Oil Pressure Drops When Idle [Causes & Fixes]

The oil pressure in an engine is a critical component that ensures the proper lubrication and cooling of the engine’s moving parts. 

When the oil pressure drops, it can be a sign of an issue within the engine’s oil system that requires immediate attention. 

One common scenario where this may occur is when the engine is idling. 

In this blog post, we will explore the reasons oil pressure drops when idle and what can be done to address the issue. 

car oil pressure drops

What Does Oil Pressure Drop at Idle Mean?

When the oil pressure drops when the engine is idle, it usually indicates that there may be an issue with the oil system. 

Just like said earlier, oil pressure is an essential aspect of your vehicle’s engine performance. It is the measure of the pressure of the oil that circulates throughout the engine. To lubricate and protect its moving parts. 

The oil pressure in the engine lubricates the moving parts and ensures that they are properly cooled.

One common scenario where oil pressure drops are when the engine is idle. This could occur when you are waiting at a stoplight or stuck in traffic, and you notice that the oil pressure gauge is reading lower than normal.

A drop in oil pressure can be an indication of a problem within the engine, and it is crucial to understand the underlying causes and potential consequences.

What is Considered Normal Oil Pressure at Idle?

The normal oil pressure at idle can vary depending on the model of the vehicle and the type of engine. However, most engines should have an oil pressure reading of around 20 to 30 psi (pounds per square inch) at idle when the engine is warm and operating correctly.

If the oil pressure at idle is consistently below this range, it may indicate that there is an issue with the engine’s oil system. Such as a clogged oil filter, worn-out oil pump, or low oil level.

It is important to address low oil pressure promptly. To avoid damage to the engine’s moving parts and prevent costly repairs.

On the other hand, if the oil pressure at idle is consistently above the normal range, it may indicate that the engine’s oil pressure relief valve is not working correctly. This could lead to excessive wear and tear on the engine’s components and may require immediate attention.

Reasons For Low Oil Pressure When Idle

Several factors related to the engine’s oil system can cause low oil pressure at idle. Here are some common reasons for low oil pressure at idle:

1. Low Oil Level

If the oil level is too low, the oil pressure may drop below the recommended range. The oil level in the engine plays a crucial role in maintaining the oil pressure. 

The oil pressure is a result of the oil being pumped through the engine and maintaining a certain level of pressure.

When the oil level is low, the oil pump may struggle to maintain the required pressure. Which can cause the oil pressure to drop below the recommended range.

Oil leaks or burning oil can cause a low oil level. Therefore, it’s important to check the oil level regularly and maintain it at the recommended level.

If your oil level is consistently low, it’s important to identify the cause of the low oil level. To address any potential issues before they cause serious engine damage. Ignoring a low oil level can result in costly engine repairs or even engine failure.

2. Worn-out Oil Pump

The oil pump is responsible for circulating oil throughout the engine. Over time, the oil pump may wear out or become damaged, reducing its ability to maintain the required oil pressure.

When an oil pump is worn out, it may not be able to function as effectively as it did when it was new. This can lead to problems like engine overheating or increased wear and tear on engine components.

In extreme cases, a worn-out oil pump can even cause engine failure.

Factors that Cause the Wear and Tear of an Oil Pump

  • Prolonged use of the engine, 
  • Exposure to extreme temperatures, 
  • Contamination of the engine oil with dirt or debris.

3. Clogged Oil Filter: 

The oil filter removes contaminants from the oil. As time goes on, the oil filter can become clogged with these contaminants, which can restrict oil flow and ultimately lead to low oil pressure.

Several factors can contribute to the clogging of an oil filter, including prolonged use of the engine, exposure to extreme temperatures, and poor quality or contaminated engine oil. 

Regular oil changes and filter replacements can help prevent the buildup of contaminants in the oil filter and ensure that the engine remains properly lubricated.

4. Faulty Oil Pressure Sensor 

The oil pressure sensor is an important component of an engine’s lubrication system that sends a signal to the vehicle’s onboard computer to display the oil pressure gauge on the dashboard. If the oil pressure sensor is faulty, it can give inaccurate readings, causing confusion and potential damage to the engine.

