I have a D16 motor in my '88 CRX. Recently, the coolant temp gauge has been barely rising above "C", instead of running about 1/3 up from cold. I've seen this many times before, replacing the thermostat solves the problem. Not this time. A new Stant thermostat hasn't fixed the problem. Since the needle does move as the engine warms, I assume the temp sending unit is working. Suggestions welcome. With winter coming, I really want the engine to warm up quickly.

 

Try bleedding the coolant and if you have no leaks
its likely the sending unit under the distributor.
replace it with a Honda one from the dealer or junkyard. Aftermarket ones will not work

 

Thanks. It was cold enough yesterday for me to evaluate how quickly the motor was warming up. It seems to be warming normally (heater working within 5 minutes), so I suspect the temp sender is the culprit.

 

Why wont it work?
Honda doesn't actually make the part.

 

Temperature sending units from the aftermarket DO work. Just swap it out.