The easiest way to check is to feel the heater hoses going into the firewall. Check the hoses from a cold start and check that both hoses get uncomfortably hot at about the same rate. This is a good indication that coolant is flowing.
could be head gasket problem. does your heater work? might need heater core , clogged up. do compression test. or bypass heater core and see if that works.
Give us the symptoms you are experiencing with your 2002 S-10? or Silverado? Such as, leaking coolant on passenger floor. lack of heat. sweet smell when heater is blowing.
Test Drive - 2002 Dodge Charger was released on: USA: 2005
Pressure test system to determine the origination of leak i.e. hose, radiator, heater core, etc.
Test Drive - 2002 Dodge Nitro was released on: USA: 29 October 2006
Your Heater Core Sounds Like. heater core Another answer== Water from condensation when using the AC, or coolant from the engine cooling system. Test to tell: if it smells like antifreeze, the heater core is leaking. No smell or just smells wet, it it condensate and a drain line is plugged or blocked causing the water to back up into the passenger compartment.
Open both front doors, remove everything, replace heater core, reinstall everything. Don't laugh, that is pretty much what you have to do. If you want to tackle the job yourself I would suggest purchasing a shop manual for that vehicle to help you through step by step.
get a coolant system pressure test, there may be a leak in the heater core.
Anti-freeze smell inside vehicle when you turn on the heat. Greasy windshield from the anti-freeze leaking from the heater core while the heat is running. Also check the passenger side of the vehicle carpet under the carpet and check the heater core hoses under the hood of your vehicle for anti-freeze leaking at the fire wall where the heater core hoses go. That about covers it. If all checks out do a pressure test on your anti-freeze circuit and this will definitely bust the culprit of the leak. Last of all, if you have no leak and your heat is not working and the heater core is in circuit with the anti-freeze with no leaks, replace the heater core. C.S
Check inside the engine near your windshield if the water drainage holes are open
Pull the top off of the black box on the passenger side of truck under the hood. Remove the two heater hoses. Remove the old heater core. Reverse the process. Top off the radiator with antifreeze and check again after a test drive. Enjoy the heat.
Your heater core has a leak, have the station pressure test your cooling system if it does not hold pressure you a leak in system