Oil Pressure Drops to Zero While Driving (Causes and How to Fix)

Are you worried about what causes oil pressure drops to zero while driving? Low Oil pressure is not a good sign; it can lead to engine failure.

Are you wondering why oil pressure drops and is it a serious problem? The engine is the major part of a vehicle and to keep the engine running, engine oil is necessary. Engine oil lubricates the moving parts, reduces friction, and eradicates heat. Oil pressure is responsible for the longevity of the engine. Moreover, the oil pressure gauge indicates oil pressure.

Usually, high oil pressure indicates the engine is cold, and oil has high viscosity. However, low oil pressure indicates a significant problem. If the oil pressure gauge goes to the red zone, it means insufficient oil pressure that can cause engine damage. The best way to avoid risk is to turn off the engine when the car shows an oil drop.

Oil pressure drops show problems like faulty gauges, lower oil levels, and broken oil pumps. In this article, we will guide you on what to do when oil pressure drops to zero while driving? Before starting, let’s discuss why oil pressure is vital.

Motor Oil pressure drops

Why is oil Pressure important?

Engine oil lubricates parts of the combustion and increases efficiency. Generally, an Engine

lubricating system majorly depends upon a pump, filter, and greasing line system. The engine oil moves through the lines and builds pressure. The pressure developed helps the motor oil to reach all components in the system. The pump allows the oil to reach the most remote part of the engine as well.

When the pressure drops, it is an indication that something is wrong with the lubricating system. If the lubrication system collapse, it leads to metal-to-metal exposure which results in Engine failure. If the engine is damaged, it is an expensive and time taking process. So, a car needs a visit to a mechanic. Oil pressure drops to zero is not a good sign.

 Causes of oil pressure drops to zero while driving

 Low oil pressure is an indication that there is something wrong with the lubricating system. Let’s look at some causes of low or zero oil pressure.

1. Broken Oil Pump

An oil pump is an essential part of the lubricating system. Oil pumps circulate oil throughout the engine. When a car pump is broken or damaged, the oil pressure drops. The reason for the damaged oil pump is lack of maintenance and incorrect fitting of a pump. Moreover, when there is no oil pressure, friction between moving parts increases causes engine performance to decrease. Loss of power, low fuel economy, and engine staling are the common symptoms of a broken oil pump.

2. Low engine oil 

Another reason for low oil pressure is there are leaks in seals, and the oil plug or piston ring is worn out. You will notice blue smoke coming out from your car exhaust. Secondly, evaporation can cause the oil level to drop. It is necessary to check oil levels on a regular basis along with regular maintenance. When the oil level bot changed regularly, the oil level can drop.

3. Engine Problem

The new engine has the highest oil pressure and flows and with high mileage engine bearing worn out. Wear and tear cause oil to flow faster and decreases oil pressure. Thus, you will face low oil pressure while driving. The solution to this problem is changing the bearing. If the problem exists, it needs engine replacement.

4. Damaged oil Pressure gauge

Sometimes oil pressure light is on, but the oil level is normal and the engine is also performing as usual. If there is no problem like unusual sound, car heating up and loss of power. In this case, the reason is a damaged oil pressure gauge or sensing unit. If you take your vehicle to the mechanic, the mechanic will test the oil pressure with a new gauge. If the reading is normal, replace the sensor. The problem is that the defective oil sensor gives a false reading.

5. Clogged filter

Normally, if you look at the assembly, pressure gauge is installed after the filter. When the filter became clogged, the valve doesn’t operate properly. A clogged filter leads to extended oil and thus result in poor combustion. A clogged filter is due to leaks therefore needs replacement.

 How to fix oil pressure while driving?

A drop in engine oil pressure causes damage to the car. It can lead to engine failure. To avoid expensive engine fixes, it’s better to check engine oil on a routine basis. Route checkups prevent major problems. Change in viscosity of oil can cause damage to the oil pump. The thicker the oil, the more the pressure is on the oil pump. Keep a check for external oil leaks; it can cause oil drops.

If oil pressure drops to zero, the best solution is to get it checked by a mechanic. Majorly the problem is the broken oil pump. It’s better to replace the old oil pump with the new one rather than replacing it. Regular maintenance can avoid oil leakage problems.

 What causes oil pressure to drop after the engine warms up?

When the car startup, it takes 20 minutes for a car to build oil pressure. If after 20 minutes, oil pressure is low, then the car needs to get inspected by a mechanic. It is a key indication of a faulty oil pump. Generally, this is not a good sign, it needs attention. An engine requires lubrication to operate effectively. Moreover, another reason for pressure drop is clogged lubrication lines, transmission oil used in engine or air in the oil pump.

 What causes oil pressure to drop to zero at idle?

Suppose you notice low oil pressure at idle. It means that the engine has a low oil level. The reason behind zero oil pressure at idle is a defective oil pump. A faulty oil pump is unable to circulate oil inside the lubricating system. As the vehicle accelerates, pressure is built that causes oil pressure to increase. Sometimes high temperature causes oil pressure to drop. Oil pressure gauge goes up and down while driving.

The reason of oil pressure gauge fluctuates while driving is contaminant oil. According to physics, thicker liquids require more pressure. However, thinner liquid requires less. If the oil has impurities, it requires an oil pump to build more pressure.  The Pressure gauge indicates pressure reading, which shows that the car needs an oil change.

FAQ (Frequently Asked Question)

1. Will a car run with Zero oil pressure?

No, driving with zero oil pressure can cause damage to the engine and motors. Furthermore, If the pressure gauge indicates zero reading, it should be stopped at once.      

2. What are the signs of a bad oil pressure sensor?

Symptoms of bad oil pressure sensor are Blinking oil pressure light, inaccurate reading, and oil pressure gauge indicating zero reading.

3. Can too much oil cause low oil pressure?

Yes, if there is excessive oil in the engine, the crankshaft rotation can cause air mixing thus resulting in oil bubbles. It creates problem for the oil pressure pump to operate effectively. Moreover, the result is low oil pressure.

4. Is it OK to drive with a bad oil pressure sensor?

Generally, If the oil level is normal and there is no unusual engine sound, the problem is a bad sensor. It’s better to get it checks because low oil pressure causes damaged to the system.


Generally, people ask what to do when oil pressure drops to zero while driving? Oil pressure turning to zero can cause damage to the engine. Lubrication system, lubricate moving parts of the engine. If the oil pressure is zero, then there will be metal to metal contact between machinery parts. Thus, this problem requires immediate care. It is better to consult a mechanic.


Mr. Rubel is an Engine Mechanic. He has more than 15 years’ experience on repair and maintenance of different kinds of vehicles. He is also providing training to mechanics and works as a Senior Mechanic of a well-known organization. He is sharing his knowledge to support the car lovers to solve the vehicle issues.

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