If you have the little ‘oil can symbol’ lit up on your dashboard, it usually means your engine isn’t getting enough oil pressure — and that’s something you shouldn’t ignore.
Without proper oil pressure, engine parts don’t receive the necessary lubrication, resulting in friction, overheating, and potential damage over time.
So what exactly causes low oil pressure?
And how can you prevent it from becoming a costly repair?
In this guide, we’ll walk you through the eight main reasons your oil pressure drops, what signs to look out for, and the best ways to fix it.
This Article Contains:
- Why Is Oil Pressure Important?
- 8 Most Common Causes of Low Oil Pressure
- 7 Warning Signs That Indicate Low Engine Oil Pressure
- How Can You Fix Low Oil Pressure Issues?
- 3 Low Oil Pressure FAQs
Let’s dive in.
Why Is Oil Pressure Important?
Oil pressure plays a key role in keeping your engine running smoothly. It ensures that motor oil reaches every moving part, providing the lubrication needed to reduce friction and wear.
Oil pressure is created when the oil pump pushes oil through the engine faster than it would naturally flow, maintaining a steady supply to all critical components. A pressure relief valve regulates this flow to prevent excessive pressure that could harm the engine.
Simply put, motor oil can’t do its job effectively without proper oil pressure. When pressure drops, lubrication weakens, leading to reduced oil efficiency, poor engine performance, and lower fuel economy.
Now that we understand its importance, let’s look at what causes engine oil pressure to drop.
8 Most Common Causes of Low Oil Pressure
Since motor oil relies on steady pressure to lubricate all moving engine parts properly, it’s crucial to monitor your oil pressure readings. If your oil pressure warning light comes on, one or more of the following factors could be responsible:
1. Low Oil Level Due to Leaks
When oil drops below the minimum dipstick mark, the pump can’t build enough pressure to lubricate the engine properly. This can happen due to the presence of degraded oil in the system or oil leaks.
An oil leak often occurs around gaskets, seals, the oil pan, or a loose filter, slowly reducing oil levels. If your oil pressure light is on, you’re frequently topping off the oil, or you notice oil spots under your car, it’s time to have it checked by a mechanic.
2. Incorrect Oil Viscosity (Too High or Too Low)
Oil viscosity refers to how easily engine oil flows at different temperatures.
It’s labeled in the “XW-XX” format, where “W” stands for winter, indicating how the oil behaves in cold weather (0°F). The lower the number before the “W,” the better the oil flows in cold starts. The number after the dash represents how thick the oil stays at high temperatures (212°F).
For example, 5W-30 oil flows more easily in cold conditions than 10W-30, but both perform similarly once the engine is hot.
Using the wrong viscosity oil can lead to issues with oil pressure. Oil that’s too thin (low viscosity) flows too easily, reducing resistance and triggering a low-pressure reading.
In contrast, thicker oil (high viscosity) can restrict flow through the pump, limiting lubrication and also resulting in low oil pressure.
3. Dirt, Debris, or Sludge in the Pickup Tube
A buildup of dirt or sludge in the pickup tube — the oil passage that carries oil from the pan to the pump — can also cause low-pressure readings.
When debris blocks the tube, oil flow to the pump is restricted, leading to reduced pressure. This can cause the oil pressure warning light to illuminate even if other components are functioning properly.
4. Faulty Oil Pump
If your oil level reads between “Add” and “Full” but the engine is unusually noisy, the oil pump may be failing. A worn or damaged pump can’t generate enough pressure, often due to an internal oil leak or wear.
In such cases, replacing the failing oil pump is usually the only way to restore normal oil pressure.
5. Clogged Oil Filter
In most engines, the oil pressure gauge is located after the oil filter and the pressure relief valve.
If the oil filter becomes clogged or heavily contaminated, it can restrict oil flow, leading to oil starvation. This reduced flow leads to a drop in oil pressure, which is indicated on the gauge or by an activated low oil pressure warning light.
NOTE: A clogged filter is often the result of old oil. It may also be caused by some water and/or soot contamination in the relief valve. Get an oil change ASAP to reset the oil light warning.
6. Faulty Oil Pressure Sensor or Gauge
The oil pressure sensor and gauge work together to monitor and display your engine’s oil pressure. However, if either component malfunctions, it can send false readings or fail to alert you when pressure is actually low.
If the low oil pressure light comes on but the engine runs smoothly without any unusual noise, the issue could be with the sensor or the oil pressure gauge rather than the system itself.
7. Exposure to Extreme Temperatures
Extreme cold or hot temperatures can affect how your engine oil performs.
In cold weather, oil thickens and flows more slowly, making it harder for the pump to circulate and causing temporary low pressure during startup. In hot weather, oil thins out, which can reduce pressure and limit protection against engine wear.
8. Engine Damage or Wear
While not the most common cause, engine wear can lead to low pressure, particularly in older or high-mileage vehicles.
As components like bearings and pistons wear down, the gaps between them widen, allowing oil to flow more freely and reducing overall pressure. This wear can also cause the engine to consume more oil than usual, further lowering oil levels over time.
But how can you tell if your oil pressure has dropped?
