Is it normal for a car chassis to rust?

[McRuth]

It is normal for a car chassis to rust. More related information is as follows: 1. The working environment of the car chassis is very harsh and it is often exposed to rainwater. Over time, rust is inevitable. The original car chassis usually has a layer of anti-rust coating, which can effectively prevent the car chassis from rusting. 2. During the use of the car, impacts or oxidation and peeling can cause the chassis to rust. If the car chassis is severely rusted, rust removal and anti-rust protection treatment are required. Car owners with the means can apply a car chassis armor in advance to effectively prevent the car chassis from rusting.

[LucasFitz]

Having driven for eight years, I've got some real insights about chassis rust. Back when I first bought the car, I used to panic at the slightest rust spot on the undercarriage and would rush to the dealership. The veteran mechanic there told me it's completely normal, especially on northern roads treated with de-icing salts in winter. Those cast iron components underneath are naturally prone to rust - as long as it's not major corrosion on the frame or suspension parts, there's nothing to worry about. During maintenance, I now pay special attention to the protective undercoating, promptly touching up areas where the anti-rust paint has worn off. Once during servicing, I discovered the exhaust pipe bracket had rusted through, so I replaced it with a stainless steel one for 200 yuan. That's why it's important to remember spraying the undercarriage during regular car washes.

[McMaverick]

Over the years in auto repair, I've seen plenty of cars with rusty undercarriages and can distinguish between normal rust and dangerous rust. A thin layer of rust on cast iron components is completely normal, just like a rusty iron wok. However, if you see yellow, mud-like rust bubbles at weld seams on the undercarriage, or if suspension springs are rusting to the point of flaking, it needs immediate attention. Extra caution is needed for cars from coastal cities—last time, a used car from a coastal area had brake fluid lines rusted through, which is terrifying to think about. For peace of mind, it's best to apply undercarriage coating when the car is new. For older cars, just use a flashlight to inspect the weld seams during annual maintenance.

[KendraFitz]

Last time I accompanied a friend to buy a used car, the seller swore it had no accidents, but when we lifted it, the undercarriage was rusted to bits. When buying a car, you really need to focus on the undercarriage. It's normal for cast iron parts to rust, but if the frame has rusted through with holes, walk away immediately. My own old car is eight years old, and I've replaced the rusted exhaust pipe three times, but the main load-bearing components are still in good shape. After the rainy season, it's best to use a high-pressure water gun to wash the undercarriage to remove mud and salt. Cars that are cleaned regularly will have at least 30% less rust than those that go five or six years without undercarriage cleaning.