A faulty oil pressure sensor can lead to several issues. For instance, it may cause the oil pressure gauge on the dashboard to show incorrect readings, indicating that the engine has low or high oil pressure when it does not. 

This can lead to unnecessary worry and confusion for the driver, as well as potential damage to the engine if the issue is not addressed.

Additionally, a faulty oil pressure sensor can cause the onboard computer to display warning lights or error messages, which can be a distraction for the driver and potentially mask other important issues with the vehicle.

Factors that Contribute to a Faulty Oil Pressure Sensor

  • Wear and tear over time
  • Exposure to extreme temperatures or moisture
  • Damage from external factors

5. Low-quality or Incorrect Viscosity Oil

This can have a great impact on an engine’s oil pressure, and its overall performance. Therefore, make sure to use the right oil to ensure optimal engine performance and to prevent issues such as low oil pressure.

Viscosity refers to an oil’s resistance to flow. The viscosity of oil can vary based on factors such as temperature, pressure, and additives. If oil with the incorrect viscosity is used, it may not properly circulate throughout the engine, resulting in low oil pressure.

Low-quality oil may contain contaminants that can clog the oil filter or damage engine components. Also, it may not properly lubricate engine components, which can cause increased wear and tear on the engine and ultimately result in low oil pressure.

How to Fix Low Oil Pressure At Idle

If you notice that the oil pressure drops when idle, it’s necessary to address the issue promptly to prevent damage to the engine. Here are some steps you can take to fix oil pressure drops when idle:

1. Check the Oil Level

Ensure that the oil level is at the appropriate level. Low oil levels can cause low oil pressure. If the oil level is low, add the type and amount of oil as recommended by the vehicle manufacturer.

2. Check for Leaks

Look for signs of oil leaks in the engine compartment, such as puddles under the vehicle or oil on engine components.

Leaks can cause a drop in oil pressure, as the oil is not properly circulating through the engine. If you detect any leaks, have them fixed by a qualified mechanic.

3. Check the Oil Filter

To inspect the oil filter, you can consult the vehicle owner’s manual or have a professional mechanic inspect it. If the oil filter is clogged or dirty, it should be replaced as recommended by the vehicle manufacturer.

It’s essential to follow the recommended oil and filter change intervals to prevent engine damage and ensure optimal engine performance.

4. Check the Oil Pump

A worn-out or damaged oil pump can lead to low oil pressure. In some cases, a worn-out oil pump may be able to be repaired or rebuilt. In other cases, it may need to be entirely replaced to ensure safe and reliable engine operation.

5. Check the Oil Pressure Sensor

 A faulty oil pressure sensor can give inaccurate readings and cause low pressure. Have the oil pressure sensor tested by a qualified mechanic to determine if it needs to be repaired or replaced.

Regular maintenance of the oil pressure sensor can help identify and prevent issues before they become more severe.

Using the recommended oil type and viscosity per the vehicle manufacturer’s specifications can help ensure proper oil circulation and prevent low oil pressure.

7. Consider Engine Flush

If there is a significant buildup of sludge or deposits in the engine, an engine flush may be necessary to remove them and restore proper oil circulation. Have the engine flush performed by a qualified mechanic.

How Much Oil Pressure is Too Low?

The ideal oil pressure for an engine at idle will depend on the manufacturer’s specifications and the type of engine. 

An average oil pressure ranges between 20 to 30 psi. Therefore, anything less than 20 PSI is regarded as too low. If the oil pressure in the engine is inadequate, there won’t be enough oil to lubricate the moving parts.

Read: Car is Revving In Park [What it Means]


A drop in oil pressure when idle can indicate a problem with the engine’s lubrication system. There are several potential causes of low oil pressure at idle, including a low oil level, a clogged oil filter, a worn-out oil pump, a faulty oil pressure sensor, and using the wrong type or viscosity of the oil.

Maintaining proper oil pressure is crucial for the long-term health and performance of your engine. So, it’s necessary to take action as soon as possible if you notice any warning signs.

Regular maintenance, such as oil changes and filter replacements, can help prevent low oil pressure.

Therefore, when you notice low oil pressure when idle, it’s essential to have your vehicle inspected by a qualified mechanic to diagnose and address the underlying issue.