2003 Honda Pilot - Okay... so the heater cores are clogged and I don't want to pay Mr Honda dealer any more money. Decided to attempt to unclog the heater core myself. Disconnected heater core hoses at the firewall and placed CLR in the core and let soak for 45 minutes. Flushed with water/compressed air and soaked in CLR for an additional 45 minutes. Then flushed with water/air, reconnected hoses. Used 3 bottles of prestone radiator cleaner and ran system for 4 hours. Noticed the proper heat output had returned.

Drained/flushed the system throughly and refilled with REGULAR GREEN COOLANT. Silicates and all that other "horrible" stuff. Until proven otherwise, put me in the "non-believing" camp in regards to this "type 2" coolant. I have several other older honda vehicles and have had ZERO problems with water pumps, radiator..etc with regular green coolant. However, I flush each car every two years.....

The heater core may eventually start leaking due to the corrosion issues in the cores. The CLR may have degraded the remaining life of the core, however, I have heat at the present.

Meanwhile... I am not happy with Honda's attitude regarding this whole episode. I believe they have coolant problems, or at the very least, coolant QUALITY CONTROL problems. They needed to make this right and failed.

 

Who told you the coolant needed flushing in the first place? I know it wasn't the owners manual. It specifically states the coolant doesn't need to be changed until 120k miles or 10 years. After which it should be changed ever 60k miles or 5 years.

Sorry you had troubles with the dealer. I feel your pain.

BTW: You can get the OEM radiator straight from Denso USA for $160. It's a PITA to change, but totally worth saving the $600+ over having the dealer do it. I just replaced my mother-in-laws radiator about 2 weeks ago. The hardest part was getting the lower hose and transmission cooler lines off the old core.