Keeping your car running smoothly requires, at a minimum, regular oil changes and following the service recommended in your owner’s manual. But, if you do encounter problems, your senses can help you detect warning signs before you have an automotive crisis.

Here’s what you should know about the out-of-the-ordinary sights, sounds, and smells you might encounter with your car.

I smell coolant outside the car.
The syrupy smell of engine coolant means your car has a leak. Open the hood to try to find the source. It could be as simple as a loose hose clamp, split hose, or a failing radiator cap. All these potential causes have straightforward fixes — tightening the hoses or caps. Just don’t touch that radiator cap until the engine is cold. Yes, cold.

If those fixes don’t work, the cause could be a dying water pump, or a leaking manifold or head gasket; those are bigger jobs. In any case, if the leak is slow and the engine doesn’t overheat, you have time to drive to a nearby repair shop.

Finally, if coolant has leaked on to the ground, be sure to clean it up so animals don’t come in contact with it — the ethylene glycol in the solution is poisonous.

I smell coolant inside the car.
This situation sounds — and smells — like a leaky heater core. Tucked under the dashboard, this radiator-like component channels the engine’s heat to warm the car’s interior. Replacing it is an expensive, labor-intensive job. Get to a mechanic — but if the coolant is pouring out or overheating seems likely, call a tow truck.

I smell an acrid, burning-chemical odor.
It’s not burning oil, right? You know that scent. If the scent has a sharp odor, it may be that your brakes are overheating. Otherwise, it could be one of two easy fixes for any mechanic: a sticking caliper, or somebody (not you, of course) left the parking brake on.

I smell rotten eggs.
That sulfur smell signals an emissions problem. The dashboard “check engine” light probably is glowing, too. That’s serious and dangerous (as in: it could cause a fire). Get to a repair shop pronto.

I see water on the ground under the front of the car.
If it’s water — not brightly colored, sweet smelling engine coolant — don’t worry. It’s normal condensation from the car’s air conditioner. Water dripping from just behind the front fender is especially apt to occur during summer and after the car has been idling with the air conditioning running. On humid days, the amount of water can be considerable.

I see some water on the ground under the rear of the car.
Again, make sure the liquid is truly water. If so, it’s from the car’s tailpipe, and is simply an ordinary byproduct of combustion. This is most likely to occur when the weather is cool.

I hear a squeak when I apply the brakes.
These days, brake squeals shouldn’t be part of everyday driving. Hearing this noise is an indication that the pads are worn out or misaligned. Have your mechanic align the brakes or install new pads, both of which should quiet things down, and prevent further damage.

I hear ticking as the engine idles.
Have you checked your engine’s oil level lately? Ticking while idling is the sound of an engine not getting enough lubrication. If topping off the oil silences the noise, you’ve had a DIY victory. If the ticking continues, the issue could be low oil pressure. (A dashboard gauge or indicator light may also suggest this is the cause.) If so, get a professional on the case as soon as possible. The noise also could be the result of a sticking valve or leaking exhaust manifold, neither of which should be ignored.

I hear screeching under the hood.
If your neighbor’s cat isn’t missing, chances are you’re hearing a loose or worn belt. On cars more than a few years old, a serpentine belt can still appear to be in good condition, yet be worn out. Get it checked — and perhaps replaced — before a bad belt leaves you stranded.

If you’re hearing more of a metal-on-metal screech, this is a very serious situation that could indicate a problem with the water pump or the air-conditioning compressor. Again, get your car to a mechanic.

I hear squealing tires when I turn a corner. But I’m not speeding. Really, I’m not!
This is an indication of under-inflated tires, which are not only noisy, but also waste gas and wear out too soon. Get to an air pump and inflate them all to the recommended pressure (see your driver’s side door for appropriate levels). Then, check the pressure once a month to keep them at that level. Your car may have tire-pressure indicators, but typically these sensors don’t communicate with you until the pressure is well below optimum.