I’ll admit it — for the first several years I owned a car, the only thing I knew how to do under the hood was refill the windshield washer fluid. Everything else felt like it belonged to a mechanic, not to me. That changed the day my engine overheated on a highway exit ramp in the middle of summer. It turned out my coolant was dangerously low and had been for weeks. If I had known how to check it — a process that takes about two minutes — I could have avoided a terrifying breakdown and a repair bill that exceeded four hundred dollars. Since then, I’ve learned the basics, and I want to share them with you in plain language, without any of the jargon that makes car maintenance feel intimidating.
Before You Start: A Few Basic Preparations
You don’t need any special tools for these checks, but a couple of things will make the process easier. First, check your oil when the engine has been off for at least ten to fifteen minutes. Checking oil on a hot, running engine is not only inaccurate — the oil is circulating through the engine block — it can also be dangerous. Hot oil can splash and cause burns. Park on a level surface, turn off the engine, and wait. Your owner’s manual is also your friend here. If you’ve never opened it, take a few minutes to find the section on fluid checks. It will tell you exactly where the dipstick and coolant reservoir are located on your specific vehicle, because these locations vary between makes and models.
You’ll also want a paper towel or an old rag. That’s genuinely all the equipment you need. No special training required.
Method 1: Checking Your Engine Oil with the Dipstick
This is the most basic and important check you can perform. Engine oil lubricates the moving parts inside your engine, reduces friction, helps dissipate heat, and prevents corrosion. Running an engine with low or dirty oil is one of the fastest ways to cause permanent, expensive damage.
Step 1: Open the hood. Pull the hood release lever inside the car — it’s usually on the driver’s side, below the dashboard. Then walk to the front of the car, find the secondary release latch under the hood’s edge (it’s usually in the center), and lift the hood. Most hoods have a prop rod — lift it and slot it into the designated hole to hold the hood open.
Step 2: Locate the dipstick. Look for a thin metal rod with a loop or T-shaped handle sticking out of the engine block. It’s usually brightly colored — yellow, orange, or red — to make it easy to identify. On most cars, it’s near the front of the engine. If you’re not sure which rod is the oil dipstick, check your owner’s manual. The transmission dipstick, if your car has one, is a different piece located elsewhere.
Step 3: Pull it out, wipe it, reinsert it. Pull the dipstick all the way out. You’ll notice the bottom portion has markings — two dots, two lines, or the words \”ADD\” and \”FULL.\” Wipe the dipstick clean with your paper towel, then push it all the way back in until it’s fully seated.
Step 4: Pull it out again and read the level. This second pull gives you the accurate reading. Look at where the oil film ends on the markings. If it’s between the two marks — or between \”ADD\” and \”FULL\” — you’re in good shape. If it’s at or below the lower mark, you need to add oil. If it’s above the upper mark, you have too much oil, which can also cause engine problems.
Step 5: Check the oil condition. While you have the dipstick out, take a look at the oil itself. Healthy oil is amber or dark brown and relatively translucent. If it looks thick, gritty, or jet black, it’s probably time for an oil change. If it has a milky, frothy appearance — like a chocolate milkshake — that can indicate coolant is leaking into the engine, which is a serious problem that needs immediate attention from a mechanic.
How often should you check? I check mine about once a month, or before any long road trip. Some newer cars have electronic oil level sensors that alert you on the dashboard, but I still recommend a manual check as a backup.
Method 2: Checking the Coolant Reservoir
Coolant — sometimes called antifreeze — is the fluid that circulates through your engine to keep it from overheating in summer and freezing in winter. Checking it is even easier than checking oil, because you don’t have to deal with a dipstick.
Step 1: Locate the coolant reservoir. With the hood open, look for a semi-transparent plastic tank, usually on the side of the engine bay. It will have markings on the side — often \”FULL\” and \”LOW\” or \”MIN\” and \”MAX.\” The cap may be labeled with a coolant symbol, which looks like a thermometer with wavy lines.
Step 2: Check the level visually. Because the tank is translucent, you can see the coolant level without opening anything. The fluid should be between the \”MIN\” and \”MAX\” marks. If it’s below the minimum line, you need to add coolant.
