O'Fallon Auto Repair

Noticing a sweet smell in your car? It could be a coolant leak! Learn why antifreeze smells sweet, the dangers of ignoring it, and why O'Fallon’s Hillside Auto Repair is your best bet for a professional fix.   Why Is There a Sweet Smell Coming From My Car? If you’ve ever caught a whiff of a sweet, almost syrup-like smell inside your car, you might have brushed it off as something harmless. But in reality, that sugary scent could be a warning sign of a coolant leak—and ignoring it could lead to serious (and expensive) engine trouble. Why Does Coolant Smell Sweet? Engine coolant (or antifreeze) is typically a mixture of ethylene glycol, water, and corrosion inhibitors. Ethylene glycol has a distinctly sweet odor, which is why a leak often smells like maple syrup or candy. It's designed to regulate your engine’s temperature, keeping it from overheating in the summer and freezing in the winter.So when you&rsquo ... read more

The Shocking Truth About Electrical Gremlins Few things are more frustrating than replacing a blown fuse, only to have it pop again a day later. If your car’s fuses are blowing faster than a Missouri summer thunderstorm, you’re not alone—but you shouldn’t ignore it. At Hillside Auto Repair in O’Fallon, we’ve diagnosed countless electrical issues, and blown fuses are often the first sign of a deeper problem. In this post, we’ll cover: ✔ What fuses actually do (and why they blow) ✔ The 5 most common causes of recurring fuse failures ✔ Why DIY fixes often make things worse ✔ How we diagnose and repair electrical issues properly What Fuses Do (And Why They “Blow”) Fuses are your car’s electrical safety guards—they’re designed to break (or “blow”) when a circuit draws too much power, preventing wires from overheatin ... read more

When it comes to car maintenance, some components hog the spotlight—oil changes, brake pads, spark plugs—while others quietly do their job behind the scenes. One such unsung hero? The PCV (Positive Crankcase Ventilation) valve. This little gadget plays a crucial role in your engine’s health, and if it fails, it can cause some surprisingly expensive problems. What Does a PCV Valve Do? Your engine produces blow-by gases—a mix of unburned fuel, oil vapors, and exhaust—that can build up inside the crankcase. Too much pressure can lead to oil leaks, sludge buildup, and even engine damage. The PCV valve’s job is to redirect these harmful gases back into the combustion chamber to be burned off, reducing emissions and keeping your engine running smoothly. Why Is It So Important? A failing PCV valve can cause: Sludge buildup – Clogged oil passage ... read more

Your car’s battery is like the heart of its electrical system—it powers everything from your headlights to your infotainment system. But when something goes wrong, that heart can get drained fast, leaving you stranded in the O’Fallon Walmart parking lot with a dead battery and a bad mood. At Hillside Auto Repair, we’ve diagnosed more parasitic drains than we can count—and we know exactly how to track down the culprit before it leaves you calling for a jump start. How Your Car’s Electrical System Works (And Why It Drains Batteries) Your car’s electrical system is a complex network of wires, fuses, relays, and modules that all rely on your battery and alternator. Here’s the basic flow: 🔋 Battery – Provides power to start the car and runs electronics when the engine is off. ⚡ Alternator – Recharges the battery while driving and powers systems ... read more

If you're a car enthusiast in O'Fallon, Missouri, or just someone who loves a little extra power under the hood, you've probably heard the terms turbocharger and supercharger. Both are forced induction systems designed to boost engine performance, but they work in very different ways. At Hillside Auto Repair, we see plenty of vehicles with these systems, and we know how to keep them running at peak performance. What Is a Turbocharger? A turbocharger uses exhaust gases to spin a turbine, which then forces more air into the engine’s combustion chamber. More air means more fuel can be burned, resulting in increased horsepower. Key Components:Turbine & Compressor Wheels – Spins from exhaust gases to compress intake air. Intercooler – Cools compressed air for better efficiency. Wastegate – Controls boost pressure to prevent en ... read more