If your car is overheating and producing smoke, you may get quite scared and think that you’re about to lose your car. But don’t panic! This happens all the time and more car owners than you can count have been through it. So, why does this happen?
Car overheating and smoking usually means you have a blown cylinder head gasket. The gasket forms a seal between the head and the block. If the gasket gets damaged due to overheating, it causes coolant to leak into the cylinders where it then turns into the smoke you see.
The following guide offers you suggestions as to why your car overheats and produced smoke under the hood at the same time. We’ve also discussed helpful tips on what to do if this happens and other frequently asked questions relating to this topic.
Why is your car overheating and smoking?
If your car is overheating and you notice smoke coming out through the exhaust, then you’re probably having a coolant leak. Smoke usually comes off your engine due to overheating.
If the smoke you see has some sweet smell to it, that’s further confirmation that the coolant is burning.
Smoke from your engine could also be caused by overheated fluids including brake fluid, transmission fluid, or engine oil. It could also be caused by heated residue on engine block or faulty wire casings.
To understand why your car is overheating and smoking, you need to study the type of smoke coming out of your car.
You should also note whether it comes out through the engine bay or the exhaust.
Here’s what different types of smoke mean in your car:
Overheating and white smoke under the hood
White smoke coming from your engine means you have a coolant leak. This can be caused by the following:
- Damaged radiator hoses: These hoses tend to swell and crack over time, and you can easily see the damage on your own by lifting the car hood.
- Cracked engine block: In extremely low-temperature conditions, the coolant can freeze and push against your engine block walls, resulting in small cracks. The cracks then cause the coolant to ooze through and fall into the hot parts of the engine where it burns and lets out white smoke.
Overheating and white smoke from the tailpipe
If your notice your car overheating and white smoke coming out of the tailpipe and staying long after you’ve started your car, it means you have a burning coolant that leaked into combustion chamber.
Here are a few possible reasons why this may happen:
White smoke indicates a blown head gasket
One of the most common causes of white smoke coming out of the tailpipe is a blown gasket head.
The work of this gasket head is to seal the internal combustion process and help keep the coolant and oil from mixing up.
If the gasket becomes damaged, usually due to an overheating engine, it allows coolant to easily flow into the combustion chamber where it burns, and evaporates in the form of white smoke.
To confirm if this is the issue, check your oil filter cap underside. If you see light-brown, creamy deposits on it, then the oil is mixed with water.
Damaged head cylinders
The cylinder heads are situated atop the engine block and are part of the combustion chamber. If they get warped through overheating, they’ll result in engine misfires.
Warping affects the airtight seal around these heads, allowing the coolant to easily slip through the openings and start burning as white smoke.
Since the head ought to perfectly fit with the connecting parts, replacing the head cylinders with new ones is the best option here.
Cracked engine block
if you have a cracked engine block, coolant can also easily leak through the cracks and onto the hot points of your engine bay where it burns with white smoke.
Keep in mind that an engine block is impossible to repair, so you’ll have to replace the entire block which can be costly.
Engine overheating and blue smoke:
If the type of smoke coming out of your car is blue or dark grey in color, then this is a sign that oil is burning in your engine. The oil has simply leaked/escaped and landed on various hot points of your engine where it then starts burning and producing blue smoke.
The oil leaks may have been caused by various issues including damaged pistons & piston rings, inlet manifold leaks, head gasket failure, worn engine oil seals, damaged PCV valve, and malfunctioning valve stem seals
What do you do if your car overheats and smokes?
If your car overheats and smokes, you should not drive your car any further. Find a safe spot to pull over and turn off your engine.
Give your car about 15-20 minutes to cool down before going under the hood for your own safety.
On opening the hood, if you’re struck by a smell of something burnt and slightly sweet, that means your car has a coolant leak.
The first thing you’d want to do is check the coolant level.
Next, inspect your car for the source of the leak. You can do this by performing a cooling system pressure test. This will help you easily pinpoint where the leak is coming from.
After the source of the leak is found, then the faulty part should be repaired or replaced to stop the leak.
