Having a car is a great convenience, but it also means that you will have to take care of the vehicle and its maintenance. One issue that most drivers probably don’t want to deal with is a car that runs hot when at idle.
If you notice your temperature gauge rising at stoplights or just when stuck in traffic, it’s time you did something before some serious problems with the engine.
In this blog post, we will look at what causes the car runs hot while idle and the remedy for it.
Topic Summary
How Can You Tell If Your Car Is Overheating?
Here are the most important signs that your car is getting too hot and it shows on the dashboard display. The temperature gauge will climb higher than normal into the red zone, or an overheating light will blink.
Steam or smoke is coming from under the hood. The coolant inside the engine has reached a boiling point. The coolant or oil is leaking out of the engine. The engine produces poignant sounds due to the high load.
If you have noticed any of these signs, pull over safely and turn off the emergency stop. After you make sure your car is in a safe place, open the hood and let it cool down.
There is no need to add water to the radiator while hot. Driving a car with a very hot engine can lead to severe damage.
Causes of Car Runs Hot While Idle
If your car runs hot while idling but seems to cool once you begin moving, you know that the cooling system isn’t working correctly when the engine isn’t under load.
There are several things that might be occurring. They are given below.
Bad Cooling Fan
The cooling fan draws air through the radiator. It can help keep the engine in an optimum temperature range, meaning it may not overheat. However, if the fan is not working properly, the engine can overheat. This is especially true when the engine is not moving and is relying on only coolant and air passing through the radiator (i.e., when the car is not moving) to keep it cool.
Low Coolant Levels
Coolant fluid keeps the engine running at the optimum temperature. It can overheat if there isn’t enough of this fluid to transfer the engine’s heat away from its hot parts.
Stuck Thermostat
The thermostat controls the coolant’s flow through the engine. If it’s stuck closed, the coolant will bypass the radiator and not circulate, causing the engine to overheat. A stuck open thermostat is less common, but it will cause the engine to run cooler than necessary.
Clogged Radiator
Over time, radiators can become clogged with scale or debris, restricting coolant flow and preventing heat from dissipating.
Water Pump Failure
The water pump circulates the coolant that cools your engine. If it fails, the coolant won’t circulate, and the engine will overheat.
Air in the Cooling System
Air can form pockets in your cooling system, blocking coolant flow, especially if you just changed the coolant or had a leak that allowed air into the system.
Diagnose and Fix the Problem
Check the Coolant Level
This is an easy one. Check to see if there’s enough coolant in the radiator and the overflow tank. If it’s low, refill it to the proper mix. If the coolant invariably runs low, check for leaks.
Check the Cooling Fan
Monitor the fan as the engine warms up to operating temperature and see if it turns on and operates; if the fan doesn’t run, it could be a blown fuse, a bad relay, or a bad motor.
Hands on the Thermostat
A mechanic can test the thermostat to see if it’s opening and closing when it’s supposed to. A defective thermostat is an easy and inexpensive fix.
Flush the Radiator
If you think you have a clogged radiator, a radiator flush will help remove sludge and deposits. However, it should be done periodically as part of routine maintenance and upkeep.
Check the Water Pump
Look for coolant leaks around the pump, a whining noise when the engine is running, or evidence that coolant isn’t circulating properly, sometimes indicated by a hot lower radiator hose. Replacing a water pump is a little more work than changing other items, but it’s crucial to engine health.
Bleed The Cooling System
Air pockets can sometimes result in a frozen heater core, too, and bleeding the cooling system can remove them (removing them can involve different steps, depending on a vehicle’s make and year, so check your vehicle’s manual or let a pro do it).
Maintenance Tips for Car Runs Hot While Idle
To prevent your car from overheating while idle, consider the following maintenance tips:
Regular Coolant Checks: Keep an eye on coolant levels and top up as needed.
Routine Radiator Flushes: Perform a radiator flush as recommended by your car’s manufacturer.
Cooling System Inspections: Have your cooling system inspected periodically, especially before long trips.
Fan and Thermostat Checks: Ensure your cooling fan and thermostat are functioning properly.
FAQs On Car Runs Hot While Idle
Why does my car overheat only when idling and not while driving?
When the car is in motion, the airflow helps to cool the engine, but when it is stationary, the cooling is entirely down to the s. Even if the fan fails or the water levels drop down too low, you can find yourself boiling over.
Can I drive my car if it overheats while idling?
Unlimited idling will not improve the car’s performance and will worsen it if overheating occurs. An overheating car can be severely damaged. If the temperature gauge rises while the car is idling, it is important to turn off the engine and let it cool down before checking the coolant levels and the cooling system.
How do I check if my cooling fan is working properly?
To see if the fan is coming, you need to start the engine and raise the idle until the engine gets hot enough to come up to operating temperature, its coolant temperature. When it does, the fan will automatically go on to keep the engine coolant cool. Now, if the fan does not go on, one might go through the method of elimination to see if the fuse is out, the relay is faulty, or the fan motor itself went bad and needs to be replaced. A proper technician will make that assessment.
What kind of coolant should I use?
You also likely will find in your vehicle’s owner’s manual what type of coolant it recommends. Manufacturers generally specify changing the coolant every 30,000 to 60,000 miles, but this can vary based on the model of your car and how you drive your car. Obviously, preventive maintenance is paramount.
How does the water pump affect overheating?
When a water pump starts to fail, there are usually coolant leaks, a whining noise from the area of the pump, and the engine will start to overheat. The water pump is responsible for circulating coolant through the engine. If it fails, coolant will not flow properly, resulting in the car overheating, especially when idle.
Conclusion
Car is runs hot while idle. It’s a symptom that can’t be ignored. In fact, noticing the symptoms is a crucial first step towards getting your engine to run cool for years to come or taking it in to prevent further costly damage.
If you don’t know anything about the cooling system, talk with a mechanic before making the diagnosis yourself. Keeping your cool is an important part of automotive ownership.