Radiator RX330

[CoryRX]

Hi, I’m Cory. Definitely used this site for info before through general internet searches. Just signed up to ask my own question. I will write an explanation now and add more detail once I’m sure I’m posting in the right place. I definitely am planning on a new rad not sure yet if I will attempt it or take it in. In the meantime I’m wondering a few things. I have pretty good skills but working on cars is definitely not my day job and my terminology may be sketchy.  So there is massive amounts of crystalized fluid all around the oustside perimeter of the rad all along the rad.  Fair amount of fluid on the bottom shroud. You know those bottom covers. Hoses and clamps all are ok. Because I’m in a bit of a bind right now I have gone ahead and used some stop leak. Went for some hard drives. The bottom hose gets hot but not enough to stop me from touching it. Upper hose is cool to the touch. In the few years I’ve owned this car it always amazes me as it takes so long for the temp to reach the halfway mark barely even in hot weather or long drives. Also the radiator cap never gets remotely hot to the touch. Is that normal? Do these cars just easily maintain that temp? Over the last few weeks I have added about a half a jug of rad fluid. The only real issue I have had other than the fluid I have found on the outside of the rad has been an occasional loss of heat inside the car mostly only when stopped at lights and once in park after work. It’s been extremely cold like near -40 lately warming up to normal for my area of -20. So to recap my main question is does the rad cap on these cars really just not get hot? I’ve spent a far amount of time looking for leaks and found none. I thought maybe there is something else happening causing the fluid to burp out through the reservoir release. So other than the fluid loss there seems to be nothing wrong. I’m worried if it warms up fast as it occasionally does here over heating would become a concern. Well I think I have mostly posted everything I know. Hopefully this is in the right place. Thank you for any help.

[RX400h]

Welcome, Cory.

If your thermostat is stuck open, your coolant temperature would take much longer to reach operating temperature, if ever.  Traditionally, thermostats were tested by the home mechanic by placing it into a pot of boiling water. It the thermostat stays closed, it is defective. However in your case, the thermostat would be open when you look at it (when the engine is cold), meaning that it never closed as it cooled down.