So my car overheated when I got to a car show on late Saturday. We had a police escort so it was a lot of stop and go. Which I understand could make that happen. But why would my radiator and reservoir be boiling with liquid?

 

Blown head gadget [WCS] .
Is your rad fan working?
Is your rad cap in good working order?
What is the MM&Y of car, trim level and any mods? 94

 

My radiator fan does work. Im assuming the radiator cap is good. I dont know how to really check to see if its actually good or not. If you could elaborate on that it would be great. And the model is a 93 civic si with a b18a1 motor swap w/ GSR head.

 

Basic check on a rad cap is does it hold pressure properly, but they are cheap enough to just replace.

The cap should prevent coolant flowing into the overflow bottle until engine starts to warm up, level in the bottle should always be between the hi and low marks.
When engine is cold fill rad with 50/50 coolant, [never just use water] properly bleed the system, [lots of vids out there on hoe to properly do that, once that has been done and engine has cooled down again insure rad is full and overflow bottle level is correct, [at low level line] start engine and bring it up to temp, till rad fan turns on at least twice, observe level of coolant in the overflow.

Having a thermos gun to check temperatures at thermostat housing upper and lower rad hoses when rad is not on and when it turns on can tell you a lot, you also want to know what the actual temperature is when you are "overheating", [match actual temperature with temp. gauge position].

You said it overheated, where on the temp. gauge did it go too??

Stop and go driving, especially in traffic, will run the engine temp. up, however if the system is working properly then there should be no problem. 94

 

It got to just above the icon on the temp itself and was steaming. When i opened my hood is could see steam and also here it boiling

 

As the engine warms up, check if the lower radiator hose is getting hot, if it stays cold when the car is fully warmed up or even as it starts to overheat you need a new Honda OEM thermostat straight from the dealer.

 

UPDATE
I tested my rad fan and it worked just fine. So that leads me to believe that it is my thermostat

 

Is it leaking any coolant?

 

Or you could just read my post and follow it.

 

Sounds to me like you may need a new thermostat