Marcins83

Hi all!

It's kind of weird what is happening to my car... A while ago I had noticed that I ran out of a coolant because of a leak - fixed. After that the car has started overheating when not moving after driving few miles. So I changed the thermostat, replaced the coolant and got rid of air bubbles from the radiator (jack stand the car, open the radiator cap, heating to the max, and run it like this for 25 minutes, than close the radiator cap and shut the engin off). What I noticed is when the temperature rises above the half of the gauge scale, the fan is not working... I have to run AC to make it work. Then the temperature goes down. Sometimes the fan starts when the temperature is below the middle range of the temperature scale, but once it's above I have not noticed it working.
How should I proceed with this problem, should I change the temperature sensor which is located by the thermostat, or should I do something else?

Matt_75

Attachment 83826What fan is not working? The radiator fan? You have a condenser fan and a radiator fan. Jumper battery power to the fan not working or jumper the radiator or condenser fan relay, whichever applies, so there's 12VDC available at the suspected bad fan connector.

Below is the honda service manual check for the fan motors. Says to basically hook each fan to the batter and see if they run. (A) terminal is on the left and (B) is on the right if you're looking at the fan jack.

Cooling System

Fan Motor Test

10-6

1. Disconnect the 2P connectors from the radiator fan motor and condenser fan motor.

Terminal side of male terminals

1. Test the motor by connecting battery power to the B terminal and ground to the A terminal.
2. If the motor fails to run or does not run smoothly, replace it.

Marcins83

It looks like the fan switch is not working properly. I have checked the relay by disconecting the cables from a fun switch and conecting the two cables together with a paper clip. The fan started working right away. Tomorrow I'll replace the switch and post pictures. Thank you for the answer.

Matt_75

You're welcome. Glad you found the problem.

Marcins83

I will replace the coolant again after installing the new fan switch. I found the description of how to bleed the radiator:
"Turn the heater controls to highest temp setting and defrost mode (if equipped with a/c)....remove the radiator cap on a cold engine and open the bleeder screw a couple turns ...located in the thermostat housing or upper radiator hose.....add a 50/50 mix of coolant/water to the rad until it gets to the top and comes out the bleeder screw. Close the bleeder and start the engine.....add 50/50 mix if and when the coolant level goes down in the radiator....when warmed up, open the bleeder screw and allow any air to escape until just coolant comes out...use a rag to catch any drips. Close the bleeder when just coolant comes out and top off the radiator....fill up the overflow tank as well if it is low. Stop the engine and replace the rad cap...restart and run the engine for a bit....move the heater controls though the range of temps....allow the engine to reach normal operating temp and make sure the temps don't fluctuate..(if you have a temp gauge)

Parking the vehicle on an incline with the front end higher helps...the point is to make the radiator the highest point in the cooling system...many modern cars have lower hoodlines which make the engine heads or heater core the highest point which can trap air pockets.. You may have to repeat bleeding a couple times with a cold and hot engine cycle to get all the air out....on some car models you have to remove one of the heater hoses briefly to allow air to escape...or install a flush tee with a cap that can be removed briefly to allow air to escape ."

Can somebody explain where is the bleeder screw, where is it located?

dodadnules

Hi All, I'm relatively new out here and have what I hope is a simple question. My daughter's '02 is pushing coolant back into the reservoir and out the overflow. After some reading and many tests, I believe she has a head gasket leaking or a warped block.

My question is this, there are all manner of snake oil products claiming to seal these kinds of leaks. Do any of them work?

The symptoms are constantly losing coolant (albeit slowly) and eventually, overheating on longer drives. She's carrying pre-mix coolant and tops off the radiator before driving any reasonable distances.

I would like to limp the car along a little longer but really don't want to spend $1,500 on it. It's got 170K miles.

Advice?

Marcins83

Sorry buddy but I have no idea... I am also new and still struggling with my overheating issue... Below is the description what I have done:

1. As you can read from my post below, first thing I have changed was the thermostat. The car was still overheating when on idle. I had to be in a constant move to keep the temperature in a right level.

