Why does the car make a rattling noise when starting?
4 Answers
This is caused by the engine oil temperature being too low and the ambient temperature being too low. When the engine oil temperature is too low, there is insufficient lubrication between the various components inside the engine. At this time, the friction between the components is relatively high, resulting in some abnormal noises. Engine oil primarily has three functions. Lubrication and friction reduction: It forms an oil film on the surfaces of two sliding components, preventing friction during operation and ensuring smooth movement of the components. Auxiliary cooling: When the engine is running, it generates high temperatures. When the oil reaches the operating parts, it absorbs heat and carries it away, aiding in the dissipation of heat from the components. Cleaning: It can carry carbon deposits, sludge, and worn metal particles from engine parts back to the oil tank through circulation. The flow of the lubricating oil washes away dirt generated on the working surfaces of the components.
Oh, my car also makes this rattling noise when starting, like something is loose. I remember once when driving an old Santana, it had an issue and the inspection revealed it was caused by worn suspension ball joints or a broken engine mount. It could also be clutch slippage making noise, especially when accelerating from a standstill. Sometimes, when the weather is too cold, rubber parts harden and make noise too. I suggest you don't ignore it—first, do a simple check of the chassis. Use a stick to gently tap around the wheels and listen for where it's loose. If the noise gets worse, go to a professional repair shop immediately, otherwise it might affect driving safety. Regular maintenance of the suspension system can prevent such failures—don't be like me back then, trying to save money only to end up stranded halfway. Driving should be smooth and safe—safety first!
As a car enthusiast, my small car has recently developed a similar rattling noise. At first glance, it might be due to a damaged universal joint in the drivetrain's half-shaft or a lack of oil in the differential causing the abnormal sound. The noise becomes more noticeable during acceleration when pressure increases, especially if the bearings are worn. I have a habit of checking the chassis every time I change the oil, and this time, I found a loose screw that just needed tightening. My advice is to start with the basics: check the tire pressure and suspension connection points. Don't delay, as the noise could worsen and damage the car, posing a danger. A friend's car once broke down due to a similar issue, and the repair only cost a few hundred dollars. In short, take good care of your car, and it will reward you with longevity!
A rattling noise is common during startup, which I analyze to be caused by loose suspension components or damaged engine mounts. Simply check the chassis for any looseness, and regular maintenance can reduce such issues. If the noise persists, seek repairs to prevent further damage. Safe driving is key.
