I bought my RX8 a couple months ago during the summer and everything with the HVAC was great. My AC blows cold but now that it's winter I realized that my car isn't blowing any heat. I tried soldering the HVAC connections but after some investigating I realized that the previous owner bypass the heater core.

What is the benefit for doing this? They did do an engine swap and the car was originally planned to be a track car but they ended up getting their GR86. Could I just get hoses and reconnect it to the heater core? Is it difficult to reconnect?

Bottom two inlets/outlet are plugged.

 

It was probably bypassed because it was leaking. Replacing the heater core involves disconnecting the AC and pulling the dash.

 

What would be the best way for me to check for leaks? Where does it leak into? The passenger footwell?

 

maybe, maybe not, possibly both sides, it just depends on how bad it is, if the drains are clogged, etc.

or you could try to set it up under light air pressure (15 - 20 psig max) and see if it holds

but most likely you should just replace it because that’s the only reason someone would do it on a street car, if you’re able to contact the previous owners they can maybe confirm it, or maybe they just “forgot” to mention it to you 🤔

they didn’t do it properly like that though, but moot point.
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I could contact them but I’m not sure it’ll they’ll remember haha. I’ll try that first.

What would a cheap way to get it under pressure? I don’t want to spend too much to test if I’ll need to get it replaced.

 

Or you can connect a hose directly on the heater and have another person inside the car to watch for leaks. But first be sure that the other side of the heater is open.