What Causes the Steering Gear Noise in BMW 5 Series?
2 Answers
Reasons for steering gear noise: Loose connection between the steering wheel and the steering column. Loose connections between the universal joint and the steering column, and between the universal joint and the steering gear. Loose inner tie rod (inner ball joint) of the steering gear, and rusted outer ball joint. Methods and steps to solve steering gear noise: Determine whether the power steering pump is functioning properly. If the power steering pump is not working correctly, it cannot supply high-pressure oil. A simple test method is to securely connect the high-pressure oil pipe to the power steering pump with the specified torque, then unscrew the end of the high-pressure oil pipe connected to the power steering gear and leave it free in an oil container to prevent hydraulic oil from spilling and causing contamination. Start the engine and observe whether the high-pressure oil sprayed from the high-pressure oil pipe joint has a certain impact force. If the oil volume is sufficient and the impact force is strong, it indicates that the power steering pump is functioning properly. If the oil volume is insufficient or no hydraulic oil flows out, it suggests a quality issue with the power steering pump. After ruling out issues with the power steering pump and high-pressure oil pipe, proceed to inspect the suction oil pipe and return oil pipe. Most steering noise problems caused by pipes are due to the suction oil pipe, so the next step is to inspect the suction oil pipe. Since the suction oil pipe operates under low pressure, the above method is not suitable. In most cases, replacing the component is the way to troubleshoot. After replacing the suction oil pipe, reconnect all pipes and tighten the joints with the specified torque. Fill the steering system with oil, start the engine, put the transmission in neutral, press the accelerator while turning the steering wheel left and right, and continue turning the steering wheel after purging air from the pipes. If the noise and stiffness persist, it can be preliminarily determined that the suction oil pipe is not the issue. Next, inspect the return oil pipe, which also operates under low pressure, and can only be checked by replacing the component. After replacing the return oil pipe, repeat the above steps. If the noise and stiffness persist, it means that all hydraulic system components except the steering gear have been inspected, yet the problem remains unsolved. Through the preliminary inspection above, quality issues with the components have been ruled out. The cause may be a manufacturing error leading to mismatched power steering pump and steering gear. In this case, the steering gear or power steering pump may need to be replaced.
I once encountered a problem with steering gear noise, and I'd like to share my experience like chatting with a friend. There are several common reasons for steering gear noise in a BMW 5 Series: the bearing in the steering column might be loose, causing a rattling sound while driving, or the internal gears of the steering gear could be worn, leading to a clicking noise. Another possibility is insufficient lubricant in the power steering system, clogged oil passages, or low oil pressure, which can cause friction sounds. It's best to first check the power steering fluid reservoir to see if the level is adequate. If it's low, try adding the appropriate fluid. If the noise persists, don't ignore it to avoid compromising steering safety. Long-term neglect could make the steering heavier or even fail. I recommend taking it to a reliable repair shop for inspection—they can disassemble it to identify the specific issue. A friend of mine delayed addressing it and ended up needing a major steering gear overhaul, costing a lot of unnecessary money.
