Here’s why oil pressure drops when accelerating

During driving, one of the important gauges to monitor, in addition to the fuel gauge, is the oil pressure gauge. Your car engine requires an adequate supply of oil to lubricate its parts, preventing overheating and subsequent car damage.

The oil pressure should rise within the normal range when the car accelerates. This is because increased motor rotation (higher rpm) during acceleration spins the oil pump faster, creating a higher oil pressure

However, when the oil gauge drops during acceleration, this indicates several potential problems in your car. The most common diagnosis is low oil-level volume. During acceleration, the oil is pushed to the back of the oil pan, causing the oil pump to draw in air, which drops the oil pressure.

With reduced oil quantity, the oil pump cannot lubricate the accelerating engine, which increases friction between the rapidly moving parts. A lubricant-starved engine can overheat within a short time, leading to car breakdown.

Other causes of oil pressure gauge drop during acceleration

Bad oil gauge

In addition to low oil volume, a drop in oil pressure can indicate a faulty oil gauge. The oil gauge monitors the oil pressure entering the engine at all times.

A sensor is usually attached to the inside of the oil pump, which detects the amount of pressure and relays this information to the driver. However, when damaged, the oil pressure gauge displays faulty readings, such as low pressure during acceleration.

Bad connecting rod, camshaft, or crankshaft bearings

Worn-out bearings of the crankshaft, the connecting rod, and the camshaft can cause an oil pressure drop. Due to the high heat conditions of the engine, bearings are prone to wear and tear.

When worn, the bearings increase their clearance, thus reducing the oil flow restriction. The high-pressurized oil leaks from the sides of the bearings, where clearance has been created.

With the reduction in the volume of the oil, the pressure subsequently reduces, which causes the oil pressure gauge to record low reading.

Faulty oil pump

Another reason for the oil pressure drop during acceleration is a defective oil pump. A faulty oil pump will fail to generate the amount of pressure needed by the accelerating engine, resulting in a low-pressure gauge reading.

Moreover, a pump with a pressure relief valve that sticks releases the pressure formed inside the oil pump, causing a sharp decline in oil pressure.

A defective pump is quite easy to diagnose as the valve train system produces a lot of additional noise. Additionally, the temperature gauge will record higher temperatures which signal the oil pump’s failure to cool the engine.

How to fix the oil pressure gauge drop

Various solutions are available depending on the cause of the oil pressure drop. 

  • Foremost, you can rectify the low oil volume issue by regularly checking your car’s oil level using a dipstick. You can top up the oil with a high-quality synthetic oil brand if found under the recommended level. A car with low oil levels requires around one liter to top up. A 5-qt bottle of synthetic engine oil costs about $30. 
  • Likewise, to fix the faulty oil pressure gauge, a replacement is needed. The cost of a new sensor and labor will cost between $50 and $250, depending on the sensor brand, car model, and type of labor. 
  • The worn-out engine bearings can be replaced during routine car maintenance. Depending on the car model, market price, and location, engine maintenance, including bearing replacement, can cost from $2,000 to $5,000. Although expensive, a new set of bearings can last up to eight years, provided the vehicle is properly maintained. 
  • Regarding the defective oil pump, once diagnosed as the problem cause, the pump should be immediately replaced. The cost of a new pump plus labor ranges from $100 to $300, depending on the car model. 

Final thoughts

When driving, paying attention to the car gauges, particularly the oil pressure gauge, is important to ensure the car is functioning properly.

The oil pressure gauge should raise and lower depending on the vehicle’s rpm (revolutions per minute). Once you observe abnormalities in the oil pressure gauge indication, such as dropping significantly during acceleration, conduct an immediate car checkup to diagnose the issue.

The potential problems can range from low oil volume to a defective oil pump and worn-out engine bearings. Addressing these issues at their onset can avert more serious problems such as engine overheating and the eventual car breakdown.

Furthermore, the cost of fixing these problems is much lower and saves you time that would have otherwise been spent in the garage.

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