i have a 94 del sol si with stock d16z6 that keeps sucking antifreeze out of the coolant reservoir and not returning it any ideas? it dosnt overheat at all and runs great but just not returning coolant to reservoir please help i have to drive from Colorado to mass

 

I have had the same problem on my 93 1.5L civic for about a year and a half now. car runs good and doesn't overheat i just never have any coolant in the overflow even a couple days after putting some in there. radiator for the most part holds coolant. i add maybe half quart about once a month but my reservoir leaks faster than that. don't know the problem but it hasn't really been an issue for me.

 

My 94 civic ex with a stock d16z6 does this too. Like both members mentioned above it runs fine except for stuttering a bit between around 1000 and 1500 rpms but it runs fine otherwise. Anyone know what's going on?

 

Need a rad cap.