pump connects to the engine and speeds up when the engine revs. This results in higher oil pressure at higher engine speeds.
What to Do If Your Oil Pressure Gauge Fluctuates While Driving?
Examine Oil Level
Checking to determine if the oil level is constant is the first thing you should do. The low oil is the main cause of the fluctuating oil pressure.
You must pull the dipstick out and clean it to identify the oil level. After completing the inspection, reinsert it and pull it out one more time to examine the oil level’s position.
If you detect a low oil level, add a proper amount until it can reach the dipstick’s full line. Once done, restart the engine and see whether the oil pressure is stable. If not, proceed to another solution.
Check & Find Oil Leaks
Let’s say you don’t have time to add the oil to your engine; continue checking and finding the leaks. These leaks can be the root cause of the fluctuating pressure.
Keep an eye on some common places or components, such as the drain plug, oil filter, pan gasket, and front and back seals.
Besides, you need to find the proper solution for fixing this failure to avoid further damage to your vehicle.
Inspect Oil Pump
The next step is to examine the oil pump when your oil pressure fluctuates. Inspect the oil pump by removing the timing belt cover and replacing any worn or faulty parts.
After replacement, restart your auto engine and double-check if the oil pressure is stable.
Should the problem persist, take your vehicle to the automotive shop for a professional mechanic to check and fix it.
Replace the Faulty Sending Unit
Apart from the above solutions, you need to look at the sending unit and change the new one if it’s faulty. Note that the sending unit often comprises tiny tubes that can easily get damaged or clogged.
Find the sending unit’s location on the engine block to replace the faulty one. It’s often near the oil filter housing. Remove the old sending units from the engine block by unscrewing them.
Then, place the new one into the engine block and screw it. Also, reconnect the tubes to the new unit and the oil pressure gauge.
The last thing is to restart the automotive engine and inspect the oil pressure gauge to ensure it functions properly.
And besides the sending unit, remember to change the oil filter (without changing oil) to guarantee the proper oil pressure.
How Can You Read The Oil Pressure Using The Gauge?
Analog oil gauges can only be available on a few newer vehicles and older in-dash models. Readings can be displayed in Bar or PSI, depending on the automotive model, make, and manufacturer.
You can get oil pressure readings on newer vehicles by placing the OBD-2 scanner under the vehicle’s dashboard.
What Are Factors Affecting Oil Pressure Readings?
Worn Engine Components
The worn engine components can affect the oil pressure readings and lead to low oil pressure. If you’re using an old car, this problem often happens with high mileage.
Automotive Oil Viscosity
Besides, oil viscosity plays an important role in the oil pressure readings. The thicker oil can cause higher fluctuating oil pressure.
Auto Engine RPMs
The higher engine speed, the greater the oil pressure.
Oil Temperature In Vehicle
If the oil is hotter, the oil pressure will be higher. So, you should pay more attention to the oil temperature when driving in hot weather.
Oil Filter In System
When the oil pressure is low, it indicates that your vehicle has a clogged or dirty oil filter. So, an oil filter is also an important factor influencing your oil pressure readings.
FAQs
How Can Oil Viscosity Influence Oil Pressure?
It determines how properly your oil pump functions. The oil viscosity is the right measure of how thin or thick your oil is. The thicker oils will result in a higher viscosity, while thinner oils get a lower viscosity.
How Often Should You Change the Automotive Oil?
It also depends on your car’s manufacturer, oil types, and driving habits.
Yet, you should replace the automotive oil every 6 months or every 5,000 miles for conventional oil or every 12 months or 10,000 miles for synthetic oil.
How Much To Pay For Replacing An Oil Pump?
The cost range for oil pump replacement is between $300-$2500, based on what type you choose and where you have it replaced.
Why Does Oil Pressure Fluctuate When You Stop?
The automotive engine doesn’t need too much oil when you brake or stop your vehicle. This is why the oil pressure fluctuates.
Conclusion
The above is everything you should know about oil pressure fluctuating. This problem often happens due to insufficient oil, excessive engine heat, bad sending units, and poor RPM.
Besides, the main culprits can be leaks, poor oil pump, or low oil viscosity. After identifying the root cause, you need to choose the proper solution to fix it.
If you don’t know the main reason, take your vehicle to a professional mechanic for better inspection and repair.
This will help you solve the problem with the oil pressure gauge and give you engine optimal protection.