When you turn the steering wheel on your Mercedes-Benz you may hear a loud squeaking or weird whining noise. The noise is a common problem, with Mercedes Benz E-Class, S-Class, C-Class and ML-Class and it is most noticeable when you first start up the car. Typically the engine is cold. Can often be heard when you are a stop light. Generally, the noise is worse when you turn the steering wheel and goes away once you drive off. The power steering makes an unmistakable noise that the experienced mechanics can distinguish in a matter of seconds.
The noise is very unique and no other component in your car will make similar noise to the power steering pump. Some may describe the noise as:
Any of the following situations can be caused by the power steering pump.
- Power Steering Noise When Turning
- Power Steering Whine
- Power Steering Pump Noise
- Power Steering Noise when Cold
- Power Steering Noise when turning left or right
- Power Steering Noise at Idle
There could be multiple reasons why you hear a power steering noise from your engine. Here is a list of the most common issues.
- Low Power Steering Fluid – Most common problem
- Power Steering Pump Defective
- Power Steering Fluid Leak
- Design of the pump
- Air trapped in the power steering system
- PS Bearings
How does the Power Steering sound when low in fluid?
Watch the video on this page to hear the noise that this power steering pump makes. PS reservoir has low power steering fluid level.
If your power steering fluid is low, getting rid of the annoying loud noise is as easy as adding more power steering fluid. To top up the power steering fluid you need 5 minutes.
Low power steering fluid could be caused by small seepage over the year or by a large power steering leak that need to be addressed if you have to add power steering fluid every month.
To add power steering fluid, remove the power steering cap and notice the dipstick on the bottom part of the cap. You could measure the ps fluid level with the engine cold or hot. There are high and low marks for both conditions.
Make sure to use the recommended power steering fluid for Mercedes-Benz. You can save on the cost of the power steering fluid by buying it online. See recommendations below or check your owners manual.
Recommended power steering fluid for Mercedes-Benz
Gulf ATF MX – Gulf Oil International, London/ENGLAND
Fuchs Titan PSF – Fuchs Petrolub AG, Mannheim/Deutschland
Liqui Moly LENKGETRIEBE- ÖL 3100 – Liqui Moly GmbH, Ulm/Deutschland
Megol Lenkgetriebeoel Stability – Meguin GmbH & Co. KG Mineraloelwerke, Saarlouis/Deutschland
MB 236.3 Lenkgetriebeöl – P/N A 000 989 88 03 Daimler AG, Stuttgart/Deutschland
Power Steering Stop Leak
If you have a power steering leak, we would recommend that you repair the leak instead of using a power steering stop leak. If the repair is too expensive or you are just trying to buy some time, you may want to consider a stop leak additive. Keep in mind that this is not a permanent solutioion and you will eventually need to fix the leak the right way. A highly rated power steering stop leak is the Lucas Power Steering Stop Leak Additive which also stop rack and pinion leaks.
The stop leak work by restroing dried, cracked, and shrunken rubber seals.