Hello, new to the site here. I have a 2003 Odyssey that I bought about 6 months ago. I took it to a dealership to get checked out right after I bought it incase there were any problems.

I recently have been having a problem of the heat getting cool when idle or at a stop light. The radiator will loose coolant, but not sure from where. There are no visible leaks or smells that I can identify. The reservoir also gets drained anytime I fill it.

I have replaced the radiator cap after a suggestion from an auto parts store. Would the next logical step be the thermostat?

Thank you

 

When you say the heat gets cool.... Do you mean the needle on the temp gauge drops or the actual heat from the vents is getting cool?

Thermostats are cheap and fairly easy to replace. You're losing coolant from somewhere though, or there is a lot of air in the cooling system. Has the coolant been replaced lately? Or anything in the cooling system been touched?

If the temp gauge stays normal and just the heat gets cold, I would suspect a heater core next.