Your mechanic may also perform a block test on the engine to find out if any damage has been done to your engine due to the overheating problem.
Overall, once your car starts overheating and smoking, we advise you to pull over and get towing services to tow your car to your favorite mechanic or auto shop.
The mechanic will then inspect the overheating and smoking issue in your car and repair/replace any failing parts in your engine system.
Why is your car overheating and smoking and leaking antifreeze?
If your car is overheating and this is accompanied by smoke under the hood and an external coolant/antifreeze leak, then you shouldn’t drive your car any further. Overheating and result in extensive engine damage or even cause a fire in your car!
The overheating condition is usually caused by low coolant level, a faulty radiator cap, a plugged radiator, damaged hoses, malfunctioning cooling fans, bad water pump or belt.
Some engine faults such as bad head gasket can also cause coolant leaks and overheating. Poor engine running condition is also to blame for overheating.
When faced with this issue, we advise you to get a professional mechanic to diagnose your car for the coolant leak and overheating issue and resolve them for you.
Why is my car overheating and steaming?
If your car is overheating and you see steam rising from the engine, it is most likely due to low coolant levels, a coolant leak, a dirty radiator, a bad water pump, a malfunctioning thermostat, or a damaged coolant hose.
When this scenario happens, open all the windows and turn on your car’s heater. This step is necessary to help expel heat from your engine. In the meantime, look for a safe place to pull over and turn off the engine.
Wait for the car to cool down (about 15-20 minutes) and then go ahead and check the coolant levels (a coolant leak is usually the cause of this problem). If the levels are low, top it off.
But make sure you get a mechanic to check your car for any of the above causes that could be causing overheating and steaming in your car.
Check out the video below on how to diagnose your car’s overheating and steaming issue
Why is smoke coming from engine but not overheating?
You may also notice smoke coming from the engine without your car overheating. This issue is usually caused by minor faults which can easily escalate into more serious problems if not taken care of on time.
The most common reasons for smoke coming from engine but not overheating include coolant leaks, oil leaks, oil spillage, oil filter caps, or damaged electrical wiring.
You can diagnose the exact cause of this issue by first locating where the smoke comes from. Is the smoke coming from your exhaust or is it your engine smoking?
You can then go ahead and use smell and smoke color to pinpoint which of the above culprits is behind the overheating.Car overheating and smoking can be a serious problem that requires immediate attention to prevent damage to your engine. At MotorAdvices, we understand the importance of keeping your vehicle running smoothly and safely. Our website features informative articles on car overheating, including what to do after installing a new radiator and after using BlueDevil to fix a head gasket leak. Our article on car overheating after installing a new radiator explains why this can happen and provides tips on how to prevent it. Similarly, our article on car overheating after using BlueDevil discusses the possible reasons for overheating and offers solutions to help you keep your engine running cool. Visit MotorAdvices to learn more about how to prevent overheating and keep your car running smoothly.
Your car overheating and blowing white smoke is usually a sign of a coolant leak and can be caused by a cracked engine block or damaged coolant hoses. Don’t drive your car further if it’s overheating and producing white smoke, or else you may end up damaging your engine.
Yes, an overheated engine may cause a fire in your vehicle. The engine may not blow and start a fire on its own, but it can trigger a chain of reactions that results in a fire. For instance, it may easily induce combustible components of your car such as oil to easily catch or spread the fire.
Absolutely! If your car runs low on coolant, it may cause the head gasket to blow. This results in smoking coming out of the tailpipe or the engine. Other symptoms of blow gasket include power loss, decreased engine efficiency, and engine producing knowing sounds.
Your car overheating and smoking at the same time is an indicator of a coolant leak due to faults in the coolant system. It could also be a sign that you have an oil leak which is burning and letting out smoke. Overheating is a serious issue that can cause catastrophic engine damage. So, we advise you to address the issue as soon as possible.
Follow the tips we’ve shared with you in this guide to inspect your car and uncover what’s causing the overheating problem. Or you can get a trained mechanic to diagnose your car and find the culprit causing this issue and hopefully fix the problematic parts.