2. After driving couple miles I noticed, that (when the AC was off) the fan would not start when the temperature gauge pointer was a in a middle of its scale, so I decided to change the fan radiator switch. I thought that might be the problem. Ewerything was ok when driving short distances... But the car was still overheating.

3. I decided to flush the radiator coolant. After that I have replaced thermostat again and refilled with new coolant.

So the following is happening after this change: car is not overheating when on idle ( when I first start engin). It can stay like this for a longtime time, the fan starts automatically when the engin temperature is little below its middle position. Looks like everything works fine so I took it for a 20 miles ride... When I stopped the temperature was little above the middle of the scale and the fan started working, but it started running just for a short while! It has not been running until the temperature went below the middle (when on idle). So the temperature started rising, I had to turn my car off to not overheat it...

There is no white smoke from my exhaust. I really have no idea what is the reason of the overheating... May be the temperature sensor is bad???? May be the pipe???? Is there a way to check it? What I also noticed is that my coolant was red when when drained out and. Please help me...

Btw I have noticed when I turn the key in my dashboard, but the car is still off, the engine sign stay still but right before it goes off it flashes 5 times. During a ride it is not on, not flushing. Any ideas???

Jonovanj

So my Civic started over heating out of no where. Never smokes or anything like that the temp just goes all the way to hot after running fine all day. I replaced the thermostat but still having the same issue. If I turn the heater all the way on it goes back down to normal. Anyone have an idea of what I should do next? Sorr Im new at this and any help would be great thanks!

sdaidoji

iTrader: (1)

leave the heavy stuff like the gasket for last, but there are tons of other stuff to look for in this links.

https://www.civicforums.com/forums/3...reference.html

g'luck

Motorheadcraig

I'm having a issue with bleeding the cooling system after I had flushed the system and replaced the thermostat. Note : coolent and thermostat are OEM.
This was done for preventive maintenance I've tried bleeding the air from the system after filling the radiator and the Reservoir by turning on the heater and running the engine at 2000 ram's the fans kicked on twice and the thermostat opened.
After a couple of days she started over heating again. I've checked for leaks and a possible blown head gasket. All were negative
Any suggestions

NDNV

Sounds like a blockage in the cooling system as in air in the system, a stuck thermostat, a plugged radiator from flushing. Still could be bad head gasket. Does the coolant level go down and you need to add?

Motorheadcraig

Yes the level goes down so I checked for a possible blown head gasket by checking the oil cap, looking for water coming out of the exhaust even checked spark plugs and cylinders for coolent all negative

Motorheadcraig

Is it possible I'm not bleeding the system correctly causing air blockage

NDNV

There are several tests for a faulty HG. Still could be bad even with your observations.


You should eventually get all air out of system. Search on proper bleeding of air. If you need to keep adding coolant, you have a leak or bad HG.

Motorheadcraig

Thank you for your info I will do some more research on proper bleeding of the cooling system hopefully this is the problem if not I wouldn't mind getting other test ideas for a possible blown HG
Thanks again for replying

Matt_75

Is your overflow/reserve tank full of coolant or blowing coolant out of it?

NDNV

A couple of tests for detecting a blown head gasket is a litmus test of the coolant (identifies exhaust gases in coolant) and a compression test of each cylinder. The first test would be the easiest and is the one the mechanic used to confirm my bad HG (along with the lack of heating from the HVAC system).

Motorheadcraig

Restore level lowers but no sign of coolent in engine compartment or on the ground

Motorheadcraig

Thinking coolent is replacing the air in system

Motorheadcraig

And wouldn't trapped air cause the thermostat to fail?

NDNV

Thermostats have air bleed holes. Did you install the thermostat correctly? Hole goes at the top and spring towards the block.


Keep cycling, topping up and checking to get the air out eventually.

Motorheadcraig

Yes thank you I just came in from a long test drive. It looks like the traded air is finally gone the temp gage stade at norm the heater still is blowing hot air and coolent is good in the resivore.
I thank you once again for all your help. In all of the years of maintaining my family's cars this Civic takes the cake hands down. I'm going to suggest this form to all of my friends and family and will do my best to help others when I have earned respect on a form like this