Why is my car overheating with no leaks

A carefree family hops in the car, excited for a weekend at the beach. After a few hours on the road, disaster strikes. The engine starts smoking, and the family has to pull over. What will happen next?!

Seems like no summer horror movie is complete without this iconic scene, but it’s certainly not something you want to reenact on your next road trip! Make sure you’re prepared if disaster strikes and learn what to do (and not do!) when your car engine overheats.

Why Do Engines Overheat?

Engines can overheat for many reasons. In general, it's because something's wrong within the cooling system and heat isn't able to escape the engine compartment. The source of the issue could include a cooling system leak, faulty radiator fan, broken water pump, or clogged coolant hose.

Regardless of the problem's source, an overheating engine isn't something you want to let linger. Your engine could sustain serious, if not permanent, damage.

Signs Your Engine is Overheating

If you’re able to take steps to cool your engine before it overheats to the point of failing, you may reduce the risk of irreversible engine damage. But first, you've got to notice the symptoms of overheating, which can include:

• Steam (which can look like smoke) coming from under the car hood.
• An engine temperature gauge on your dashboard that spikes to "H" or into the red. (Engine temperature gauge symbols vary, so consult your owner's manual.)
• A strange smell coming from the engine area. For example, leaking coolant can smell sweet while leaking oil might smell more burnt.

As soon as you notice the engine overheating, take the following steps and contact your nearest repair shop.

What to Do When Your Engine Overheats

1. Kill the A/C and crank the heat.

Immediately turn off the air conditioner to reduce stress on the engine. Then, turn the dial to maximum heat. This can help pull heat away from the engine to keep it from overheating until you can pull over in a safe location. You may get a little hot yourself, but a few minutes of discomfort is a small price to pay compared to major engine repairs.

2. Find a safe place to pull over.

Pull over and shut off the car. Allow the engine to cool for at least 15 minutes. Keep an eye on the temperature gauge, as it should move back to a normal range as the engine cools.

While you're waiting (and watching the gauge), put together a plan to get your overheated engine checked out. Call a friend, a tow truck, or your local Firestone Roadside Assistance for help. We'll dispatch a trained representative to tow your vehicle to the nearest Firestone Complete Auto Care store or help with step number three.

3. Check and add coolant (if you have it).

If your coolant level is low, a quick top-off could help protect your engine and prevent overheating until you can get things fixed. However, this step won't do much good if a coolant hose is clogged or the source of your troubles is a broken radiator fan or water pump. Consult your owner's manual to find the location of your coolant reservoir tank and to learn how to add coolant to your vehicle.

4. Restart the engine.

If your car isn't being towed, now's the time to carefully restart your engine and drive to your nearest auto repair shop. Keep an eye on the temperature gauge as you drive. If it rises again, pull over and let the system cool.

What NOT to Do When Your Engine Overheats

1. Don’t panic.

Your engine isn’t keeping its cool, but you can! Avoid swerving through traffic or slamming on your brakes when pulling off the road.

2. Don’t keep driving.

If your engine is overheating but still running, you're not doing it any favors by staying on the road. Sure, you may be able to get to your destination before it gives out entirely, but you may cause significant (and costly) damage by pushing your engine too far.

3. Don’t open the hood immediately.

Once you've pulled over, wait for the engine to cool before popping the hood to check things out. Opening the hood immediately can put you at risk of burns or injuries from spewing steam or smoke. Patience is key. Wait until the engine temperature gauge settles before opening the hood.

4. Don’t let the issue linger.

An overheating engine won't resolve on its own, even if it seems to be fixed after you add a little coolant. It will only get worse if left unaddressed. Get to the root of the issue to help save your engine. Bring your car to Firestone Complete Auto Care for a Complete Vehicle Inspection so we can diagnose the problem and make recommendations for solving it.

How to Prevent an Overheated Car Engine

Take care of your car, and it’ll take care of you. The best way to prevent an overheating car engine is to have regular coolant flushes and exchanges performed on your car, and stay up-to-date with radiator maintenance as recommended by your vehicle manufacturer. Routine inspections can also help you fix any potential radiator or engine issues before they worsen.

