ej1coupedude

ok. so i have a 93 eg coupe. problem is its overheating. seems to do this every time it snows. haha. but anyway the lower radiator hose is cold while the upper hose is hot. heater blows cold. i checked the heater core by flushing water through the inlet nipple and came out the outlet nipple fine. pretty sure its thermostat but any other ideas so i can fix this and make it to work?? heres the breakdown

-hot upper rad. hose
-cold lower rad. hose
-heater blows cold
-heater core flows fine (pumped water through inlet nipple came out steady stream outlet nipple)
-radiator flows fine (attatched hose to top of radiator, removed bottom hose, steady stream.
-system seems to be getting a lot of air in the lines, however no leaks.
-doesnt lose coolant.

I bought another thermostat to try in the morning, but I dont want to have to call my buddy to drive 20 miles out of the way to come get me for work tomorrow. any ideas to check for are greatly appreciated.

(also new head gasket, and head resurfaced in last month or so, intake manifold gasket replaced at same time.)

migrod1

Sounds like ur coolant isn't flowing through the system, that's controlled by the thermostat, have u tried turning the heat on full blast?

vartok

sounds like the t-stat is stuck closed to me...

if that is the case, the the air in the lines would be from the coolant thats already in the motor boiling i would think

ej1coupedude

I have tried turning the heat on full blast hot and still blows icy cold. and i boiled the thermostat earlier to check if it was stuck closed and it opened around the time the water boiled. Im dreading the thought of a cracked block as I have about 85% water in the system. Have been so busy up until this morning when i first experienced the overheating that didnt get around to flushing and refilling. It has been high twenties to low thirties here temperature wise and supposed to go down to 18 degrees tonight. Im hoping it was the thermostat going bad and not opening until a hotter temperature than needed.

ke98248

iTrader: (1)

the water pump is working so it's not a "engine side" issue.

The radiator, lower coolant hose or the thermostat must be not working right/blocking coolant flow.

evo500

ej1coupedude

I ran water through the lower hose this morning as there was some ice blockage in the bottom lol and still did the same problems. ran water through the radiator and no restrictions. im thinking its thermostat but any ideas help. THANK YOU FOR ALL THE ASSISTANCE!!

stateofjustin

If you have flushed the entire cooling system and the water looks clean and clear, and flows readily through individual components in the system, and your heater doesn't work, there is only really two things that can cause an issue. The heater could just be a stuck heater valve, but as others have said, your thermostat is the most likely culprit.

After changing the thermostat, filling with 50/50 or whatever proportion is necessary to prevent freezing where you are at (if you have to mix be sure not to grab 50/50 pre-mix), bleed the cooling system. If you are not familiar with the procedure, post and I'll put it down. After the car is warm (both hoses), not only should your heater be working, but when the car reaches about 1/2 on the temp gauge, the cooling fan should cycle on (make sure the AC is off, or the fan will be on all the time).

Another point of failure can be the ECT switch (engine coolant temperature switch). Depending on the engine/year it is either in the thermostat housing, or underneath the distributor area on the head. Check it when the car is up to temp, it should not read open (should only read that cold, it's on or off only with a small range of temperatures between the two states). If it does, time for a new one. They are very common as they are shared with a TON of Honda and Acura vehicles. Between those two you should be aces as long as you don't have a blockage somewhere else in the system. That's why on questionable condition cooling systems, I recommend a pressure chemical flush from a flush machine.

Hope that info helps!