Early 09 Honda civics (except Hybrid, SI Models) may exhibit coolant leaks at the engine block and be covered under Honda Warranty. As long as it has been less than 8 years you should be covered.
Steps to take:
1. Look for coolant leaking from the engine block cracks typically behind the engine oil/separator.
2. Pressure test the coolant system via the radiator and pinpoint to confirm.
Honda TSB 08-44 Information: