Air Inside Cooling System, Help!

Air Inside Cooling System, Help!

7th Jul 2016

What happens if there is air in the cooling system aka an airlocked radiator? It damages your car's engine due to constant overheating.

Your vehicle’s cooling system flushes the engine with coolant to prevent overheating. When air gets trapped inside the cooling system, it prevents the system from doing what it’s supposed to do. Those vital coolant fluids won't be able to reach the critical components of your engine. This increases the risk of overheating, which is not good. To avoid costly auto repairs, it’s best to learn how to tell if air is in the cooling system and what to do about it. Consider this Air Inside Cooling System 101.

Causes of Trapped Air in Cooling System

There are several possible causes of this phenomenon. One is a faulty radiator cap. A secure radiator cap keeps your car's cooling system closed and pressurized. If the radiator cap fails, coolant can escape and let in air. This leads to trapped air in the cooling system. Here are some other causes of trapped air in the cooling system:

  • Blown head gasket
  • Leaking radiator hose
  • Leaking heater control valve
  • Improper coolant refill or flush

How to Tell If There’s Air in Your Cooling System

If there is air inside your cooling system, your vehicle will display certain signs. Here are some of the symptoms that show you have air in the cooling system:

  • Overheating during normal driving
  • Heater not functioning correctly
  • Reduced performance
  • Radiator leakage

Easy Fix for Air Inside Cooling Systems

If the problem is due to an improper coolant refill or flush, there’s an easy fix. Check to see if there is a bleeder valve on your car's cooling system. It’s a special valve that lets you bleed air from the system. This is the easiest fix for trapped air because you just turn a valve. If your car does not have a bleeder valve, there's this five-step method:

  1. Jack up your vehicle so the radiator is higher than the heater core.
  2. Carefully remove the radiator cap. (Note: Only do this when the engine is cool to avoid injury).
  3. Extract as much coolant from the radiator as possible using a baster or other suction device. (Note: Avoid spilling coolant onto the ground. It’s highly toxic, and just a couple of ounces is enough to harm animals or worse.)
  4. Turn the ignition and blast the heater as fast and hot as it will go while the radiator cap remains off. (This flushes coolant through the hoses, which should "burp" air from the cooling system.)
  5. After 15-20 minutes of idling, add coolant to the radiator until it's back to normal levels.

If the problem is due to something else, this is just a temporary fix. You'll need to identify what’s putting the air in the coolant system. If not, you’ll have to keep repeating this procedure. Meanwhile, you'll be exposing your car's engine to above-normal operating temperatures.

Tools to Fix Airlocked Radiators

It might be as simple as removing the coolant and refilling the radiator with new fluid. You can easily do that with a  coolant vacuum and refill kit. You can use this to easily refill coolant without producing airlocks. This is one of many vacuum coolant tools we carry. Shop JB Tools and get the best prices on the auto repair tools you need.