If your car is whining when turning, diagnose it with these tips from our expert mechanics. Find out how to check the power steering system for a fluid leak and what to look for if your car is making a whining noise when turning or leaking fluid.
Symptoms of a Problem with the Power Steering System
Whining Sound When Turning Your Car or Truck
Hearing a whining sound when turning your vehicle at fast and slow speeds could mean there’s a problem with a part in the power steering system, like the power steering pump or a swelled hose.
Harder to Turn the Steering Wheel
The lack of power assist steering can make it harder to turn the steering wheel. You might find yourself using more physical force to make a turn. Even if the assist seems to return and you find the steering wheel is sometimes hard and sometimes easy, it’s still a sign there’s a problem with the system.
Power Steering Fluid Leaking onto the Ground or Parts
An obvious sign of a leak is seeing fluid leaking on the ground beneath your vehicle, or finding it leaking onto other car parts.
What Causes My Car to Make a Whining Sound when Turning the Steering Wheel?
Low Power Steering Fluid
Low power steering fluid is the most common cause of a squealing or whining sound when turning the steering wheel. You can try to fix this by adding more power steering fluid to the system. Of course, it’s important to understand why the power steering is low and to check other parts to confirm they aren’t the cause or that you have a leak.
Contaminated or the Incorrect Power Steering Fluid
Contaminated power steering fluid can swell areas like the rubber bellow boot attached to the steering rack and cause leaking. It can also wear down parts like the internals of the power steering pump, cause poor circulation, and symptoms like a whining noise when turning. It can also cause a restriction in the flow of fluid.
Contaminated fluid may have debris. It may be discolored or darker than the color of your manufacturer’s recommended fluid. Check your owner’s manual for this information and the recommended intervals of when to change it.
Pro Tip: Different power steering fluids have different densities, so it’s important to use manufacturer-specified fluids.
Leaking Power Steering Reservoir or Hoses
Sometimes the power steering fluid reservoir can crack or break and leak fluid. The power steering hoses between the reservoir and the power steering pump can also break, crack, swell, or loosen over time, creating opportunities for leaks.
Broken Power Steering Pump
Power steering pumps can also break over time, and a bad power steering pump can make steering harder and cause your car to make a whining or squealing noise when turning. The pump circulates pressurized fluid through the power steering lines and down to the steering rack. The pump not only helps you turn the steering wheel with ease, but it especially helps when turning at lower speeds.
Electric Power Steering Pumps Won’t Cause Whining
Most modern vehicles will have an electric power steering pump. These power steering systems have electric power steering assist with a motor attached to the power steering rack. It also means the pump is not hydraulic. These kinds of pumps aren’t likely to cause a whining sound when turning. If your car has an electric pump and you hear a whining noise when turning left or right, chances are there’s another problem with your car, like an issue with the transmission fluid.
Air Is in the Power Steering System
If air is in your hydraulic power steering system, the fluid will aerate. Air in the pump can mix air bubbles in the power steering fluid, and cause the pump to malfunction. The pump will continue to wear and the whining sound will remain if the pump is left damaged. The pump’s failure to provide the optimal amount of hydraulic pressure can also cause weak power assist steering.
How to bleed the power steering system
How Can I Tell If I Have a Power Steering Fluid Leak?
Parts that can cause the power steering system to leak power steering fluid.
Steps to check for a power steering fluid leak or whining sound when turning your car
- Check the Power Steering Cooler
It’s common to have an external power steering cooler at the front of modern vehicles. It’s usually somewhere along the radiator behind the grille. These will be made of metal and exposed to outdoor elements. Areas that have snow or are humid can collect in this section of your car and rust or rot the cooler over time. This can cause the cooler to leak fluid.
- Check the Power Steering Lines
Generally, the power steering lines send fluid from the pump to the power steering rack, and other parts like the power steering cooler. These will be made of metal and rubber. Check for any fluid, wetness, or leaking on the lines and hoses.
For rubber lines, a coupler that holds the rubber to the metal may be leaking fluid.
- Check the Power Steering Rack
Power steering racks are usually mounted to a frame. It’ll have power steering lines leading to it. Check the area where the lines connect to the rack for leaks.
Also check down behind the bellows boot close to the inner tie rod ends. It should have a seal on each side. Check the seals for leaks. Make sure the boot is in good condition and not damaged or torn.
If the fluid is contaminated, that can swell these areas and cause leaks.
If there’s a low fluid level and you can’t find a leak, removing the bellows boot and seeing a lot of fluid pour out is a sign of a bad steering rack. Some drops of power steering fluid in this area might not cause issues, but more fluid than this, like the example shown in the featured video above at 5:10, means the steering rack needs a replacement. - Check the Power Steering Pump
Look along the shaft seal of the power steering pump for power steering fluid leaks. The seal can be difficult to see. It’ll have a pulley placed in front with a serpentine belt. If you’re able to see the seal, fluid leaking is a sign of a bad pump.
- Inspect the Reservoir for Leaks
Look around the location of the power steering reservoir for any fluid, wetness, or leaking on the hoses and reservoir to confirm there’s no extra fluid leaking.
- Check Underneath the Vehicle for Leaking
Look underneath the vehicle below where the power steering reservoir, hoses, and power steering pump are located for leaks. If the power steering reservoir was refilled, wait a few hours for any leaks, drips, or puddles. Look for a clear liquid, which is the color of power steering fluid. If there is dripping or leaking, it’ll need to be fixed.
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