Oil Level Sensor Problems: Symptoms and Fixes

What Is the Oil Level Sensor?

The oil level sensor monitors your vehicle’s engine oil. Think of it as an electronic dipstick.

When the engine oil level becomes too low, the sensor will either close a circuit or transmit an electronic signal to a module (BCM, PCM, etc.). As time passes, this part can fail prematurely.

Oil level sensors vary in design and some have been around for decades. Some oil level sensors simply have a small float capsule with metal contacts that close a circuit; others, such as the oil level sensors made by Hella, are much more advanced.

Hella makes an oil level sensor that is a very complex packed ultrasonic level unit including an integral module with several chips and a processor that has written algorithms to measure engine oil temperature as well as oil level, measuring acceleration, oil sloshing, average levels, etc.

Bad Engine Oil Level Sensor Symptoms

A bad oil level sensor can cause problems for the engine and the rest of your vehicle. Here are some of the most common symptoms of a malfunctioning sensor:

Wrong oil level reading

Perhaps the most common symptom of a bad oil level sensor is when it sends incorrect information to the PCM.

When the engine oil level in the crankcase has dropped to critically low levels, the oil level sensor will transmit a warning signal to the control module. The PCM will then activate the engine oil level low warning light.

If its components wore out or were damaged, the engine oil level sensor might make mistakes when measuring the oil level. Even if there’s enough lubricant on hand, a bad sensor might think the engine oil is about to run out. It will send the warning signal to the PCM, which will turn on the engine oil level low warning light.

Check your vehicle’s actual oil level if you see this light come on. If you inspect the dipstick and see that the oil remains above the line that marks the low oil level, there might be something wrong with the oil level sensor.

Oil light turns on sometimes

The next common symptom of a bad oil level sensor is the intermittent activation of the engine oil level low warning light. The oil level sensor also turns on when you start your vehicle. If the sensor detects a low oil level during start-up, it will inform the PCM, which will activate the engine oil level low warning light.

However, a damaged or bad engine oil level sensor might not immediately transmit the warning signal to the PCM. Or it can trigger the warning light despite a normal oil level. If the oil level low warning light illuminates while you’re driving, long after you’ve started the engine, there’s a possibility that the sensor might have failed and needs replacement.

This symptom can also be caused by other engine oil-related issues, such as low oil pressure caused by a bad oil pump or blocked oil lines. Whatever the underlying cause for the intermittent illumination of the oil level low warning light, you should check your car as soon as possible.

Engine fails to start

Did your vehicle refuse to start despite your best efforts? While the oil level sensor doesn’t directly control the engine like the PCM does, a faulty sensor can potentially cause failed starts on some platforms.

If the sensor transmits incorrect data about the oil level, it might cause the PCM to mistakenly log an OBD code that will forcibly put the engine in safe mode. Until the incorrect OBD code gets cleared, the PCM will prevent the engine from starting in an attempt to prevent it from running dangerously.

Check engine light illuminates

When something goes wrong in the engine, the check engine light often turns on to warn you about the issue. A bad oil level sensor can also trigger this light. When the sensor is damaged or worn-out, it can accidentally set off the check engine light by sending an inaccurate message about the engine oil level.

More About the Oil Level Sensor

The oil level sensor is usually found in the oil pan. The simple switches may be located in the side of the oil pan, but the more complex sensors will be mounted directly in the bottom of the pan in a recessed area to prevent road damage to the sensor.

Don’t mistake the oil level sensor for the oil pressure sensor. The latter measures the pressure exerted by the oil flowing through the engine.

What Does the Oil Level Sensor Do?

The oil level sensor is a float switch or electronic component that responds to the change in amount of the engine lubricant in the oil pan.

On the simpler sensors, the lubricant level in the oil pan drops along with the float as the engine consumes oil while running. The float switch turns on when the engine oil reaches a dangerously low level. The engine oil level sensor will then send a warning signal to the PCM, which activates the oil level warning light on your vehicle’s dashboard.

Can You Drive With a Bad Oil Level Sensor?

It depends on the severity of the problem. In most cases, you can keep driving your vehicle without a working oil level sensor. The sensor is a warning device, so it doesn’t directly affect the engine’s operation. Don’t neglect checking your engine oil the old fashioned way even if your vehicle does have an oil level sensor.

However, if the engine oil level sensor triggers an OBD code that puts the engine in safe mode, your vehicle will be limited to extremely slow speeds to reduce the risk of overheating. You should replace the bad sensor and clear the PCM or ask a trusted mechanic to check your vehicle.

How Much Does a Replacement Oil Level Sensor Cost?

A replacement oil level sensor can cost anywhere between $10 and $320. The price can vary based on the sensor’s brand and your vehicle’s year, make, and model.

Finding A New Oil Level Sensor For Your Vehicle

Driving with a faulty oil level sensor is dangerous because it could display incorrect oil readings and cause problems like the engine struggling to start. Fortunately, you easily get a replacement oil level sensor at an unbeatable price from CarParts.com.

The best part about searching for replacement parts is that you don’t have to leave your house. To find a new oil level sensor for your vehicle, all you need to do is visit CarParts.com. Input your vehicle’s year, make, model, and engine into the selector to see a vast array of compatible parts.

Our warehouses are strategically located all over the US to you get your order within a few days. If you have questions, don’t hesitate to contact our round-the-clock customer support team.

Don’t wait until your oil level sensor becomes unresponsive before getting it replaced. Check out our collection of high-quality oil level sensors now at CarParts.com.