Why Is My Car Overheating?

Car Overheating

You notice the temp gauge creeps up to the red zone. All of a sudden the temp sign flashes on your dash cluster and you may even see some steam coming from the front of your car. In instances like these, the best thing to do is pullover! Every second you drive further may be damaging your engine more which can make your car repair bill all the more costly.

Car engines can overheat due to several reasons. The most commonly known reasons include a leaking radiator, broken water pump, faulty thermostat, bad coolant fan switch, or a coolant leak somewhere else in the cooling system. Coolant leaks need to be inspected thoroughly to eliminate any leaks or clogging occurring in the hoses, radiator, coolant reservoir, or engine.

If you’re on the road, once you pull over, you may notice steam coming from the engine bay and possibly even a puddle of coolant leaking from the bottom. It’s important to let the engine cool down. Once your vehicle already overheated, it takes much longer for it to cool down and if you try to drive it again, it can quickly overheat.

Tips on Minimizing Engine Damage

If for some reason you cannot stop or feel like you can make it to the closest mechanic shop, listed below are a few guidelines to help you minimize potential engine damage while driving.

Note: If your vehicle’s temp gauge doesn’t go down even slightly in a minute or two after applying these tips, pull over immediately to prevent any further issues.

  • Keep your revving to around 2,000-3,000 RPM – Even if you’re stuck in stand-still traffic, put the car in ‘Neutral’ or in ‘Park’ and rev it up to that range to keep maximum coolant circulation.
  • Turn OFF your A/C – This turns off your A/C compressor and any unnecessary components
  • Set your climate control to defrost mode on HOT and on MAX air blowing – Although this may seem counterintuitive, it’ll actually draw out the hot air and cool the car. The only tradeoff is that it may make the passengers a little uncomfortable.
  • By now you should start to see the ‘Temp Gauge’ move down again – If it’s still going up, pull over immediately.
Car temperature gauge overheating

Common Causes For Overheating

There can be multiple causes for an engine overheating. Sometimes it’s easy to visually inspect where the trouble area is but often times a careful inspection of the coolant system is necessary to isolate where the overheating is occurring.

  • Engine Coolant Leaks – If you’re pouring in engine coolant and you gradually see it disappear then you probably have a leak. Most of the engine coolant components should be inspected every 50,000-80,000 miles to ensure everything is working as it should. The radiator can start cracking, water-pump can have defective pressure, hoses can get brittle and crack. The radiator and hoses are easier to inspect but it can be much harder to do so with the water pump.
  • Bad Thermostat – The thermostat which has a key valve, can get stuck on a ‘closed position.’ This, in turn, restricts coolant flowing in your engine and ultimately raises the temperature levels significantly higher. Some car thermostats are simply poorly designed and will need to be replaced more often.
  • Coolant Mixture – I recommend doing a coolant flush every 30,000 miles or three years. Over time, coolant becomes more corrosive and does its job less efficiently. It’s important to also note that some automobiles require special coolant from the dealership. If you have a German car, chances are it needs ‘special coolant.’ Incorrect coolant-to-water mixture can also be an issue.
  • Radiator – The job of the radiator is to pull heat away from the engine and cool it down. If there is rust, corrosion, leaks or clogs, it may be time to get it replaced. It’s best to replace it at that point. Most times when a mechanic replaces your radiator, the old one gets recycled at a scrapyard.
  • Radiator Fan – Sometimes the electrical system of the engine coolant system is at fault. Relays, wiring, and fuses can go bad which can cause the coolant fans not to turn on. It’s rare for the fan motors themselves to burn out in my experience.
  • Engine Head Gasket – If you have a blown head gasket, you’ll notice that the coolant and oil have started to mix. You can check if it’s mixing by inspecting the coolant in the reservoir when the car is cooled. Coolant leaks out and the air gets sucked in. This is potentially one of the most expensive repairs due to the intense labor of taking apart the engine.
  • Water Pump – Lastly, another often neglected component of the engine coolant system is the water pump and its belt. If not routinely inspected in can cause more damage to the engine coolant system which can potentially cost you thousands of dollars more. Checking if the water pump pressure and belt are good is essential.
Topping of radiator engine coolant into the coolant reservoir

Overheating Repair Cost

The cheaper repairs are often associated with inspecting or replacing hoses, engine thermostats, the water pump belt, electrical, and doing the engine flush. Each of these services will range somewhere between $60-$400.

Next, the more expensive components to repair/replace are the water pump, heater core, radiator replacement. This can cost you between $150-$600.

Lastly, the most expensive repairs are ones that will break the bank and begin to make you consider if the car is still worth repairing. The repairs in this category include mostly engine work which is the head gasket and the engine block. These repairs can set you back $800-$6,000 respectively. Price largely varies on the year, make, model, and engine size.

Conclusion

It’s never fun when you’re driving down the road and out of nowhere an overheating issue occurs. Knowing what to do and what to look out for will help you save time and money. If you understand how the engine cooling system works, you can use that in your favor to minimize costly repair bills and get you back on the road again. If your car overheats and you’re feeling bad, just remember, it may not be as bad as you think.

Did you ever have an engine overheating problem? If so, how bad was it?

Also, read ‘How far can you drive on an overheated car?‘.

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Ernest Martynyuk

An automotive enthusiast who's been tinkering with vehicles since I was 15-years old. Repairing automotive electronics has been my main job for over a decade now and have a passion for everything technical regarding cars.

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