Why Do New Cars Have Rusty Screws?

[Drew]

New cars having rusty screws may indicate they are inventory vehicles that have been stored for an extended period, leading to screw rust. Solutions for rusty screws are as follows: 1. Tap the screw with a hammer or wrench. When a screw is rusted, avoid forcing it with a wrench as this will only tighten it further. Instead, use a wrench to grip the screw and strike the wrench handle with a hammer. A few firm strikes will loosen the rusted parts inside the screw, making it much easier to turn. 2. Apply cola to the rusted screw. Rust primarily consists of iron oxide, and cola contains carbonic acid, which reacts chemically with the rust, making it easy to remove and allowing the screw to turn freely. 3. If the screw is severely corroded, heating it with a flame is an option. Use an oxyacetylene torch to thoroughly heat the screw, then apply a drop of oil to the heated screw. The principle of thermal expansion and contraction will create more space between the screw and the nut. 4. Directly spray rust remover onto the rusted screw. Once the rust remover penetrates the screw, it can be easily unscrewed.

[Rochelle]

As a car owner who noticed rust on chassis bolts right after taking delivery, I did my homework and consulted experienced drivers. There are mainly a few scenarios for new car rust: First, issues during transportation/storage - vehicles shipped by sea may develop surface rust when exposed to salty, humid environments, even if parked outdoors for just days. Second, insufficient manufacturing details - like neglected anti-rust coatings on bolts around high-temperature areas such as brake discs. Third, use of ordinary carbon steel bolts instead of stainless steel parts in some non-critical areas. My dealership technician said minor surface rust isn't concerning unless it's on critical components like steering systems or engine mounts, but recommended prompt treatment. They taught me to remove surface rust using carburetor cleaner with a brass brush, then apply anti-rust wax. However, flaky red rust requires immediate workshop inspection.

[AliceAnn]

Through years of working with new cars, I've observed that rust issues primarily concentrate in three areas: First, the wheel hub mounting bolts, which are constantly exposed to brake dust and moisture; second, the decorative screws at chassis connection points, which have relatively weak protective coatings; and third, the non-core component screws in the engine compartment. These locations are exposed to high-temperature and high-humidity environments, becoming particularly noticeable during rainy seasons. While it's frustrating to see rust spots right after getting a new car, such surface rust generally doesn't affect safety performance - like how my own car developed rust during last year's typhoon season. My personal solution is to buy a can of WD-40 rust remover and scrub with a toothbrush. Importantly, never use sandpaper as it damages the protective layer. For severely rusted screws, it's more reliable to spend about a hundred yuan to have them replaced at a repair shop.

[MiguelDella]

A few days ago, I helped my neighbor inspect the chassis of his new car and noticed that many screws had developed yellowish rust. From a repair perspective, such issues are mostly due to supply chain problems. Nowadays, automakers use ordinary electroplated screws for non-load-bearing parts to cut costs. The humidity in shipping containers combined with poor port storage conditions easily leads to surface rust. The key is to assess the rust severity: if it can be scraped off with a fingernail, it's just surface oxidation and nothing to worry about; if pits remain after scraping, replacement is necessary. I advised him to pay special attention to screws on suspension arms and exhaust pipe hangers, as rust there accelerates aging. Prevention is actually simple: apply an undercoating spray before the rainy season and avoid using high-pressure water jets directly on screw seams during car washes. Nowadays, better repair shops have specialized rust removal pens that can fix the issue with a quick dab in about ten minutes.

[AbelLynn]

A friend just bought an SUV and found rust on the spare tire rack screws. As someone working in the automotive industry, let me share some insights. Automakers apply anti-rust treatments to critical screws during assembly, but non-structural components like interior panel fasteners are often overlooked. Transportation is the main culprit, especially rail freight where coal dust mixes with moisture to form corrosive layers. An interesting observation: new cars in humid southern cities show 40% higher rust rates than in northern regions. When addressing rust, it's crucial to differentiate locations—rusty door hinge screws may cause squeaks, while screws behind the dashboard are harmless. Recommended three-step treatment: first soak in white vinegar to remove surface rust, then apply anti-rust oil to lubricate threads, finally wrap with insulating tape for air isolation. During routine maintenance, remind technicians to inspect chassis screw conditions.