Engine overheating after 15 minutes of driving?

TOBYM

MEMBER
2002 DODGE RAM
4.7L
V8
4WD
AUTOMATIC
191,000 MILES

It blows water vapor out radiator overflow, I checked the thermostat and put it in hot water to ensure it works and it's in working order. Nothing appears wrong with the water pump, no coolant in oil. So, does that mean it's a bad radiator issue?

1 Reply

AL514

MECHANIC
4,677 POSTS

Hello, it sounds like you may have a bad head gasket. In the morning when the engine is cold, if your radiator has a cap, (some don't), take the cap off and start the engine, if there are bubbles coming out of the radiator opening it is most likely a bad head gasket. There are chemical tests you can get that will tell you if there are any combustion gases in the coolant. I'll post a picture of the kit you can get at a local auto parts store. To check the radiator for any potential clogging, you can use an Infrared Laser Thermometer to check the inlet and outlet of the radiator to see if coolant is flowing through it. You can get one of these also at an auto parts store, or Harbor Freight if you have them in your area.
The 1st picture is the Infrared Laser, and the 2nd is the chemical head gasket test, also known as a Block Test.

https://www.2carpros.com/articles/head-gasket-blown-test

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