Informational Guide

Why Is My Car Overheating?

Our guide covers everything from warning signs to prevention tips.

If you are heading down the street asking yourself, why is my car overheating - we might have the answers you seek. Any time your car is overheating, you are facing serious issues that must be addressed immediately.  

In this guide, we will answer "why is my car overheating and heater not working,” as well as “why is my car overheating when stopped?” 

Are you asking, “why is my car smoking under the hood and overheating?” First, you want to think about the symptoms that your vehicle is experiencing. If you notice these signs, it is likely that your vehicle is overheating, which can cause large problems if not addressed.  

  • Hood is hot to the touch 
  • The temperature gauge on the display is reading hot 
  • Engine warning light comes on 
  • Coolant begins leaking under the vehicle 
  • Burning smell from engine bay 
  • Steam comes out of the hood region 
  • Engine power is reduced 
  • Car goes into limp mode 

If you notice these signs, you want to figure out why the car is overheating and take steps to fix it.  

Warning Signs Of An Overheating Car

Why Is My Car Overheating? (Most Common Reasons) 

Leaks in the cooling system 

The top reason that a car overheats is due to leaks. The leak can occur anywhere in the cooling system, whether it is in the hoses, radiator, water pump, head gasket, or thermostat housing. You can typically see an external leak by looking under the vehicle.  

Coolant concentration 

If you’ve used the wrong type of coolant or you didn’t dilute it correctly with distilled water, the vehicle can overheat. Additionally, over time, the coolant becomes corrosive, leading to more wear in the system.  

Bad thermostat 

If the thermostat gets stuck closed, the coolant won’t be able to pass through, leading to an overheated engine. A properly working thermostat allows coolant to pass through when it’s needed the most.  

Bad radiator 

Clogs in the radiator, as well as leaks, can cause trouble cooling the engine. When the heat can’t be pulled away from the engine, it is going to overheat.  

Loose or broken belts 

When a belt is loose, or it breaks, the right coolant flow can't be maintained. This happens most often when the water pump belt breaks, turning into an overheating engine. 

Bad water pump 

The water pump is responsible for circulating water through the cooling system. The pump can suffer from leaks and erosion after many years of use, causing the engine to overheat.  

Identifying Common Situations For An Overheating Car 

  • During Winter/Cold Weather  
    Why is my car overheating in the winter, or why is my car overheating in cold weather? The engine gets hot no matter how cold it is out. With a defective cooling system, heat cannot be adequately dispersed.  
  • When You Stop   
    Why is my car overheating when at a stop or have you figured out why my car is overheating when I stop? When you stop the vehicle, there is no air rushing through to cool the system. Instead, the cooling fans need to take over. If these fans are broken, the engine will overheat.  
  • When Idling  
    Why is my car overheating in idle? As with the last issue, without properly working cooling fans, colder air isn’t being pushed into the system to cool the engine, leaving it to run at a higher temperature.  
  • When In Park   
    Why is my car overheating in park? Again, defective cooling fans are going to cause the engine to overheat. Your engine relies on the cooling fans whenever the vehicle isn’t moving.  
  • When The AC Is On 
    Why is my car overheating when the AC is on? It could be caused by a failing AC compressor that is putting a larger load on the cooling system or a clogged radiator that is preventing circulating coolant from reaching the engine.  
  • After A Radiator Replacement  
    Why is my car overheating after replacing the radiator, or why is my car overheating with a new radiator? It's possible that the radiator wasn't your problem. The issues might have also been caused by a bad radiator cap, a bad water pump, or a defective thermostat.   
  • With A New Thermostat  
    Why is my car overheating with a new thermostat? You may have replaced the thermostat for no reason. Instead, you should troubleshoot the other components of the cooling system, such as the water pump or radiator.  
  • With New Coolant  
    Why is my car overheating with coolant? If there are no leaks and the coolant is fresh, one of the cooling system parts has gone bad. We recommend checking the water pump and radiator for signs of trouble.  
  • While Driving  
    What causes a car to overheat while driving? Either a vital part is going bad, or there is a coolant leak somewhere that is putting a strain on the system.  

What To Do When Your Engine Overheats? (How To Fix It) 

It’s troublesome enough trying to figure out - why is my car smoking and overheating? In the process of getting to the heart of the issue, you want to take some important steps to mitigate any damage.

If you fail to take swift action, you could cause irreversible engine failure that could turn into a costly bill. To avoid facing these consequences, take these steps. 

  • Turn off the air conditioning 
  • Turn on the heating system to allow the heat to escape from the engine 
  • Pull over to a safe location on the side of the road 
  • Turn the engine off 
  • Check coolant levels and add more if needed 
  • Call roadside assistance and have the vehicle towed if you can’t get it to stop overheating 

If you take these steps at the first sign of an overheated engine, you might be able to repair the situation without any more damage. What might be a simple fix doesn’t need to turn into a costly engine replacement.  

Why Is My Car Overheating

What NOT To Do When Your Engine Overheats 

Here are some important things to avoid if you are asking yourself - why is my car overheating if it has coolant? 

  • Panic 
    By remaining calm, you can make smart decisions. 
  • Continue Driving 
    Is it safe to drive a car that overheats? What happens if you keep driving an overheated car? You should never drive in a car that is overheating, or you could ruin the engine.
  • Immediately Opening The Car Hood 
    The engine is hot, and you could burn yourself. Give it some time to cool down before popping open the hood. 
  • Letting The Issue Linger 
    By avoiding the issue, you only set the engine up for failure. 

Tips To Prevent Your Car From Overheating 

By preventing an overheated engine, you save yourself a lot of headaches and money. Here are some tips to protect your vehicle from dangerous and destructive heat. 

  • Park in the shade 
  • Tint the car windows 
  • Crack the windows slightly 
  • Turn on floor HVAC vents 
  • Use the fresh air setting on the HVAC system 
  • Watch the temperature gauge 
  • Turn on heat to cool down the engine
  • Top off the coolant 
  • Get the coolant flushed regularly  

Most importantly, if you notice any sign that the cooling system isn’t working as it should, you need to get it checked out by a professional.  

People Also Ask (FAQs)

Why is my car leaking antifreeze but not overheating? 

The defect is small and can be repaired now for a lot less effort than if you allow it to continue. It’s possible you only need to replace a radiator cap or another minor part.  

Why is my car smoking but not overheating? 

Chances are there is some sort of fluid on one of the hot components. It's possible you dripped some oil, transmission fluid, or coolant when you were topping it off.  

Why is my car running hot but not overheating? 

This is a precursor that the engine is going to start overheating if you don’t fix the problem now. Inspect the system or clogs or leaks and repair them right away.  

Why is my car overheating and my heat not working? 

Why is my car overheating and no heat? Chances are the two are related to one another, with a faulty blower motor or bad heater core. Plus, almost any fault in the cooling system can lead to these issues.  

Will an overheated car start? 

You might be able to start the engine, but you shouldn’t. An overheating engine will cause warping to the block or cylinder head, leading to permanent damage that’s costly to repair.  

How long can you drive on an overheated engine? 

You should pull over as soon as the engine starts to overheat, and follow the rules of the road. Continuing to drive under these conditions can lead to irreversible damage and require an engine replacement.  


Why is my car overheating in the cold? Your car engine can overheat any time that there is a problem with the cooling system. Pay attention to the symptoms and take action to prevent further damage.