Bad news for any driver who’s seen their temperature gauge spike into the red, even briefly, and then fixed the apparent cause of the overheating. It’s easy to return to normal driving and assume you've dodged an expensive repair. But according to a viral mechanic on TikTok, that moment may have started a quiet countdown to a much bigger and far more costly engine failure. The recent clip from creator Chris Stone (@chrisfrombeachside) doesn’t try to sugarcoat or downplay what’s in store for owners of newer vehicles that have overheated at least once. Even brief episodes of extreme heat can warp plugs and plastic components, as well as major engine components that have lower tolerances than those in older cars. “When your car overheats, even briefly, you're not just stressing the cooling system; you're stressing every system attached to that heat,” he said in the clip that’s been viewed more than 15,000 times. “Plastic tanks and fittings soften, and head gaskets lose clamping force, and seals that were already aged get pushed past their limit. An overheat often cooks rubber seals, valve stem seals, O-rings, and coolant seals, making them hard and brittle.” Stone also explains that the damage from a single overheating event isn't always immediate or obvious. When temperatures spike, coolant can boil, creating air pockets in the system and reducing its ability to dissipate heat from critical components. Extreme heat also accelerates coolant breakdown and degrades the additives that help prevent corrosion and maintain heat transfer. That list of problems gives weight to Stone’s assessment that an overheat shouldn't be a fix-it-and-forget-it situation. Instead, it should serve as an alert to conduct a thorough inspection, including pressure-testing the cooling system, inspecting the radiator and reservoir for hairline cracks, and replacing plastic and rubber components that have probably been weakened and could be on the verge of total failure. Once the root cause of the overheating is fixed, he also advises flushing the overheated and almost certainly compromised coolant and refilling the system with the correct manufacturer-specified fluid to restore proper protection. Overheating Explained Commenters on the clip had difficulty determining what counts as overheating, especially since many modern cars no longer display precise temperature readings. One viewer wrote, “Anything past 220 is causing damage to your vehicle,” while another pushed back, saying, “Up to 230° is pretty normal for a 3.6L Pentastar. It is completely application specific.” One reason for the debate over the specific overheating threshold is that many drivers don't actually know what their car's cooling system is doing in real time. In older vehicles, a needle creeping upward was a clear warning. In many newer cars, the gauges are either heavily buffered or absent, replaced by a warning light that only activates when temperatures are already well outside the safe zone. It’s important to note that there’s no single standard operating temperature for every vehicle. Different engines are designed to have different running temperatures, depending on compression, cooling system design, emissions strategy, and whether the car has a turbocharger. Because of these differences, a temperature of 220°F might be dangerous for one car but perfectly fine for another. No matter the car, extreme heat can cause serious damage once it goes past safe limits. Problems like a cooling fan that won't turn on, a stuck thermostat, or a slow leak from an old hose can all make the engine run too hot. These issues get even worse if you're towing something heavy or driving in very hot weather. Know The Warning Signs When your car starts to overheat, it can be tough to know if you should keep going or stop driving altogether. If the temperature rises again soon after a repair, it's usually not safe to try driving all the way home. The better move is to accept the problem and prevent more damage. Turning off the car and calling a tow truck will almost always cost less than risking bigger repairs by continuing to drive. If you continue to drive with a compromised system, a small problem can quickly become a much bigger one. This can lead to damage beyond just hoses or sensors, so even if your car seems fine after overheating, it's important to watch for small warning signs. If the coolant level drops but you don't see evidence of a leak, or you notice a sweet smell from the engine, or white vapor from the exhaust when you start the car, these can all mean trouble. If the heater blows cool air when the engine is warm, it could also mean the coolant isn't moving as it should. Motor1 reached out to Stone via email and direct message. We’ll update this if they respond. We want your opinion! What would you like to see on Motor1.com? Take our 3 minute survey. - The Motor1.com Team