we just recently replaced the thermastat in my 95 honda accord, with a good 300k+ miles. everything was going fine till i drove it to school and when i got half way back the needle was over red. i stoped to check the motor and the hood of the car wasnt even hot, when i opened it antifreeze was everywhere, and the fan to cool the car wasnt on either. no idea whats going on, please any suggestions would be greatful

 

You may still have air pockets trapped in the system, and may need to bleed the air out.

Since you did not notice the radiator fan on when you were running hot, you should check it too. The radiator fan is the fan on the right side (passenger side), the AC compressor fan is the left one. The electrical plug to the radiator fan is at the bottom of the car and you usually have to jack up the car and remove a plastic cover at the bottom to access it. Then you connect battery power directly to the radiator fan plug to test if it spins. However, this is a lot of work.

An alternate quick test (although not 100% to isolate if the fan is working) is to unplug the connector to the thermo-switch on the thermostat housing, then use a wire or small paper clip and jump the connector. Then turn the key to 'on' to see if the fan comes on.

 

You probably unplugged the fan switch when replacing the thermostat. Check to see if it's still unplugged.

 

First, make sure the fan switch is plugged in like phootbag said.

Go back down to the autoparts store and ask them to check to make sure that the thermostat that you bought opens at the same time as the one you had in your car or you can take yours out and look at the bottom inside of the casing and look for the opening temperature and compare it to the one you took out. Secondly, make sure it's of the same exact design. I just had a problem where I bought one that had a higher operating temperature and the second one was too big, it wasn't designed for my housing.

 

Did you put it in the correct way.if you managed to put it in backwards it might not open.also bleeding the air out is an important thing poeple often overlook. and check your thermo swich as well

 

if none of those solutions work. when the car is warmed up. check if the lower hose is hot. if the top hose is hot and the lower hose is cold. then the rad could be clogged up. hopefully its a simple fix. like they said. recheck ur plugs and bleed it. GL