Why is the engine idle noise very loud?
3 Answers
If there is a buzzing sound inside the vehicle cabin during idle, it is highly likely to originate from the hydraulic power steering pump. If the noise can be heard while driving, it indicates that the power steering fluid is too dirty or there is an issue with the power steering pump. Below are the steps for replacing the engine oil: 1. Remove the old oil from the power steering fluid reservoir and clean it thoroughly, then reconnect only the oil supply hose after cleaning; 2. Extend the return hose of the power steering fluid reservoir and connect it to a container for collecting the old oil; 3. Place a funnel on the reservoir for easy refilling and prepare to add new power steering fluid; 4. Have someone inside the vehicle start the engine and immediately turn the steering wheel left and right; at the moment the engine starts, the person outside should begin adding new fluid to the reservoir. The disconnected return hose will continuously expel the old oil from the entire system and discharge new oil; 5. Reserve about half a liter of power steering fluid during refilling. When the return hose discharges new oil, stop adding fluid. Carefully observe the fluid level in the reservoir and instruct the person inside to turn off the engine when it drops to nearly empty; 6. At this point, since the power steering fluid in the reservoir is almost depleted, reconnect the return hose. After reconnecting, add sufficient power steering fluid to the reservoir. This completes the power steering fluid replacement process.
After running this auto repair shop for so many years, I've encountered numerous car owners complaining about excessively loud engine idle noises. The most common issue is unstable idle RPM, which could stem from ignition system problems—such as worn spark plugs or faulty ignition coils—causing abnormal engine vibration and noise. Alternatively, a loose timing chain can produce rattling sounds; neglecting this may lead to engine damage over time. Valve malfunctions are another culprit, where carbon buildup results in muffled noises. I strongly advise checking your engine oil immediately, as insufficient or overly thin oil increases friction noise, resembling a tractor's rumble. This isn't just annoying but poses safety risks, like stalling due to uncontrolled RPM. Don't delay—visit a professional shop for diagnostic scanner testing; it's worth the small cost. Preventatively, changing oil every 5,000 kilometers can slash failure rates by half.
Last week when I was driving my old car to work, I noticed the engine was making a drum-like thumping noise at idle, which startled me. I thought it might be because I forgot to check the engine oil regularly, and the low oil level caused increased friction noise, or maybe the belt was old and squeaking. After checking the user manual, I learned that such noises often come from high idle settings or computer glitches causing unstable RPM. I tried starting the car and listened for a few minutes in the parking space—the sound was coming from the front engine area, not the hissing sound of an exhaust leak. A quick check at a nearby shop revealed that the air filter was clogged, and cleaning it improved the situation significantly. I recommend not panicking and first checking the oil dipstick and belt tension yourself. If it's too complicated, it's better to have a mechanic adjust the ignition system. After all, ignoring it for too long can damage the engine, and trying to save money might end up costing more in repairs.
