Dodge Ram trucks are notorious for heater problems. A common repair is flushing out the cooling system and heater core. However, a coolant flush may not help and may even make the problem worse.
Symptoms
If the engine quickly reaches normal operating temperature but the heater blows cool air, the problem is usually a plugged heater core.
The heater core is like a mini radiator inside the heater's air housing. If hot engine coolant can't circulate through the heater core, the air blowing out of the vents will be cold.
How do you know if a heater core needs to be flushed?
- Your car heater blows cold air even when the temperature gauge reads normal, the engine starts and runs fine, and there are no other coolant system issues.
How do you know if a heater core needs to be replaced?
- Your engine runs hot during cold winter weather.
- Colored fluid is leaking from under the dashboard.
- There is an odd, pungent, sweet fragrance inside your car.
- Your windows fog up inside, especially when the heater's windshield defrost mode is selected.
Indicators of Plugged Heater Core
If your heater takes a long time to produce warm air and then rapidly cools off when the heater blower fan is switched on, your heater core is most likely plugged.
The heater core can become plugged with contaminants. The typical source of heater core contaminates is sediment resulting from not periodically replacing the coolant (lack of maintenance). Dodge Ram trucks can also suffer from casting sand not cleaned from the engine block during manufacturing, which can plug the hearer core.
This casting sand is stirred up by the coolant circulating in the engine and carried to the heater core. It settles into the heater core's narrow coolant passages and restricts the coolant flow.
Problem Caused By Coolant Flush
The main concern with flushing heater cores is disturbing sediment, which covers and seals holes created by internal corrosion. When the contaminants are disturbed and flushed out, the heater core starts to leak coolant inside the heater's air housing and leaks into the passenger compartment. Most people notice the coolant leak when it drips on their feet.
How To Decide If Your Heater Core Should Be Flushed
Replacing the heater core on a Dodge Ram truck is a costly repair. Flushing a plugged heater core can be a temporary repair that is often poor value. Deciding to replace the heater core is a difficult choice.
Dodge Ram heater cores are thin and corrode and perforate very quickly. Flushing a heater core can cause it to leak coolant. If the heater core is restricted by internal corrosion and sediment, flushing it out may uncover pin holes inside the coolant passages, causing it to leak.
If the vehicle has never had the coolant replaced, we strongly recommend replacing the heater core.
If the vehicle is under four years old and the coolant has been replaced every two years, the heater core may be restricted by casting sand and can usually be safely flushed out. However, there are no guarantees that the core will not leak after flushing, even if it is a relatively new vehicle!
An experienced Dodge Ram technician can usually quickly assess whether a heater core flush will solve the low heat output problem or if it will be an unnecessary step before replacing the heater core. This is definitely a situation where experience is important!
Cautions
- Flushing the cooling system on Dodge Ram trucks can stir up casting sand and sediment, causing a plugged heater core.
- Not regularly replacing Dodge Ram truck coolant can allow corrosion to form under sediment, creating pin holes and coolant leaks from the heater core.
Tips
- If your Dodge Ram engine or heater core shows signs of excess casting sand contamination, installing an accessory coolant filter can be a worthwhile investment.
- Flushing the cooling system on Dodge Ram trucks can also improve the engine's cooling and extend its life. This is especially true for Ram Cummins-powered trucks that transport heavy loads.
Recommended Dodge Ram Cooling System Repair Shop
State Street Auto Service
Whitmore Lake, Michigan
Near Ann Arbor, MI
Contact us. Now.