Let’s find out.
7 Warning Signs That Indicate Low Engine Oil Pressure
Here are some low oil pressure symptoms to watch out for:
- Lit oil pressure light: In most vehicles, this is the first sign of an oil-related issue. A yellow light typically indicates it’s time for an oil change, while a red oil light indicates a severe drop in pressure that requires immediate attention.
- Decreased engine performance: If your engine feels weak, stalls, or uses more fuel than usual, low oil pressure could be the cause. Insufficient oil pressure prevents proper lubrication, making the engine work harder and lose power.
- Unusual engine noise: A knocking or rattling noise means metal parts are rubbing together without enough lubrication, which can damage the engine.
- Burning oil smell: If your cabin smells like burning oil, it could mean there’s an oil leak. Leaking oil drips onto hot engine parts and burns, creating that odor.
- Excessive oil consumption: If you need to top off your oil frequently, it may indicate low oil pressure. Worn piston rings, valve seals, or an internal oil leak can cause your engine to burn or lose oil faster.
- Blue smoke from the exhaust: Due to insufficient oil pressure, engine oil can seep into the combustion chamber, producing blue smoke. This means your engine is burning oil, which can damage the catalytic converter if ignored.
- Engine overheating: While overheating doesn’t always mean low oil pressure, it often indicates an oil-related issue. If you notice smoke coming from under the hood, have your oil checked right away.
Next, let’s go over what you can do to fix problems caused by low oil pressure.
How Can You Fix Low Oil Pressure Issues?
Here’s how you can address and prevent oil pressure problems:
- Maintain sufficient oil levels: Regularly check your oil with the dipstick and keep it between the minimum and maximum marks. Use the manufacturer-recommended oil grade to ensure the correct viscosity and steady pressure.
- Replace a faulty oil pump: A failing oil pump can’t circulate oil efficiently, leading to pressure loss. If diagnostics confirm the pump is malfunctioning, have it replaced immediately. Regular inspections can also help detect pump wear before the problem worsens.
- Repair or replace worn bearings: Worn engine bearings can disrupt oil flow and reduce pressure. Depending on the severity, this may require replacing the bearings or performing an engine overhaul to restore proper lubrication.
- Get regular oil filter changes: A clogged oil filter restricts the flow of oil, lowering pressure and allowing contaminants to accumulate. That’s why regular oil changes and filter replacements are necessary to keep the oil circulating freely and prevent oil leaks.
- Replace the faulty oil pressure sensor: If your low oil pressure light remains on or pressure readings appear incorrect, the sensor may be defective. Testing and replacing it ensures that you receive accurate readings and timely alerts when real issues arise.
Have more questions?
We’ve got you covered.
3 Low Oil Pressure FAQs
Here are the answers to some commonly asked questions about low oil pressure:
1. How Can You Check the Oil Pressure?
Checking for high or low oil pressure can be a challenging task. If you don’t have experience working with automotive parts, it’s best to leave the job to a mechanic.
Here’s a quick walkthrough of how they’ll check the oil pressure:
- Lift the front end of your vehicle and locate the engine oil pressure sender or oil pressure sending unit, which is typically near the sump on the engine block.
- Place an oil pan underneath the engine to catch oil spillage, and remove the electrical connector from the engine oil pressure sender.
- Remove the oil pressure sending unit from the engine block using the right socket (usually 1 1/16”) and mount the tester. You can also connect the test gauge to one of the oil cooler lines.
- Let the engine idle for 5 minutes, or until it reaches its operating temperature. Maintain the required RPM as per the engine manual.
- Take the oil pressure readings and check if you have low or high oil pressure.
2. Is It Safe to Drive with Low Oil Pressure?
No, it’s not safe to drive with low oil pressure. When oil pressure drops, your engine isn’t properly lubricated, which increases friction and accelerates wear.
You might notice reduced power or sluggish acceleration as performance declines. Continued driving in this condition can cause severe engine damage or even a complete engine seizure.
If you notice low oil pressure warning signs, it’s best to pull over and have your vehicle inspected immediately. Regular oil changes and timely maintenance are the most effective ways to prevent expensive repairs.
3. How Much Does It Cost to Fix a Low Oil Pressure Problem?
Repair costs for low oil pressure can vary widely. Depending on the part that’s failing and your vehicle type, here’s what you might have to pay:
- Oil pickup tube and screen replacement: $10 – $175
- Engine oil and filter change: $75 – $200
- Oil pressure sensor replacement: $130 – $370
- Engine rod bearing replacement: $800 – $3,400
- Oil pump replacement: $1,200 – $1,630
Stay Ahead of Engine Troubles with AutoNation Mobile Service
Low oil pressure can lead to severe problems, including engine overheating, premature wear, and reduced performance.
It’s always smarter to fix the oil pressure issue before it leads to expensive engine damage. Whether it’s a bad oil pressure sensor or a failing pump, AutoNation Mobile Service has you covered.
We’re a mobile car maintenance solution available seven days a week, offering upfront pricing and a 12-month, 12,000-mile warranty on all repairs.
Fill out our online form today to get a free quote and have your oil pressure issues fixed right from your driveway.