5 Symptoms Of a Bad Oil Pressure Sensor (Replacement Cost)

A bad or failing sensor would start showing various strange signs, and if ignored, could cause serious damages to the car. But what are the symptoms of a bad oil pressure sensor?

A bad or failing oil pressure sensor would cause the oil pressure warning light to keep coming on and off intermittently, which can, over time, lead to more expensive damages.

Most drivers pay less attention to their engine’s oil pressure sensor; some may even remove it for quite different reasons. But the truth remains that oil pressure sensors perform a very important task – notifying you when to refill oil or check your engine’s oil level.

So, it is important you know these symptoms, and act very fast when you start noticing any of them.

Symptoms Of a Bad Oil Pressure Sensor

It is important to note oil pressure sensor is the same as the oil pressure switch; the words – sensor and switch – are used interchangeably throughout this article.

Now, let’s get down to the main deal of the day.

1. Intermittent Oil Pressure Warning Light

This is majorly what shows your car has a faulty oil pressure sensor. The function of this sensor, or switch, is to detect when the oil pump isn’t pushing enough oil into the engine, and then notify the oil pressure computer to activate the warning light on your dashboard.

So, basically, if the sensor is good, whenever the oil pressure light illuminates on your dashboard, it’s a sign that you should go for an oil change, or refill the oil reservoir. But when this light keeps coming on and off (blinking), it’s simply a sign of a falling oil pressure switch.

The intermittent blinking occurs because the switch keeps sending wrong signals to the central computer; thus, the computer activates and deactivates the warning light as per the signals it receives.

You shouldn’t allow this to go on for a long time, because it could get to a point when your car won’t start up again; this usually applies to newer vehicles.

Note: for older vehicles that do not come with a dedicated oil pressure warning light/icon on their dashboard, a faulty oil pressure switch can intermittently activate and deactivate the check engine icon/light.

2. The Warning Light Never Goes Off

Apparently, no one likes it when too many warning lights illuminate on their dashboard, but they don’t just activate themselves; your car’s central computer must have received a bad signal, which led to the activation of those warning lights.

We talked of the oil pressure light coming on and off intermittently when the sensor is bad; now, if the warning light comes on, and even after refilling oil, the light refuses to go away, that’s another sign of a bad oil pressure sensor.

Normally, after the warning light appears and you top up the oil in your engine, it is supposed to go away – to only resurface when you’re running low on oil again. So, if it stays on even after an oil change, one of the things to troubleshoot first is the oil pressure sensor.

It is important to replace the sensor as soon as possible, so you can know exactly when you’re running low on oil.

If you let your engine run with low/no oil, it could get badly damaged, even worse, you may need a new engine because that damaged one might be irreparable.

3. Oil Leak From The Sensor Area

Leaks are not normal, regardless of where they’re dropping from. If you notice constant oil leaks from the sensor area, that is also a sign that you need to change the sensor. But, not everyone knows the location of the oil pressure sensor or switch.

The sensor sits in the engine’s oil system area where it can detect the oil pressure. This sensor comprises many treads, and when faulty, oil can leak through the treads or even from the sensor’s center hole.

It is alleged that Vauxhalls’ oil sensors – when they go bad – tend to leak through the center of the sensor’s body. The leak fills the block connector, and the sprays on other components in the engine bay. In this case, you’d notice oil leaks from different spots.

If you can, remove the oil pressure sensor block, and troubleshoot where the leak you’re experiencing is coming from. However, if this would be a technical task for you, engage an auto mechanic to help out.

4. Constant Noisy Timing Chain Yet No Warning Light

No one likes it when their car makes an unpleasing noise, and you should pay more attention if the noise is coming from your engine bay.

There are many components – chains, valves, moving parts – in the engine bay that requires constant lubrication to carry out their functions.

If these components stop getting enough oil, friction would increase, and you would start hearing loud cranking or ticking sounds as you drive.

Now, when you start hearing these unusual signs and your oil pressure warning light isn’t illuminated yet, it could be that you have a bad sensor.

A bad/damaged sensor would fail to detect when your engine is already running low on oil, and won’t inform the central computer; hence, the warning light won’t come on. In this scenario – when the sounds are consistent – you need to act quickly.

First, use the oil dipstick to check the current level of oil in your engine; also look closely to see if the oil is already dirty. If the oil is dirty, it needs to be changed, and if the dipstick reads that your engine is low on oil, you need to refill it immediately.

With this, it is apparent you had a bad oil pressure sensor because it should have detected the low oil and notify you by triggering the warning light to come on. So, as you go for an oil change (or refill), also endeavor to change the oil pressure switch/sensor.

Note: The noise may not only come from the timing chain; other metallic parts of your engine would make noise when they’re not getting enough lubrication.

5. Incoherent Oil Gauge Reading

While not all vehicles have an oil pressure gauge, if it’s available in your car, that’s another place to detect when you’re running low on oil. If the gauge goes down to “0” that means there’s no oil in your engine, and it’s dangerous to drive at that state.

But, it becomes a problem if the gauge stays at the “0” position – or stays steadily at a particular position – at all times (when you’re running low on oil and even after an oil change). In this case, it’s safe to assume you have a bad sensor.

The oil pressure gauge is built to get its reading from the sensor – through electronic signals. Hence, a bad sensor would be tantamount to erratic oil gauge readings.

Oil Pressure Sensor Replacement Cost

How much does it cost to replace oil pressure sensor?

Depending on the labor costs and the model of your car, the average cost of replacing oil pressure sensor is between $50 to $250.

On average, an oil pressure sensor costs between $30 to $100, while the labor can go between $20 to $150. Oil pressure sensor replacement cost for your car will also depend on the specified product number for the part; however, you can expect to spend between $5 to $100.

Fortunately, labor time will usually only be between 30 Minutes to 1 Hour, depending on the location of the sensor.

What More?

Overheating can also be a symptom of a bad oil pressure sensor. This is because one of the causes of engine overheating is low oil.

When the engine’s parts are not getting enough oil, friction would increase, and that can lead to overheating. When you start seeing any of these symptoms of a bad oil pressure sensor, act quickly.