idle overheating problem

[Th3 Lud3h23]

hey guys im gonna be as specific as i can be with every detail. so i have a 93 honda prelude with a h23a1 motor swap. im having an overheating problem. when i drive the car it does fine for as long as i wanna drive. but if i get in the car and start it up. i can sit there for like 3 or 4 min and it will overheat. smoke will come through the dash and out of my firewall getting all over the windsheid. heat doesn work either butt im workin on it. as the car idles and overheats there is a very sweat smell kinda like syrup or somethin. im not very sure what it is. i cant find any leaks anywhere. i do not think it is the thermostat but i got another one anyway. ive had thoughts of it being my heater core but i dont know for sure. so if you guys could help me or share your opinions with me that would be great. . .

[Trae%eh6]

the heater core sounds like it in a way. but what you smell is antifreeze. something eles to check for is maybe a blown head gasket. you can do this a few ways. 1 take your dip stick out and see if your oil looks milky. 2 take off your oil cap and check up inside the cap see if there is milky oil there. 3 you can check your reservoir tank. if you have a new thermostat i would go ahead and change it out

[Xeryon]

sounds like a heater core issue but the core might not be bad. it might just need a good flushing or maybe you have some air bubbles in the system that are preventing the coolant from flowing properly.

 

the problem with diagnosing cooling system issues in the winter is when it's cold enough outside the system barely has to do anything when you are moving. so your car may be badly overheating all the time but just having the air flowing through the grill is enough to keep it in check