Well, I
think it's the tester is sealing right... Hard to tell. I wasn't about to crank it any more than that. I used the #10 (red) cap, which doesn't seem to go quite as deep as the factory unit. None of the others fit, so that must be the one that was used.
Under 15-17 pounds of pressure, I'm hearing a hiss from the reservoir. If I cover up the overflow hose, it silences, but pressure still lowers observably. It doesn't drop like a rock, but you can sit there and watch it lower; maybe it would bottom out after a minute or so. The point is it's not going to hold it.
Bugger will sure hiss after three days parked, though; whether it's holding this pressure or not. I'm wondering if it's not sealing, or maybe there's a flaw in the reservoir neck.
Fluid level doesn't seem to be affected by the process, and it's still passing the combustion gas test. The only thing I noticed is the coolant seems to lower a lot in use, but I'm not positive it's entirely bled just yet, and I've done it since I observed that. Maybe later I can verify.
Maybe pressure is sneaking through that drain somehow; or around it. I do know that with the new hose and thermostat it's holding about ten degrees lower, but the way these thermostats are shipped and boxed, there's no telling what I have. It's only touched 190 once, and that's after stop and go traffic, and full throttle for a while into a sudden stop. It's hovering at about 184 to 188 now.
I think it's just a lower temperature thermostat. Whatever. A leak is still a leak. It may not be pushing boiling, but if there's a problem internally, it should still manifest. So far I haven't
seen any external leaks, but they can be sneaky.
I'm being as thorough as I can because the next step if it's internal is going to have to be an engine swap. Every gasket and seal from the oil pan to the front cover to the head gaskets and entire top end, along with all the hoses, oil pump, and water pump are new, and I'm not going to be able to swap the engine myself right now, so it'll be a
little more than a couple hundred bucks worth of parts I've allotted just to give it a final chance.
Cheers,
Kennith