This summer, feel the heat at the beach, not on the road. Keep your cool and head to your nearest Firestone Complete Auto Care for the nationally-trusted auto repair advice and service you need.

Last Updated on September 29, 2022

While you should check your fluid levels every time you fill-up the gas tank, most people leave it to the mechanics. It’s a huge mistake. Just because you don’t see any fluids on the ground doesn’t mean that everything is working as it should. 

There are multiple places your coolant could be ending up, and if you aren’t keeping an eye out for the symptoms, you might end up with an engine that is constantly overheating. 

But where is that coolant going, and what can you do about it? Keep reading, and we’ll break it all down for you. 

Common Causes of Losing Coolant (But Don’t See a Leak)

Whether you drive a Subaru or a Lexus, your car needs antifreeze. So, when your coolant is disappearing, you need to track down the cause, and you need to do it quickly.

Below are the three most common reasons your coolant reservoir is empty time and time again.

See Also: How to Properly Check Coolant Level

#1 – Head Gasket

It’s likely the first thing a mechanic will tell you the problem is. Head gaskets are notorious for leaking, but it leaks everything right into the combustion chamber instead of the ground. While this won’t leave any visible signs on the ground, it will be pretty straightforward if you take a quick look at the exhaust.

If you have a blown head gasket, you’ll have a ton of white smoke coming from the exhaust. This is because unlike gas, which leaves mostly clear or black exhaust fumes, coolant burns white, no matter what color of coolant your car uses.

Expect your temperature gauge to rise way past normal also.

#2 – Radiator Cap

If you’ve ruled out an internal leak, that means your engine is burning the coolant somewhere else. The most common place is the radiator cap. Radiator caps hold the pressure inside the system, but if it’s not sealing properly, then some hyper pressurized coolant will escape in the form of steam.

Once your engine is warmed up, you’ll be able to tell if steam is escaping from your radiator cap by merely taking a quick look at it. You shouldn’t see any steam or smoke coming from the cap, and if you do, then you’ll need to replace it.

See Also: Can You Put Water in a Radiator in an Emergency? (It Depends on the Type)

#3 – Leak Onto the Engine Block

While a leak onto the engine block will typically leave a puddle under your vehicle at some point, if it’s leaking directly onto the top of your engine and puddling up until the engine warms up, it might burn the coolant off before it can reach the ground.

While it’s rare, it can happen, and just like a bad radiator cap, a tell-tale sign is a cloud of white smoke coming from the engine bay while the engine is running.

Step-By-Step Troubleshooting Guide

When it comes to disappearing coolant, finding the culprit is often the easy part. If you follow our step-by-step guide below, you should be able to identify the problem without ever needing to take it to a shop!

#1 – Check the Exhaust

It’s the most common reason that coolant burns off. It’s also one of the most straightforward problems to spot. All you need to do is look at the exhaust smoke while the engine is running. If there is excessive white smoke, then you have a blown head gasket.

However, just because there is some white smoke doesn’t mean that it’s a head gasket. It needs to be an excessive amount.

During colder weather, your vehicle will have more smoke coming out of the exhaust then during the warmer months. This is entirely normal.

#2 – Check the Oil

If you’ve looked at the exhaust smoke and still can’t tell if you have a blown head gasket or not, then take a look at the oil. Simply pull the dipstick and see if the oil level is rising over time.

When you get coolant in the combustion chamber, it doesn’t always get completely burned off. If it’s left in there, it’s only a matter of time before it works past the O-rings and finds its way into the oil pan.

If you’re an experienced mechanic, you can tell by merely smelling and feeling the oil, but novices often have to keep an eye on the level to see if it’s rising.  

If you do have coolant in your oil, you likely have a blown head gasket, and you need to have a mechanic take a look at your engine.

#3 – Check for Engine Smoke

If your engine is smoking, that’s a sign of a problem. Try and track down the smoke, but if it’s white, then it’s coolant.

If you don’t have a visible leak underneath your engine, then you should take a look at your radiator cap or anywhere along the top or sides of your engine. If you find any antifreeze, then you’ve located your problem!