BMW steering wheel become hard to turn – possible causes and how to fix?

Sometimes we encounter some cases of steering wheels become sluggish and hard to turn, we will use a real repair case to describe this issue – possible causes and how to fix.

Vehicle information

Model: BMW 325i

Year: 2007

Engine: N52

Chassis: E90


Fault symptom

The steering wheel became very heavy while driving, very hard to turn, no warning light or message appears.


Possible causes

Checked steering system, this 2007 year 325i, N52 engine, hydraulic power steering system is purely mechanical, so it will not report a fault. The possible causes of this issue may be as follows:

Steering booster oil is leaked.

Oil passage blocked.

Booster pump does not work.

Steering gear malfunction.


Repair process

1. Check that the booster oil level is a little lower than the standard value, but it will not invalidate the booster.

2. Start the vehicle and check that the booster pump pulley is normal, but the booster oil does not have a clear flow when the steering is turned. Possible causes are the pipeline blocked or the booster pump not working, it must be removed and inspected. The released booster oil gives us the direction to check, as shown below:


3. Found a lot of iron fragments in the oil. Then took off the belt and turned the pulley of the power steering pump by hand, there was no sense of damping, and at the same time there was no sound inside the pump, then we can’t wait to remove the booster pump and disassemble it.

4. Open the back cover, and the fault point appears: middle shaft of booster pump is broken.


5. Replaced the booster pump, cleaned the oil passage and steering gear several times, then the test run was normal, steering wheel is not hard to turn.


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