Weird Coolant Issue

[Chris28]

Over the past few days, my temp gauge has been really low, like never going above half, and once I was moving again it would go all the way back down to as cold as it gets.

Tonight I'm doing some sprited driving, and as I come out of the last corner I see that steam is coming from under my hood, so I turn my car off right away. I open the hood, there is coolant everywhere, but all the hoses are intact and the rad cap is still on. I look under my car and there is a ridiculous amount of coolant under the car, and when I felt my hoses they were empty. I took off the rad cap and there was absolutely nothing in the radiator. The underside of the hood was soaked, and it kinda seems like all my coolant came out of the reservoir at a high pressure. What really baffles me is the lack of leaks. What I'm wondering is where all the coolant went, and is it somehow linked to my temp gauge telling me that my engine has been cold for the past few days? Tomorrow I'm going to check it all out and see what is up, but the whole thing seems really bizarre.

Anyone ever had this happen to them? Anything I should look for first?

[HoosierSX]

look all over your radiator.... it may have cracked in a place where you cant see right away

[whyteboi]

same thing happened to me once after i got home from work. it turned out to be a very thin slice in my upper rad hose, couldnt tell and wouldnt leak till it had the pressure

[OutToWinPAHC]

The bad is your may have overheated badly and don't know it. Since there was no coolant the temp sensor has not medium to read temp through. Fill her up and start checking for leaks, then once that's found and corrected your going to wanna check compression. And then monitor coolant.

[Chris28]

I have been checking coolant for the past few days because I thought the temp gauge staying cold was weird, so I made sure I had coolant in there. The amount of coolant underneath my car was practically the entire radiator's worth, so it let go all at once.

Edit: It's also a fairly new Mishimoto radiator, so I'll check for cracks but I don't think that's it.

[OutToWinPAHC]

Take it out of the car, cover up the bottom hose notch with plastic and tap and fill it out and look for leaks that way. Mishimoto has a good warranty so just call them up. I think Brian handles warranty at Mishimoto

[Chris28]

I found the problem, my heater core return hose popped off so that's where all the coolant went. It was too dark last night to see it but it was a simple fix. The car runs fine so I don't think I messed anything up, I mean the engine ran for probably 5 seconds without a full radiator of coolant, it still leaked a good bit after I turned the car off. Thanks for the replies.