Once your car starts overheating, it might be too late. You might feel immediate panic set in as you see your temperature gauge climb and see the dashboard warning light. Is this one of those problems you can just ignore, and it’ll magically go away? Spoiler alert: it’s not.
The distance you can drive an overheating car depends on a lot of variables. You don’t want to roll the dice and keep driving if you can help it. Some cars might last a hundred miles in an ideal circumstance while others will stop running after just a few miles. Even if you successfully drive your overheating car home, your engine might be irreversibly damaged.
In this piece, I’ll talk about how far you can drive an overheating car. I’ll start by explaining why it’s overheating, what might happen, and what you should do once your car overheats.
Why Might a Car Overheat?
There are a number of reasons why a car might overheat. The general idea is that something within your cooling system isn’t working correctly.
A lack of oil or coolant is often the culprit when it comes to an overheating car. It could also be leaking components, a plugged heater core, or a radiator, or a water pump that is broken.
What Happens in an Overheating Car?
Your car has a built-in cooling system. This uses some chemistry and physics to cool down the hot parts of your car, namely the engine.
After all, the engine is creating a ton of heat whenever you’re operating your car. With all the motion and miniature explosions, heat is being generated.
The only way to get rid of all this unwanted heat is through a cooling system. Heat might be a great thing for a steam engine, but it’s a death sentence for a standard internal combustion engine.
So, when your car is overheating, different parts under the hood are getting hotter than they’re comfortable with. A lot of people might shrug off this heat. After all, cars are well-tuned machines, what’s so wrong with some extra heat?
It all depends on how overheated your vehicle is. Here are four general ranges that you should be mindful of.
What Happens if Your Car Is 0 to 20 Degrees Too Hot?
In this range, you won’t see any big changes. It’s still too hot for your engine, but (in most cases) you won’t experience any parts dramatically breaking.
What Happens if Your Car Is 20 to 40 Degrees Too Hot?
In this range, you’ll experience “engine knock”. This is when the air/fuel mixture in your cylinders burns unevenly.
It often feels and sounds like unexpected pops while driving along. Temperature drives this problem because it heats up the area above standard operating temperatures and can prematurely ignite the fuel mixture.
If you continue driving, you can shatter a piston ring, crack a piston, or melt the electrode snap on your spark plugs.
What Happens if Your Car Is 40 to 80 Degrees Too Hot?
When things heat up more, you have bigger problems to worry about. In this range, it will be blindingly obvious that something’s wrong. You should notice a huge drop in power and performance as you drive along.
More noticeably, you might hear a ton of rattling metal pieces banging around while you drive.
In this range, continuing to drive can damage the bearings, break the top piston rings, and destroy the interior surfaces of your engine.
What Happens if Your Car Is 80+ Degrees Too Hot?
Once your car overheats this much, you could be facing some huge issues. This temperature range is when “total meltdowns” occur.
The general answer is that your engine will never be the same again if you operate within this temperature for a long enough time.
In this range, continuing to drive can damage every component of your engine: crankshaft, rods, block, exhaust manifold, intake manifold, timing chain, valve spring, fuel system, and accessory drives.
The short answer is to avoid this temperature range as if your car’s life depends on it because it actually does.
How to Tell That Your Car is Overheating
Even though cars can’t speak English, they do a pretty good job of giving you a heads up. There are some common signs that say your car is overheating.
The Temperature Gauge is Climbing
Typically, the clearest indication that your car is overheating is a temperature gauge climbing towards the “H” area. Of course, this stands for “hot” and it means exactly what you think — your vehicle is getting hotter than it wants to be.
Your gauge won’t have temperatures displayed, just an arbitrary hot or cold scale. This means that you won’t know exactly what temperature your engine is. I wouldn’t suggest taking your chances if you see the gauge saying that your car is getting hotter.
A Loud Ringing Alarm is Going Off
In some vehicles, a built-in temperature alarm will go off. It sounds like a high-pitched alarm that just keeps buzzing until the car cools down.
A Dashboard Warning Symbol
There’s also a symbol on your dashboard that warns you of an overheating car. The symbol is supposed to be a temperature gauge in water, showing a high temperature. I always thought it was a key surfing a wave, but maybe that’s just me.
Regardless, when you see this symbol, it means that your car’s had enough. It reached dangerously high temperatures and it’s time to pull over. This is the same concept as a low oil warning symbol on your dashboard — it’s not a friendly reminder, it’s an urgent request.
You’ll Notice Steam from the Front
There are some times where gauges, warnings, and alarms aren’t working. In this case, you’ll have to rely on some physical evidence to understand whether or not your car is overheating.
One thing to look for is steam. Any time you see steam or smoke coming from the hood, it’s time to pull over and find out what’s happening.
Steam and smoke are the results of something getting way too hot and burning off. Unless you’re driving a steampunk car, this is a red flag.
