Bad Oil Pump Symptoms, Causes, and Replacement Cost

The oil pump is one of the most important parts of your car. The main function of the oil pump is to send oil to all the moving parts of the engine while the engine is operating. This oil helps the parts work smoothly and stops them from getting worn out from rubbing against each other. The oil pump also helps to cool down the engine by taking away extra heat. A bad oil pump produces different drivability issues. This article explains the bad oil pump symptoms, causes, and how to test it.

Function of Oil Pump

An oil pump is a mechanical device that is used to circulate oil throughout the engine. It sends oil to the engine’s moving parts like bearings, pistons, crankshafts, and camshafts.

While the engine is operating, the oil pump sends oil through tiny paths inside the engine. But over time, this pump can wear out or get blocked by dirt.

If the pump is damaged, it doesn’t circulate oil efficiently, and your engine may get too hot or stop working. To make sure everything is okay, it’s important to contact a professional mechanic to check the oil pump regularly.

Symptoms of a Bad Oil Pump

When an oil pump goes bad, there are a few signs to look out for. The most common sign is a warning light on your car’s dashboard indicating low oil pressure. Your engine may start to overheat.

Additionally, you can observe that your engine is making more noise than normal. To check for this, you can open the hood while the engine is running and listen for any unusual metallic sounds.

The following are the most common symptoms of a bad oil pump:

1) Low Oil Pressure

Insufficient oil pressure is one of the clear symptoms of a bad oil pump. The oil pump is responsible for maintaining the oil pressure that lubricates and cools your engine’s parts. It pressurizes the oil to help it flow smoothly through the engine’s various components.

With enough oil, the engine’s rotating components stay well-lubricated and can slide against each other without causing harm.

However, if the oil pump is faulty and the oil pressure drops, it leads to insufficient lubrication. This causes the engine components to rub roughly against each other. The first indication of low oil pressure is the low oil warning light illumination on the dashboard. Other effects of low oil pressure include reduced power and potential engine stalling.

Read More: Low Oil Pressure Causes and Symptoms

2) Hydraulic Lifter Noise

The valve-train system in your vehicle relies on hydraulic lifters, along with other parts like valve guides, seals, and pushrods, to ensure smooth engine operation.

For the hydraulic lifters to function properly, they need sufficient lubrication provided by the oil pump. However, if the oil pump fails and oil pressure drops, the hydraulic lifters won’t receive enough oil, resulting in reduced mobility and increased noise during movement.

Insufficient lubrication causes excessive friction, leading to wear and tear, which significantly shortens the lifespan of hydraulic lifters.

3) Noise from the Valve-Train System

The components of the valve-train system also require a proper oil flow to lubricate their metal parts.  

Insufficient lubrication causes friction within the engine’s mechanical parts, resulting in noise within the valve-train system. This is why excessive noise in the valve train can indicate a potential issue with the oil pump in a vehicle.

4) Engine Overheating

An overheated engine is also one of the most common signs of a faulty oil pump. Engine oil serves two important purposes in the engine: lubrication and cooling.

Why is cooling necessary? Well, the engine contains various metal parts that move and create friction. This friction generates heat, and if not controlled, it can cause damage to the engine components.  

Engine oil plays a crucial role by absorbing and dissipating this heat, keeping the components cool. If the oil pump malfunctions, it fails to deliver an adequate amount of oil to the engine, resulting in engine overheating.

You can usually tell when the engine temperature warning light illuminates on the dashboard, indicating that the engine has become too hot. If you observe this warning light, it’s important to pull over and turn off the engine promptly. Allowing the engine to cool down before checking the oil level is a good practice.

Read More: Engine Overheating Causes

5) Noisy Oil Pump

When the oil pump is working properly, it doesn’t make any noise. But when it starts to have problems, it makes a whining and grinding sound as it tries to move oil around the engine.

These sounds are most noticeable when the car is not moving. The reason for these noises is that the gears inside the oil pump have worn out over time.

6) The Vehicle Won’t Start

The latest vehicle models often contain a low oil pressure switch connected to the ignition system. This switch serves as a safety feature that prevents the engine from starting if it detects a malfunctioning oil pump. This is done to prevent the vehicle from potential impairment.

The low oil pressure switch is intended to prevent drivers from driving their cars to a repair shop, as doing so with low oil pressure can lead to costly repairs.

But it’s important to note that this feature is typically found only in newer vehicles. If you’re driving an older car, you’ll need to take your own safety measures to avoid engine damage.

If you continue to drive with insufficient oil pressure for a prolonged period and the engine eventually stops working and fails to crank, it signifies significant issues that may lead to the complete failure of the engine.

Read More: Bad Water Pump Symptoms and Causes

Causes of a Bad Oil Pump

• Wear and Tear: Over time, wear and tear may lead to the failure of the oil pump. This is one of the most frequent reasons why an oil pump may fail.
• Wrong Installation: If the pump is not installed properly, it may cause premature failure. Therefore, you should always hire a professional for your pump installation.
• Low Oil Levels: If you are driving with insufficient engine oil from a long time, it may lead to the failure of the oil pump. Your pump requires a sufficient level of oil to work efficiently, and if it’s always pumping a low amount, it may wear out fast.
• Poor Maintenance: If you don’t change your oil on a regular basis, it may cause the accumulation of dirt in the oil, which may ultimately clog the oil pump. When your pump is clogged, it may work harder and eventually fail.
• Contaminated Oil: If your oil is dirty, it may lead to the failure of the pump.

Oil Pump Location

The oil pump in your vehicle is usually installed inside the oil pan. It is typically located near the oil pan’s top and utilizes a pickup tube to extract oil from the pan and circulate it throughout the engine. In certain engines, the oil pump can also be found near the front of the crankshaft.  

The oil pump is difficult to access because of where it’s located. To reach it, you have to remove the oil pan, which makes the task more time-consuming and challenging. Additionally, for many vehicle models, you’ll need to take off several parts, including the front main cover, which adds to the complexity of the process.

How to Test Oil Pump

• Determine the normal engine oil pressure for your specific car model by referring to the owner’s manual.
• Locate the oil pressure sensor, a small black cylinder under the hood responsible for reading and displaying oil pressure on the dashboard. Use a wrench to loosen the nuts securing the sensor and remove it.
• Obtain an oil pressure gauge, which is a device that measures and shows the oil pressure within the engine. Attach the gauge’s hose to the spot where the oil pressure sensor was first installed, or position the gauge where it can be easily seen from the driver’s seat.
• Start your car’s engine and observe the pressure readings on the oil pressure gauge. Allow the engine to warm up for approximately 12 minutes, and then check the readings again. The pressure reading should be within 10 PSI of the suggested oil pressure mentioned in your vehicle’s manual.
• Test the oil pressure at different RPMs by performing the following steps in a safe, open area: while keeping your vehicle parked, steadily press the accelerator pedal until the engine reaches 1000 RPMs. Perform the same process at 2000 RPM. The oil pressure reading on the pressure gauge shouldn’t deviate over 10 PSI from the ideal pressure specified in the vehicle’s manual.
• If the oil pressure reading doesn’t align with the normal pressures outlined in the manual, it could indicate a potential problem with your oil pump.

Oil Pump Replacement Cost

The cost of replacing an oil pump can range from $280 to $2600, depending on factors such as the specific car model and labor expenses involved. Generally, the replacement requires parts costing around $90 to $620, while the labor costs can amount to $190 to $1980.

In addition to the oil pump itself, which typically costs between $50 and $150, the replacement often necessitates a new oil pan gasket and potentially a new front main gasket.

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