Losing small amount (1/2 cup) anti-freeze every month.
 

I'm adding small amount of 50/50 anti-freeze to my overflow container on 2009 civic dx every month. Probably not more than a cup every month or 6 weeks. First thing I thought was a cracked block because of the recent recalls but I don't see any puddles of coolant under my vehicle anywhere. I called Honda and my vin# is not listed in the recall bunch. So I purchased a block combustion tester and the test fluid stayed bluish green never went to yellow. I wrote the factory about the block tester kit but I probably sucked up some coolant when testing. I don't know where the coolant is going and really don't think it's too big of a problem but just curious where it is going. If anyone might have a clue I would appreciate it.Also I have that clunking noise when backing up into the driveway or turning into a parking space sharply. I replaced the outer tie rod ends because they had some play but clunk still there. Any help on this would be nice too. Thank you for reading my post and answering me. Have a good life!!!

Re: Losing small amount (1/2 cup) anti-freeze every month.
 

When using a block tester the test fluid should stay only blue. If green or yellow then there's exhaust emmissions getting into coolant via a head gasket breach. If you think you may have sucked in coolant during the test then repeat it after cleaning the tester.

The best test for head gasket breach is a cylinder leak-down test.

Inspect the radiator cap and replace if needed..use Honda Genuine only. May help to remove and clean the reservoir and the hose leading from the top of radiator to reservoir. Also, inspect all hoses while the engine is running.

Another place to look for leaks is the heater outlet valve ( near firewall). It can leak at the valve's adjustment arm's seal. Another area is the AC evaporator area.