Temperature passing cool HAVE A 98 HONDA CIVIC THE TEMPERATURE KEEPS PASSING THE COOL MARK BEFORE FAN COME IN WHEN IT GOING UP IT TREMBLES SOME TIMES AND AGTER FAN COME IN IT DIP QUICKLY. I HAVE CHANGE FAN SWITCH, TEMPERATURE SWITCH, HEAD GASKET, ROD OUT RADIATOR How to solve a unstable temperature problems HAVE A 98 HONDA CIVIC THE TEMPERATURE KEEPS PASSING THE COOL MARK BEFORE FAN COME IN WHEN IT GOING UP IT TREMBLES SOME TIMES AND AGTER FAN COME IN IT DIP QUICKLY.I HAVE CHANGE FAN SWITCH, TEMPERATURE SWITCH, HEAD GASKET, ROD OUT RADIATOR

Over heating the engine is a serious concern. With the hood raised you should hear the motorized fan turn on just behind the radiator as the engine requires additional cooling.. If you look in from the rear of the radiator you should see the fan blades.

This electric powered motor operates on a thermostat and when the engine temperature rises this fan should come on. I'm assuming from your description that when driving and air is flowing through the radiator as the car travels the engine is nor overheating.

Check fan motor thermostat, check fan motor and check wiring.

Wiring Diagrams related to the Honda Civic
http://www.wiringdiagrams21.com/category/automotive/honda-automotive/civic

Motor engine cooling fan only runs as engine temperature requires additional cooling.

could have faulty engine coolant temperature sensor.

YOUR AIR CONDITIONER PUT LOAD ON ENGINE CHECK TO MAKE SURE RADIATOR COOLING FAN RUNNING BECAUSE IT HELPS TO KEEP THE ENGINE COOL AND AC CONDENSOR COOL FAN NEED TO BE RUNNING IF NOT CHECK COOLING FAN FUSE OR RELAY.

the system may be clogged up somewhere, flush out system good. then put anti-freeze back in and then change the coolant temperature sensor, also change the thermastat. good-luck!!

Have you replaced the right switch that mean the switch with the right temperature according for this engine.

check the temperature switch for power and test power at fan relay, you can also run wire from battery to fan directly and tap to see if fan works

maybe the water pump wasnt the problem to begin with. if the engine temperature only goes up when you stop the car then most likely it is the FANS that are not engaging to cool the radiator which is a problem with the fan sensor, computer that controls the fans, relay/fuse. I had the same problem on my 1999 cady STS coming back from my vacation. the engine temperature would be normal only when I drove the car above 70km/hr because the air passing through the front of the car would cool the radiator. when I slowed down the fans wouldnt start and no air was passing through to cool the rad, hence the engine temperature would start to go to HOT. good luck.

6
Accord Civic CRV CRX Del Sol Odyssey Prelude
85-98 86-98 97-98 85-91 93-97 95-98 85-98 ECT Sensor (Engine Coolant Temperature)
defective circuit or unplugged / defective sensor
10
Accord Civic CRV CRX Del Sol Odyssey Prelude
85-98 86-98 97-98 85-91 93-97 95-98 85-98 IAT Sensor (Intake Air Temperature)
defective circuit or unplugged / defective sensor
16
Accord Civic CRV CRX Del Sol Odyssey Prelude
90-95 88-95 n/a 88-91 93-95 95 88-95 Fuel Injector System
defective circuit or unplugged / defective fuel injector

check your wiring for dirty connections or broken wires, you may have wires that are rubbed through or connectors that are not making full contact. you will need an ohm meter and check wires for continuity. a wiring diagram will be needed.

Check the cooling fan switch. It appears your auxiliary electric cooling fan isn't going on when at idle. and engine temp increases. While you are driving, air is being rammed thru your radiator as you cruise along, so it isn't overheating, at idle, that isn't happening, and the fan should go on as the temp goes up. When the ac is switched on, the fan is being signaled to operate due to the heavy ac load on the cooling system.

i had the same problem, swap out the thermostat.
its like driving a new car after.