No coolant in the oil or vice versa. HG's replaced ~45 days ago. Nothing is leaking at idle. A pressure test should find the leak, yes? 03 wrx mild mods. I believe original radiator.
Rate of coolant loss? Maybe the system wasn't burped completely and air is still being expelled into the expansion tank when the motor is hot and as the engine cools it is sucking in coolant to replace said air.
That would be not guess as well, maybe some air still there? Did you burp it when it was cold out and maybe the thermostat didn’t open before you called it good? Check it cold and hot levels in the expansion tank. Did you burp it from the turbo coolant tank? Worth a shot to try it again from the upper tank. I’m just thinking out loud.
Any sign of an external leak? Smell, drips on the ground, etc.? Is it pushing coolant into the expansion tank? Pressure test is a huge help with an external leak. But will not help with issues with the expansion tank, or internal leaks (if it won't hold pressure, but you can't see where it's leaking, don't just keep pressurizing it more than once or twice. It is possible to fill a cylinder and hydrolock the engine. If it seems weird, turn it over by hand, and then start it. If it billows white smoke, it's leaking into the cylinder). Ever since I bought a pressure tester, I've gotten in the habit of pressure testing anytime I have the cooling system open, I've found several clamps that weren't quite tight enough (which is why I've stopped using plain SS worm clamps, and look for spring or constant tension).
Pressure test revealed steady dripping of water under the intercooler at~15psi. I double and triple-checked all clamps most likely overtightening to be sure. What is the name of that hose? I'll be trying to locate one today. After installation, will I need to burp the system and how much coolant loss can I expect? This? https://parts.subaru.com/p/Subaru_2...rEngine-Coolant-Hose/49231084/21204AA351.html
If the leak is in a difficult to access location, I'm not adverse to smearing some Permatex No 2 on the connection so I don't have to disassemble things a second or third time trying to get the leak to stop. And ditto what Chux said about clamp styles.
Have Permatex 2 or it's generic on hand and will do that. Hose is not to be found at auto parts stores and will call Morries tomorrow or go online if I must as I need it asap.
Based on the pic I'd say that's not the correct part that's linked. I think it's this one here. I've never taken that one off without having the system drained at the radiator, so I don't know exactly how much will come out, but I'd imagine it'd be the entire contents of the upper overflow tank as well as possibly some of the radiator. That nipple on the back of the engine is pretty low relative to the other two things. If it were me I'd probably just drain the radiator and keep the mess where it's easier to catch in a bucket. You're already opening the system up to change that hose out, so might as well go big.
Cody beat me to it, upper heater core hose. Dealerships (at least a year ago when i last bought one) still had a bunch in stock.
