have a 92 civic with a b16a in it with a p30 ecu. Car is currently not warming up past the 1st line when driving. If i let it idle in my driveway, which is on a slight slope for a few minutes the coolant temp gauge will move to about 1/3rd of the way warm. But when i go take it around the block it drops again to almost zero. Do you think i have a stuck open thermostat or any suggestions? thanks

 

yup. more than likely its stuck open

 

Most likely stuck tstat...

 

Well i just changed the thermostat, and that didn't solve the problem. In fact now the water temp gauge doesn't move AT ALL. And the lower radiator hose is not pressurized and cold, while the top is pressurized and warm. So my only guess now is that the lower radiator outlet is clogged. ANY Suggestions? imma take radiator off tomorrow.

 

take radiator out and flush water through it, it may be clogged

 

I don't see how a plugged up radiator wold make it run cold.

 

If the fluid's not circulating, the temp sensor may not be getting the warmed up fluid run across it. I'm not sure where the temp sensor is located in the path of fluid, but if the fluid around it isn't getting warm, it'll always read cold.

1- be sure you installed the thermostat properly, with the pin hole at the top. (I put one in upside down once and it didn't warm up properly)
2- while the engine is cold and hasn't been run, start the car and then take off the radiator cap to be sure the coolant is circulating and there are no air bubbles in the line.
3- if none of that works out, take the radiator out and try running the hose through it to make sure it's not plugged. Note: flush the radiator well while you have it empty

 

Try bleeding the cooling system.

 

yeah maybe bleed the system or check ur cooling fan coolant temperature sensor,coolant temperature sensor and your temperature gauge sending unit sensor all on the side of the head under the dizzy take them off clean them off or replace them hope this helps

 

So did you ever get it fixed?

 

Yes it was a frayed coolant temp sensor wire. So it was actually warming up the whole time. THanks

 

Cool.