8 Car Hacks That Mechanics Beg You Not to Try
I love doing my own car maintenance, but it’s not for everybody. Personally, I worked as a mechanic for more than 15 years. So, I’m comfortable with a lot of the work that needs to be done, and I also have the tools necessary to do the job. That said, everyone thinks that they have some brilliant “car hack” that will make it easy (and even safe) to DIY your own car maintenance. Unfortunately, many of these shortcuts will do more harm than good. So, before you try these eight car hacks, think twice. You’ll probably be better off giving your mechanic a call.
1. Using Coke to Clean Your Battery Terminals
Yes, Coca-Cola is acidic, but that doesn’t make it a safe cleaner for your car. Pouring soda on your battery can corrode nearby components over time. While it may clean visible corrosion, the sticky residue it leaves behind can attract dirt and grime. That gunk can interfere with electrical connections and eventually cause starting problems. Mechanics prefer a proper battery terminal cleaner, not a beverage.
2. Toothpaste as a Headlight Restorer
Toothpaste seems like a cheap fix for foggy headlights, and technically, it works—briefly. The mild abrasives in toothpaste may clear some haze, but they also strip away protective coatings. That leaves headlights vulnerable to UV damage, making them cloudier in the long run. Worse yet, the temporary shine can give drivers a false sense of safety. Professional-grade headlight kits are safer and more effective.
3. Taping Over Dashboard Warning Lights
If a dashboard light is on, taping over it doesn’t solve the issue—it hides it. Some drivers cover warning lights with black tape to avoid dealing with the problem, but this is a ticking time bomb. Those lights indicate issues like engine trouble, oil pressure problems, or failing brakes. Ignoring them can lead to catastrophic damage and dangerous driving conditions. Mechanics consider this one of the worst car hacks they’ve seen.
4. DIY Engine Flushes with Dish Soap
This one’s as bizarre as it is dangerous. Some online “gurus” recommend adding a little dish soap to your engine oil to clean it out. The logic? Dish soap cuts grease—so why not use it in your engine? The reality: dish soap wasn’t designed for internal combustion engines and will strip away vital lubrication. This can cause internal wear, overheat your engine, and ruin it completely.
5. Using Tire Shine on Interior Surfaces
Tire shine products are made for rubber, not dashboards, seats, or trim. Applying it inside the cabin may give everything a glossy look, but it also makes surfaces dangerously slippery. This is particularly unsafe if used on the steering wheel or pedals. Beyond that, some tire shine ingredients can degrade plastics over time. Stick to interior-specific cleaners to keep your car safe and looking good.
6. Plugging a Tire with Super Glue
YouTube might swear by this trick, but your tire—and your safety—deserve better. Using super glue to seal a puncture may work temporarily, but it’s never a permanent fix. The glue can’t withstand the pressure and heat generated inside a tire. A failed plug at high speeds can result in a blowout and serious accidents. Mechanics urge drivers to get proper tire patches or replacements instead.
7. Disconnecting the Battery to “Reset” the Check Engine Light
While disconnecting the battery may temporarily clear the check engine light, it doesn’t solve the actual problem. Modern vehicles have complex computer systems that log trouble codes for a reason. Removing battery power might erase those codes, but it won’t fix the underlying issue. Plus, you could lose other settings like radio presets, clock, and even anti-theft configurations. Always get the root cause diagnosed instead of resetting it blindly.
8. Fixing Windshield Cracks with Nail Polish
This hack might appear to slow down crack expansion, but it’s no replacement for professional repair. Clear nail polish hardens on the surface, not inside the glass layers where the real damage lies. Temperature changes, road vibrations, and moisture will continue to expand the crack. Over time, that small fissure becomes a spiderweb of broken glass. Glass specialists have the right resins and tools for a long-lasting fix.
Mechanics Just Want to Save You from Yourself
Everyone who wants to use car hacks to fix up their car likely has good intentions. They either want to DIY the work or save money (or both). More often than not, these quick fixes and “hacks” will cost you more money in the long run. Mechanics like me don’t hate it when people want to work on their own cars, but misinformation and rumored hacks can cause a lot of damage. Before you try any of these things, give your trusted mechanic a call. They’ll be honest about whether or not your fix is a good idea.
Have you ever tried a car hack that totally backfired? Share your cautionary tales or success stories in the comments—we’d love to hear them!
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Drew Blankenship is a former Porsche technician who writes and develops content full-time. He lives in North Carolina, where he enjoys spending time with his wife and two children. While Drew no longer gets his hands dirty modifying Porsches, he still loves motorsport and avidly watches Formula 1.