I've always been paranoid, for no real reason, of losing coolant. Anytime I'm under the hood I'll tap the reservoir and make sure the coolant is sloshing about above the MIN line. Today I hit it and no sloshing. I pulled it out and it was bone dry. I popped the rad cap and it was full to the top.

The car should not consume coolant, correct?

I plan on picking up some Honda coolant tomorrow on the way home from work. Then I'll schedule a pressure test of the system and maybe a compression test. My R does puff smoke (greyish color) when crossing over to vtec and sometimes well into it. I hope it's not a headgasket leak.

Is there any danger to driving for a day with an empty reservoir? I know I could add water, but just wondering what the dangers are. Anything I should be looking for besides the obvious leaks. The coolant in the rad didn't seem to have oil in it, but the hose in the reservoir was kind of funky with some dark scummy residue on it.

 

Coolant can be consumed at a very slow rate. Nothing like water however. Do a pressurized test and that will tell everything.

 

Change your oil and make sure there isn't any coolant in your oil system. Headgasket leaks don't take too long to create a larger problem. Is the scummy residue a rust color? If so, that wouldn't be out of the norm.