What Causes Oil Pressure Gauge Drops To Zero When Braking? (Explained)

We all know that it is important to make sure that you keep a close eye on your car’s oil pressure because you don’t want it to go too low or too high. In most cases, something below 20 PSI is already too low for your oil pressure.

However, when you brake, you might notice the oil pressure dropping all the way down to zero or close to that number.

Why is my oil pressure gauge dropping to zero whenever I brake?

In most cases, it is normal for the oil pressure to drop when you come to a full stop or when you are braking because the engine wouldn’t need too much oil when it isn’t moving. However, if it goes to zero or close to that, you might have low oil or your oil pickup tube has come off the pump.

The oil pressure gauge drops when braking.
The oil pressure gauge drops when braking.

The oil pressure is something that you should always keep an eye on whenever you are driving because this is one of the most important parts of making sure that your car’s engine is always healthy and well-maintained.

As such, you should be wary in case your oil pressure goes down to zero even if it might be something as simple as braking.


Related:

Is it normal that the oil pressure gauge drops to zero when I stop?

Whenever you are driving, one of the gauges you have to monitor from time to time is the oil pressure gauge because of how important the oil pressure is.

Basically, your engine needs enough oil to work properly, else it would overheat or get damaged through the normal course of its daily functions.

That’s because the engine’s different moving parts undergo a lot of movements that can cause friction. And by lubricating the different moving parts, they will be able to move properly without worrying about damage or excess heat.

So, that said, one of the most important things you need to do is to make sure that the oil pressure gauge does not drop to zero or somewhere close to that because that would mean that the engine isn’t getting enough oil.

As such, when it drops to a very low level that’s already close to zero while you are driving, that could mean that your engine is starved for oil and that your oil pump isn’t pumping enough oil into it for various reasons.

That said, when you are driving and accelerating, it is perfectly normal for your oil pressure to increase because the oil pump needs to work harder when the engine is spinning at higher RPMs. The higher the RPMs, the more oil the engine needs.

Read this excellent article on why the oil pressure gauge goes up when I accelerate: Why Does My Oil Pressure Gauge Go Up When I Accelerate? 

It also follows that, whenever you are driving at slower speeds or when your car is idle, your oil pressure is also pretty low but not too low.

Read this excellent article on the causes of low oil pressure at idle: What Causes Low Oil Pressure At Idle?

But what if you actually are breaking or coming to a full stop? Is it normal for your car to have an oil pressure that is close to zero or even at zero when you are braking?

So, in relation to that, what you should know is that your oil pressure should not be at zero or even remotely close to it whenever you are breaking.

That’s because, even when you are coming to a full stop when you brake, the engine is still working.

As such, the oil pressure should be somewhere in the normal range of 20 to 65 PSI but should probably be close to 20 or 30 PSI at full stop.

As such, when your car’s oil pressure is at zero or is dangerously close to zero, that means that it is far from being normal as there could be issues that could be causing this.

Your oil pressure should only be at zero when the car’s engine isn’t working because that’s the only time it doesn’t need lubrication.

Is 5 PSI oil pressure bad?

Now that we know that it can be a bad sign if your pressure gauge drops to zero when you are braking, what about if the oil pressure is at 5 PSI? It isn’t exactly at zero but does it still mean that you should be worried when the oil pressure is that low?

For starters, your oil pressure should at least be 20 PSI and not less than that. Anything that’s less than 20 PSI can be dangerous to your engine.

As such, even if your oil pressure is at 5 PSI and isn’t at zero, that could still mean that there are possible issues in relation to your oil pressure.

What causes the oil pressure gauge to drop to zero when braking?

When your oil pressure does indeed drop to zero when you are braking or coming to a full stop, what are the possible causes for this issue?

The first and most common reason why this is happening is that your car is low on oil. This basically means that you forgot to refill your car’s oil. You would probably notice this when your oil pressure gauge is usually at the lower end even if you are accelerating.

Meanwhile, the second reason why your oil pressure drops to zero when you are coming to a full stop is due to a problem with the oil pickup tube.

The oil pickup tube is responsible for carrying the oil from the reservoir to the oil pump so that the pump would be able to pump enough oil into the engine. So, if the oil pickup tube is damaged, your engine won’t be able to get enough oil even if you did actually fill your car with oil.

How to fix the oil pressure problem?

When trying to fix your oil pressure problem especially if it is usually dropping dangerously low and close to zero when you are braking, here are some of the possible fixes that you can easily use to remedy the situation.

Refill your oil fuel tank with enough oil until it reaches the “full” mark. There are times when something as simple as this is the right solution to your problem because the problem is also as simple as your car not having enough oil to pump into the engine.

However, the problem arises when you do have enough oil in your oil tank. So, when the issue is not in relation to not having enough oil, then it could mean that there is a problem with the oil delivery system in your car.

In most cases, the oil pump may be the problem but there are also times when the oil pickup tube is the problem as well.

So, if the oil delivery system is faulty or damaged, then the only way for you to remedy the situation is to have a mechanic diagnose the problem and then fix or replace any of the faulty components in the oil delivery system.

Sources

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