Brandon Beja

Hey guys, new to this forum and not sure if it's in the right place or not.

I have a 1995 Honda Civic Dx that when driving, never overheats. When I stop in traffic for more than 10 minutes, the temp gauge starts to creep slowly. This car really has me stumped as I put a lot of money and time into it already. Things I've done: head gasket, spark plug wires, spark plugs, distributor cap and rotor, replaced all belts, water pump, radiator, upper and lower hoses, oil pan gasket, flushed the heater core, changed the thermostat, replaced the two temperature sensors (under distributor), new exhaust, brand new coolant and oil (obviously), radiator cap, fuel filter, air filter, and changed the heater valve. I do not have any milky residue in the reservoir or on the oil cap. I do not blow out any white smoke.

I did the parts in phases as the radiator, flushing, sensors, and oil pan were just done as the last projects. Now the check engine light is on, I jumped the wire under the glove box and it flashes the check engine light 6 times which is the water temperature sensor. I just changed that freaking thing. I changed the sensors thinking that would help my issue of the gauge fluctuating.

Along with the check engine light, the engine has a tough time starting (which it NEVER had before) and it used to start right away with no hesitation. The battery is an older battery (not sure how old) but it holds a charge, and I checked the battery and the alternator with a volt meter and everything is normal output. The fuel pump I hear working when I turn the key to accessory, so I know that's ok.

I'm just stumped and I'm hoping some of you car gurus can help me out. This is my daily driver for work and I kind of need it. Besides this new issue of having trouble starting, the car runs perfect.

CFiannotti

When you stop, and it starts to gain temperature, do you hear the fan kick in?
When the temperature rises, can you use the interior heater to lower the temperature?

mk378

Put your old ECT back in if you still have it. They can be checked with an ohm meter and the resistance versus temperature chart found in the service manual.

Make sure cooling system is full (check in the radiator when cold) and you always get hot air from the heater, both idling and moving. If that is true, then overheating only when the car is not moving is almost always fan related.

The fan is controlled by a temperature switch on the thermostat housing. Unplug this switch and jump the plug on the harness side. The fan should now start immediately when you turn the key on and stay on all the time the key is on. If it does not you need to check the fan motor, fuse, and relay. The fuse and relay are in the underhood fuse box.

If the fan does start, test drive with it running all the time and confirm no overheating. If it doesn't overheat with the fan jumped to run all the time, that means the switch is bad.

Brandon Beja

to answer the first question, I cannot hear the fan with the engine running. When I put the heat on, the temp gauge comes down. (did this the rest of the way to work).

I threw away the ECT and if I did have it, the plastic connector on it cracked so it was no good anyway. The radiator was bled properly and no bubbles were showing anymore so I know that there was no air in the system. I jumped the fan, like you said, and the fan stays on when I turn the key to acc. No fuse was blown, and I heard the relay click when I turned the key to accessory with the fan jumped. I do not know if the relay is bad (I don't remember how to test them with an ohm meter). Its possible it is.


any reason for the car having trouble starting? Could it be the cold weather? When I started it today the first time, I hit the gas thinking if I gave it some fuel the engine would crank and start. The engine just died. I started the car again and it finally started and took it for a drive and no issues.

Thanks again for the help, and sorry for the late replies. The website wasn't working for some reason when I tried to respond the post.

mk378

Bad ECT can make the engine hard to start. Again, check it with ohm meter. Don't expect the car to work properly with the CEL on.

If the engine does not overheat with the fan jumped and running all the time, the thermo switch must be bad and not turning the fan on when it should.

Malt-liquor

Check if your fan is working and bleed your coolant with front end jacked up.

Brandon Beja

are the two sensors the (one on T stat housing and under the distributor cap) the same? i cannot find different sensors online.

Brandon Beja

I have bled the coolant with the engine warm and both hoses warm, no air bubbles left coming out of the bleeder.

mk378

No they are not the same.
Honda Automotive Parts
The ECT is part #17. The fan thermo switch is part #16. They have different thread sizes, the thermo switch is much larger.
Did you test drive with the fan running all the time and confirm no overheating?

Brandon Beja

I changed out parts 15, 16, 17. Also changed out the fan relay. When I get home, I have to bleed the coolant again and refill. Did not have a chance to do so yet. I have not test drove with the fan running all the time as of yet. Once I bleed the air and refill the coolant lost, I will try it out. Even after changing out that sensor, I still have a check engine light on and it is still hard to start.

Brandon Beja

I still have not run the car with the fan running all the time. However, I just let the vehicle run for 20 minutes and then fan finally turned on, but for only 10 seconds and then turned off. Temp gauge was in its normal range. The car still has a real tough time starting though.

Brandon Beja

Alright so the car isn't overheating anymore. I believe the fan is working again after the last sensor change. The car is still having trouble starting and I still have a check engine light with the code flashing 6 times still. Any reason this is still happening? Any way to clear the code? I pulled the ecu fuse and nothing cleared.

sorry to keep going on with this issue