New Smells and Odors Emerge
Besides smoke, keep a nose out for new smells. Again, smelling something new is typically a really bad thing, unless you just picked up your date for the night and she’s trying out a new perfume.
Coolant has a sweet smell and oil smells like something burning. These two liquids are the common culprits when it comes to a car overheating (more on this later).
What’s the Worst That Can Happen?
I outlined some of the problems that can happen in a previous section, but I just want to be clear about this: if you drive an overheating car too far, your engine will meltdown and become completely destroyed.
The engine is one of the most expensive components of your car. Once it breaks, you can almost guarantee your vehicle won’t be worth fixing.
What to Do When Your Car Is Overheating
Once you’ve established that your car is overheating, it’s time to cool it down. Since there are different reasons why your car is heating up in the first place, a little troubleshooting is built into this guide. Follow these steps before trying to make any major fixes.
Try a Quick Fix: Run the Heater
Before getting into the steps, there is a quick fix you can try. Turn on your car’s heater on the max setting and roll down your windows so you don’t overheat yourself.
By running the heater, you could actually reverse the overheating problem in your car. The idea is that hot air is getting sucked away from your engine. When you run your AC, your engine will actually heat up, so this is doing the opposite.
If your temperature gauge keeps climbing or your car doesn’t quickly cool down after this, then continue reading and follow these steps:
#1: Pull Over
First and foremost, you want to pull over. I can’t stress this idea enough — overheating isn’t one of those issues that can wait until you get home. Pulling over immediately will help prevent the massive engine damage I outlined earlier.
Make sure you’re safely out of the way of traffic. It helps to be on flat, solid ground, but it’s not a requirement. Again, the stress here is just to pull over, not to keep going until you see the perfect area to pull over.
#2: Wait 15 Minutes
Turn off the car and wait 15 minutes. Your engine bay is overheating, so everything around the engine is getting cooked right now. That could include your hood.
Trying to lift your hood and work in the engine area could result in you seriously burning yourself.
The coolant could be upwards of 220 degrees which is enough to do some damage.
#3: Check and Refill Your Levels
There are two liquid levels you really care about right now:
- Your oil level
- Your coolant level
So, it makes sense to check both of these. Be careful, though. This extra heat can also lead to pressure all around your engine. A coolant cap that would otherwise smoothly come loose can now be launched at you.
Here’s how you should check your levels: Use a towel and put it over the coolant cap, start slowly turning the cap while pushing down a little bit on it. When the cap is removed, take a look at the coolant level. It should be filled to the “MAX” or “FULL” line.
If it’s lower than that, put in a mixture of 1/2 antifreeze and 1/2 water until the coolant reservoir is full.
For oil, use the dipstick to see the level. Take out the dipstick, wipe it with a towel so the bottom is clean, then fully place the dipstick back into the hole. Remove it and you’ll see your oil level. If it’s low, time to top off your oil and find the leak once you get home or to a mechanic.
After refilling your coolant and/or oil, you’re free to start driving again. Keep a close eye on that temperature gauge and start working on your car as soon as possible.
#4: Call for Help if Levels Aren’t Low
But, what if your levels look fine but your car is still overheating? This means that something else is causing the excess heat in your engine.
On the side of the road, there’s not much you can do. It’s time to call roadside assistance or get a tow to your local shop. It might be best to go to a mechanic in this instance since they’ll quickly diagnose and repair the problem.
How Far Can You Drive an Overheating Car?
Now that you know more about what happens in an overheating car, it’s time to answer your question. How far can you drive an overheating car? Well, it all depends.
In general, you definitely don’t want to drive an overheating car that’s making engine noises. That’s one of the last symptoms you’ll encounter before something breaks for good.
I’d also highly suggest not rolling the dice in this case. The risk versus reward is just too skewed towards risk. You might milk a few miles out of the car, but you’re risking irreversible damage to your vehicle.
Cars don’t have an automatic shut-off that says they can drive exactly 10 miles after overheating then stop. Truthfully, the only thing that will stop your overheating car is when a part breaks. In other words, there aren’t safety systems built-in that will prevent you from driving an overheating car.
When I was a dumb kid, I drove my overheating car to the beach and back since I didn’t know any better (not like I had the knowledge or money to fix it, anyway). Still, that was just a minor overheat that I somewhat corrected by rolling down the windows and blasting the heater.
Maybe your overheating car will last as long as mine did, but maybe it won’t. There are a ton of variables at play, here.
It depends on the health of your engine, how overheated your car is, how lucky you are, and how you’re driving it.
One person’s car might conk out after a mile while someone else’s can go 100 miles.
As you just saw, there’s no real answer when it comes to how far you can drive an overheating car. It’s one of those things that you don’t want to ignore, though. Fix the issue as soon as possible to avoid totaling your car. For more car information and tutorials, explore my blog. Be sure to pick up the tools I highly recommend for car drivers.