Power Steering Noise

You love the luxurious feel of power steering, but lately it has started making a loud noise. So, what is the power steering noise and what does it mean?

There are three different power steering systems used in modern vehicles. The most common is a rack and pinion system that is given a boost by a hydraulic system. This system is comprised of a steering wheel connecting through a linkage to a pinion in the engine compartment. A pinion is long metal bar that turns along its axis when you turn the steering wheel. The end of the pinion sits on a rack that runs horizontally between the front wheels. When the pinion turns, the grooves in the end of it push the rack left or right per your input to the steering wheel. This in turn moves the tie-rods at each wheel causing the wheels to rotate left or right.

The power element of this system is hydraulically driven like your brakes. When you turn, the pinion rotates and the hydraulic system is activated. Most systems run off a belt that is connected to the engine and power steering pump. The pump powers up and pressurizes the hydraulic steering fluid. This fluid then activates a piston running along the rack that adds push to the rack. In truth, the piston does most of the work and you can spin the steering wheel with a finger.

So, where does power steering noise come from? Well, some vehicles are just loud. Larger ones like a bit SUV require a lot of power assistance and there is going to be some groaning from the piston. Smaller cars are a different matter. The biggest cause of power steering noise with them is a power steering pump belt that has started to fail. When this happens, it starts to slip and you can often feel the difference in the steering wheel. Replacing the belt is simple and inexpensive.

A secondary problem that can cause a bunch of noise is the failure of the power steering pump. It’s a mechanical device creating pressure. By definition, it is going to fail at some point given the slow degradation pressure can cause. The seals will eventually blow, but the hope is it won’t be for a few hundred thousand miles. When there is a problem, it will make an unholy racket and obnoxious noise.

The final problem could be something in your steering mechanism that is causing the power steering section to have problems. In general, these issues can involve the tie rods, rack or pinion. Some are cheap. Some are expensive. The only way to know is to take the car to a pro to figure out what is causing the power steering noise.

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