I am currently having an overheating issue.
car is a 91 dx with a lsvtec, turbo, 1/2 sized dual core PWR radiator, new thermostat.
when i remove the thermostat and drive it like that, the car will stay fine. soon as i replaced my thermostat, it acts like it doesnt want to open at all. the lower hose is cold, and when i squeeze it, coolant rises in the rad.

I had to move my rad in order for it to fit because of the turbo/dp is in the way. i do have an electric fan hooked up to it also. the car worked fine up until i put the turbo stuff on it, moved the rad over a little bit, and i had to have a 90 degree bend welded onto the lower rad hose bung because the rad hose was hitting on shift bar.

why would the thermostat not open up?

so in a nut shell:
car will not over heat w/ thermostat removed.

car will over heat with thermostat installed.

 

OEM thermostat?

 

Sounds like you have the thermostat installed incorrectly or the thermostat isn't working.
Boil some water and test is out.

 

 

thermostat was installed correctly. i did boil it, but should you have pressure on the front side of it for it to "pop" open? and no, it wasnt OEM, i will be picking up an OEM tomorrow to check it out.

 

No. Pressure doesn't pop it open.
It's in most every service manual and probably all over the internet for boiling the thermostat.
If it doesn't move in boiling water then it's bad.


Thermostats are pretty fragile. If you ever overheat -ever- then it's highly recommended that you replace the thermostat.

 

okay, then it was bad because it didnt pop at all, and i let the water hit 200 degrees. suppose ill be going back to autozone and handing them back their junk and getting my moneys back. guess this is what i get for going to then for parts ha

 

Just replaced it with oem honda thermostat. Still same thing happening. It flows just fine without a thermostat, but with one it wont flow and thermostat doesn't open

 

are you bleeding th system properly after replacing the thermostat. sounds like an air pocket is preventing it from opening.

 

you have to be putting it in wrong...

 

only other reason it wouldn't flow is air, and the only way those don't bleed is the little pintle in the tstat not being up.
Can't think of anything else atm.


edit: dammit people, stop beating me to the replies :p

 

Its installed right. Pin hole is at the top. As far as bleeding goes, idk how haha, time to search

 

B's don't have a bleeder, but you can try jacking the front of the car up to get more air out. It's a long shot though. And open the heater valve.

 

fill the radiator and leave the cap off. then run the car with the heater on until the cooling fan cycles. keep an eye on the coolant level and fill as needed.

 

Another long shot is head gaskets. I know it sounds crazy and its extremely rare. But I had an experience once where it didn't matter how many thermostats were thrown in, the thermostat never opened. If I bypassed the thermostat then it would flow but naturally you lose the heater. After a lot of researching, I called the dealer and they said in 8/10 cases the problem was the thermostat. But in 2/10 it was due to a faulty headgasket. So the head was removed and there was evidence of coolant seaping. At the bottom of the head there was coolant residue on 2 of the valve ends. So once the headgasket replaced, we placed the old thermostat and sure enough it worked. This was on a subaru though. I'm just sharing an experience.

 

x 2. Sometimes, it can take a while to purge all the air from the cooling system. Be patient and follow Dpetro's directions.