So while i was taking out my engine(b18a1), i changed my thermostat and now my temp gauge doesn't go up when i drive. The temp gauge goes to normal operating temp when i just let my car idle for about 10 min or so (normal) but when i start driving it goes back down to cold. My radiator fan does turn on and everything else seems normal. Just my idle is a little high because i guess the it thinks its still cold. Do you guys think its my thermostat? It's weird cause it was a brand new one though.

 

Did you install it with the bleed valve on top? Did you bleed the cooling system afterwards?

http://car-repairs.factoidz.com/how-...4-cyl-engines/

 

My guess is either, as mentioned, the thermostat was installed improperly or it is defective, [staying open].

Although if the rad fan is turning on it would indicate engine temp. is going over 190-200 degrees F.

Does rad fan turn on only if you're sitting idling or does it also turn on when driving?

Also as mentioned, make sure the system does not have air in it, bleed the system.

Your car has three (3) ECTS, the ECT switch, it controls the rad fan, [must be good if rad fan turns on] the ECT sending unit, it supplies the signal to the temp. gauge,[ sounds like it is working also] then there is the ECT sensor it supplies the ECU/ECM with what the engine temp.is, [if it is not working properly car will run rich when engine is warm] air in the system would mess up the signal.

Just because a part is new is no guarantee it is good and it is the first thing I would check, after making sure the system is free of air, bleed first, if that does not fix the problem pull the thermostate, make sure it was installed properly if it was pull it and test it, or if it is open, replace it. 94

 

Are you talking about the pin on the thermostat? and yes i did bleed the cooling system afterwards.

 

i am not sure if my fan turns on when i am driving but i think it only turns on at idle.

And one thing i didn't mention was when i started my car, i first had a CEL code 6 (ect sensor) and i checked the sensor and the red/white wire got disconnected from the pulg but i soldered it back. but im gonna get another one plug just incase that might be the problem. then i'll bleed it again. if that still doesn't work, i'll test my thermostat. thank you.

 

The ECT sensor would cause the engine to run rich, but it would have nothing to do with the engine temp. staying cold when driving, that sounds more like the thermostat is stuck open.

Engine temp. doing up to normal when car is not moving, [no airflow through rad] and then dropping to below normal when moving, [constant airflow through rad] is also a sign of a thermostat stuck open.

Air in the system normaly results in engine temp. moving up and down randomly and heat from vents would also be random.94

 

I have this same problem with my car right now. Im gonna check into it this weekend if i have time.

 

Right on. Thanks for the info. I bleed my coolant once more and it did help a little but it didn't solve my problem. im probably gonna take my thermostat out and test it tmrw.

 

nicknack25: Have you fixed ur problem yet? If so, what was the problem?


Thanx

 

I haven't had much time to take the thermostat out yet but when i re bled my coolant, it helped a little bit but it still takes like 30 min of driving or so to get to normal temp and still goes down sometimes while driving. i might have enough time over the weekend to get my thermostat out so i'll let you know how that goes.