Low Oil Pressure: Causes and Symptoms

Dashboard oil pressure warning light indicating low oil pressure, with a mechanic holding a dirty, used oil filter

Low oil pressure in a car can be a serious issue that leads to significant engine damage if not addressed promptly. Here we discuss the most common causes and symptoms of low oil pressure. We hope that this information helps you better understand the importance of maintaining proper oil pressure and encourages you to take proactive measures to protect your vehicle and engine.

Importance of Oil Pressure

Maintaining adequate oil pressure is critical for the proper functioning and longevity of an engine. Oil pressure ensures that oil (which acts as a lubricant) is continuously pumped through all engine components. This process is essential because the oil forms a protective film that reduces friction and wear on metal surfaces.

When oil pressure drops, it signifies insufficient circulation of oil. This inadequate lubrication results in metal-to-metal contact, causing increased friction and heat generation. Such conditions can lead to overheating and accelerated wear of critical components, including bearings and pistons. Prolonged low oil pressure can ultimately result in major engine damage or even a seized engine.

Ensuring consistent oil pressure is therefore essential to avoid these mechanical failures and to maintain engine logivity. Regular monitoring and maintenance of the oil pressure system are key practices for any vehicle owner or technician.

Common Causes of Low Oil Pressure

Low oil pressure can be caused by several factors, including low oil levels, a faulty oil pump, or a clogged oil filter. Below we detail the most common causes of low oil pressure and offer recommendations for each issue.

Low Oil Level

The most common cause of low oil pressure is simply not having enough oil in the engine due to leaks or burning oil. Regularly check the oil level and top up as necessary. If you frequently need to add oil, have your car inspected for leaks.

Incorrect Oil Viscosity

Using the wrong oil viscosity for your engine can affect oil pressure. Thinner oil (lower viscosity) might not build sufficient pressure, while thicker oil (higher viscosity) can create too much resistance which makes it difficult for the oil to flow. Always use the oil grade recommended by the manufacturer.

Worn Engine Bearings

Over time, engine bearings wear out, increasing the clearance between moving parts and reducing oil pressure. This is more common in high-mileage engines. If you suspect worn bearings, have a mechanic inspect and possibly replace them.

Clogged Oil Filter

An oil filter that is clogged can restrict oil flow and reduce oil pressure. It's important to change the oil filter with every oil change and use quality oil filters to avoid clogging. Here are the signs that indicate you have a clogged oil filter.

Faulty Oil Pump

The oil pump circulates oil through the engine. If it malfunctions, oil pressure drops. Regular oil changes can help prevent premature oil pump failure.

Other Causes

Engine Sludge: Sludge forms when the oil is not changed regularly. It can clog passages and restrict oil flow, causing oil pressure issues. Follow the manufacturer’s recommended oil change intervals and use quality oil to prevent sludge formation.

Contaminated Oil: Mixing of oil with fuel or coolant due to internal engine issues can reduce oil's effectiveness and lower oil pressure

Sensor Issues: Mixing of oil with fuel or coolant due to internal engine issues can reduce oil's effectiveness and lower oil pressure

Symptoms of Low Oil Pressure

Illuminated Oil Pressure Warning Light: Most cars have a dashboard light that illuminates if the oil pressure is low. This is a warning that you shouldn't ignore.
Unusual Engine Noise: Low oil pressure can cause increased engine noise due to metal components rubbing against each other.
Engine Performance Issues: Reduced lubrication can lead to problems like engine hesitation and even engine failure.
Decreased Oil Level: Frequently needing to top up the engine oil can be a sign of low oil pressure and potential oil leaks.

What to Do if You Have Low Oil Pressure

Pull over safely as soon as possible. Turn off the engine and don't attempt to restart it. Check your oil level. If the oil level is low, add oil if you have some available. However, a low oil level is just a symptom, not the root cause. If you don’t have oil, call for a tow truck. Don't try to drive your car with low oil pressure, as it can cause engine damage. Finally, have your car inspected by a mechanic. A mechanic can diagnose the cause of the low oil pressure and recommend the necessary repairs.

Addressing low oil pressure promptly can prevent severe engine damage. Regular maintenance, including timely oil and filter changes, using the correct oil viscosity, and monitoring for leaks or unusual noises, can help maintain proper oil pressure and ensure the longevity of your engine. Driving with low oil pressure is not recommended, so pull over safely and turn off the engine immediately if the oil warning light comes on. For more detailed diagnostics and repairs, consult a professional mechanic.

Questions? We're here to help. Reach out the FRAM specialists for product and maintenance support.

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