06 CRV. I am losing a good amount of coolant, and I'm not sure where from. I just pressure tested it and it held for a half hour. For some reason even when I let the car sit overnight and I open the cap it has some pressure and I can hear air hiss out. No milky oil. The other day I smelled coolant and saw that some had splattered over near the pulleys, and yet it will hold pressure fine with my radiator pressure tester. I'm kind of stumped and don't know what else to check.

 

Test for exhaust gasses in the cooling system with a rental block tester kit.

 

Run a compression and leak down test on the engine, and the exhaust gas tester that was mentioned above ^^ to 100% rule out a bad head gasket. If the comp test and leakdown test comeback good with no pressure escaping through radiator cap opening, then you're head gasket is good. Personally, I can think of two other possibilities. One, it only leaks when you have the heater core opened but once you put it on cold air it doesn't. Thus, it's leaking out your heater core. That's not as likely because you'd most likely notice coolant dripping inside your dash and onto the carpet. Two, it's an intake manifold gasket failure. I don't know about the CRVs, but B-series engines run a coolant line through the side of the intake manifold and it's possible for the gasket to fail at that spot and allow coolant to drip into cylinder 4's intake port. This wouldn't allow any coolant to be introduced into your oil/crankcase, but you would be burning coolant as it's being introduced into the combustion chamber the same way you burn oil if you have bad piston rings. I don't know how the CRV's intake manifold setup is but it's a thought.

 

I did a compression test and had healthy compression on all 4 cylinders. I actually do have a misfire on cyl 4 that I've been fighting with for a while. New plug, coil, and injector still didn't fix it so that's a good thought.Thanks