New subscriber here and maybe someone can help me out. I bought a 98 Accord Lx and i noticed that even after i warm up the car the temperature gauge stays down. I looked under the hood and saw that the engine coolant temp sensor was screwed in like normal but was not connected to the wiring. When i did connect it the temperature reading was at H. Even though car wasnt hot. I spent all my 2500 bucks buying the car and am low on cash for the month and cant be buying alot of parts to see what it is. Is it eather a bad thermostat or a bad ECT sensor?? Than to anyones answers

 

Does the temp gauge go to H when the engine is cold?
If it does, then there is a sensor or wiring problem.

Start here...
Overheating - Troubleshooting Honda's Cooling System

Verify the coolant is full and has been properly bled of air.
Engine off, preferably cold so as not to burn yourself, and open bleeder til a solid stream of coolant comes out.

 

Yes tried it. Engine cold and warm. Aswell as car off ignition on. If i plug the wire to the engine coolant sensor it shoots up to H. When i unplug it goes back down to C.

 

Id replace the sensor(You can test it prior to repalcing it if you want...I believe operating temp ~195Fish is around 175ohms, then ambient temp should be around 475-500ohns@70f. But if you do decide to repalce it, I wouldnt even drain the system...id just take off the distributor, unscrew the old sensor, then screw in the new one. Youll lose a lil coolant but not too much.

 

Tim73, weird thing is that the ect on my engine is on the side of the motor. It just unscrews off with a socket. Comparable to a camshaft position sensor. Is a spark plug looking piece that screws to the motor and then you simply plug in the wire to it. As far as i know that is the piece because i plug it in and the temp gauge goes to H. and i unplug and the temp goes back to C. Any thoughts??

 

Test the sensor. If it is pegged then it will need to be replaced.
IIRC the 98-02 cars had two sensors like the early 90-97 Accords, but during the mid generation refresh the sensors were reduced to just one. Early cars had two, one for the temp gauge, and one for the ECM.

Test the sensor.