Toyota 4Runner Power Steering Pump Noise – What You Need To Do

Any strange noises when you start the car or are moving is also a warning sign of a serious problem in the car. Most of these noises you will only hear when your car is started and moving.

One of the common noises of the Toyota 4Runner that you can easily recognize is the noise of the power steering pump. It could be a rattling, hissing, or humming sound when you start the car.

When the power steering pump starts to have problems, it will make a small squeak or whine when you turn the steering wheel. You will start to find it difficult to control the steering wheel in curves.

That’s why we’ve put together a preliminary understanding of the Toyota 4Runner power steering pump noise to find out what causes it and how to fix it.

What Is A Power Steering Pump System?

The power steering system helps the driver control the vehicle, with less effort, easier and smarter in complex situations. Power steering uses the power of an engine and belt to power the pump.

It pushes power steering fluid through the system and allows the movement of a hydraulic piston in the steering box.

From there, the power steering system greatly reduces the effort required by the driver to turn the steering wheel.

The Toyota 4Runner’s power steering system uses the car’s computer and a small electric motor.

As you spin the wheel in bends, the computer sends a signal to the electric motor to move the rack and pinion. So you will feel the steering wheel control move more smoothly.

5 Reasons For Toyota 4Runner Power Steering Pump Noise

The power steering pump of the Toyota 4Runner will make noise due to different reasons. Here are the main causes and solutions when your power steering pump keeps rattling when starting the car.

1. The Power Steering Pump Corroded

One of the top causes of your power steering pump making noise is the quality of the machinery and the oil in the system.

The noise from the power steering pump is caused by the pump bearings failing and hitting each other creating a rattling sound when you steer.

If the power steering pump’s oil is almost empty, you should add more oil to lubricate the bearings in the system.

However, in case the oil is contaminated or has no viscosity, you should replace the entire oil in the power steering pump to protect the engine.

In particular, contaminated oil will cause spots on the pressure plates of the power steering pump. It will reduce the pressure on the steering wheel and make it heavy. The result is your power steering pump making a loud and jarring noise.

So if you hear any noise from the power steering pump, you should check the oil for possible contamination, damage, or any corroded parts causing them to collide and make noise.

2. Air Trapped In The Power Steering Pump

The noise from the power steering pump can be caused by air bubbles trapped in the oil.

If, after checking the oil and quality of the power steering pump, you do not see any damage, corrosion, or problems with the oil, you need to check for air bubbles in the oil. This can also be the cause of the power steering pump popping.

When you start the car, the air bubbles continue to move into the power steering pump and make some popping sound. If a large amount of air is trapped in the oil tank, your steering wheel will become heavier than usual.

You can check for this problem by removing the oil tank cap and checking for air bubbles appearing in the tank.

3. Oil Is Leaking From The Power Steering Pump

One of the reasons why the power steering pump makes a noise but few people pay attention to is oil leakage from the engine. The leak of oil from the power steering pump will make your car squeal continuously and make it difficult to turn around while moving.

Leaking oil will cause insufficient oil to lubricate the bearings and shafts causing them to collide and create a creaking sound when the car is moving.

When the oil is running low, your power steering pump will start making a loud noise. This is due to the pressure and friction acting on the steering wheel bearings.

Pressure and friction are among the main causes of damage to the bearing and other components of the power steering pump.

When you notice this problem, you should turn off the car and check for signs of this leak to fix it soon, avoiding the situation that the power steering pump system runs out of oil and affects the whole engine.

You also should check regularly to make sure the oil is not depleted and keep it to a minimum to avoid damaging the engine.

4. Duct Blockage

When the power steering pump’s duct is blocked, you will hear a whining noise when steering, especially you will have a hard time turning the wheel when the steering tube is blocked.

If the power steering pump hose is not clogged, it may be in the wiring, or the gear connected to the pump is damaged. This clog will prevent oil from circulating and lubricating the system, causing the engine to dry out.

If you cannot check this minor problem, take the car to a mechanic and fix the cause.

5. Power Steering Pump Faulty

If your power steering pump is damaged, it will emit a humming sound. Sometimes, you will rarely notice this noise because it is quite similar to the sound of a normal engine running.

However, if you pay closer attention to the pitch of the sound, you will notice that the humming is even and the sound is squeaky. As your power steering pump gets more severe, you will also notice oil leaking around the shaft.

If you discover a problem with the shaft, you should fix it immediately to avoid damage to the entire system.

Because, the axle is like a simple device in your car, but it contains the entire steering system, the bearings, and the electric motor. You should know that, as long as the pump fails, the steering system also fails.


If you hear any strange noises from the power steering pump, you should check it immediately to protect the entire engine in the system.

The first thing that you should do is turn off the car and diagnose the cause of this problem.

You can start by checking the oil in the power steering pump reservoir. If the oil is contaminated or depleted, you can replace or refill the oil tank. This you can completely do at home without the need for a repair engineer.

Don’t forget to check for air bubbles in the vehicle oil or oil clumps in the power steering pump hose.

If you can’t find the cause of the noise, don’t wait until the entire engine system fails, take your car to a repair center for assistance. Good luck!

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