Important safety note: Never open the radiator cap or the coolant reservoir cap when the engine is hot. The cooling system is pressurized, and opening it while hot can release scalding fluid that can cause severe burns. Always check the reservoir when the engine is completely cool.
Step 3: Check the coolant condition. Look at the color of the coolant through the tank. Healthy coolant is usually green, orange, pink, or yellow, depending on the type. If it looks rusty, brown, or has particles floating in it, it may need to be flushed and replaced. If the level keeps dropping over time, you likely have a leak somewhere in the system.
I check my coolant about once a month, right after I check the oil. It takes about thirty seconds once you know where to look.
Method 3: Checking Oil on Cars Without a Dipstick
Some newer vehicles — particularly certain BMW, Mercedes, and Audi models — don’t have a traditional dipstick. Instead, they use an electronic oil level sensor that displays the reading on the dashboard or infotainment screen. If your car falls into this category, the process is different but still straightforward.
Step 1: Make sure the car is parked on a level surface and the engine is warm but has been turned off for a few minutes. The system needs the oil to have settled but not be completely cold, because temperature affects the reading.
Step 2: Turn on the ignition without starting the engine — usually by pressing the start/stop button once or turning the key to the first position. Navigate to the vehicle information or service menu on your dashboard display. Look for an option labeled \”Oil Level\” or \”Engine Oil.\”
Step 3: The system will display the oil level — sometimes as a bar graph, sometimes as a digital reading. Some systems also show the oil temperature, which is useful context. Follow the same logic as a dipstick: if the level is in the normal range, you’re fine. If it’s low, add the type of oil specified in your owner’s manual.
One thing to keep in mind with electronic systems: they can occasionally malfunction. If the reading seems off — like a sudden, dramatic drop when you haven’t noticed any leaks — it’s worth having a mechanic verify it manually.
What Oil and Coolant Should You Buy?
For oil, your owner’s manual will specify the correct viscosity — something like 5W-30 or 0W-20. Use exactly what the manual recommends. Thicker oil is not better, and mixing different types is not ideal. I buy a couple of quarts to keep in the trunk so I can top off between oil changes if the level drops.
For coolant, check the manual again. Some cars require specific types — don’t just grab any antifreeze off the shelf. Mixing incompatible coolant types can cause sludge and clog your cooling system. If you’re not sure, universal coolants are available that work with most systems, but the safest option is always what the manufacturer specifies.
Common Mistakes to Avoid
The most dangerous mistake is checking fluids on a hot engine. I can’t stress this enough — hot coolant under pressure can cause severe burns, and touching hot engine parts is painful at best. Always wait for the engine to cool.
Another mistake is overfilling. Adding too much oil can create foam in the engine, reducing its ability to lubricate properly. Adding too much coolant can cause overflow when the system heats up and pressurizes. Always add small amounts, check the level, and add more if needed.
Some people ignore warning lights on the dashboard — the oil can symbol or the temperature gauge — hoping the problem will go away. It won’t. If either of these lights comes on while you’re driving, pull over as soon as it’s safe and turn off the engine. Continuing to drive with low oil pressure or an overheating engine can destroy the engine in minutes.
How Often Should You Really Check?
I check my oil and coolant once a month as part of a routine — it takes less than five minutes total. I also check before any long drive, which is a habit that once saved me from driving across two states with dangerously low coolant. Beyond the monthly check, it’s a good idea to glance at the temperature gauge on your dashboard occasionally while driving. If it starts creeping above the normal range, that’s an early warning sign that something is off.
Final Thoughts
Checking your oil and coolant at home is one of the simplest forms of car maintenance, yet it can prevent some of the most expensive problems a vehicle can develop. You don’t need to be a mechanic, and you don’t need special tools. Five minutes a month is all it takes. If you’ve never checked your fluids before, open the hood this weekend, find the dipstick and the coolant reservoir, and take a look. It might feel awkward the first time, but by the third or fourth check it will be second nature. Your engine — and your wallet — will thank you.