Justin Ripley

Ok so my 02 civic ex overheated. Got 3/4 the way up and I shut her down. Then I would wait 10 mins drive for about 30 seconds and it would shoot right for the red line.

so here's what I've done. Replaced thermostat and radiator cap from honda. Did a poor man's pressure test by taking off small line at radiator cap that goes to the over flow and put my air chuck to it. Go figure I have seepage at the timing cover.

I also noticed my fans aren't coming on. So I jumped relay and radiator fan turned on. Bridged the fan switch at thermostat and turned key to II. Fans both kicked on.....

now it has heat but the lower radiator hose is cold like the thermo hasn't opened. But there's heat which seems odd. The radiator started steaming. This could be from the fans not kicking on?

and also if fans aren't kicking on but when I bridge relay and fan switch they do. That says the fan switch is bad right?

Aside from the water pump seeping it's not overheating anymore. Gauge stays just under half. ...but the cold lower hose and fan switch are not settling good with me. I'm a mechanic and I want things right lol.

​​​​​​​any input would be great thanks

bbarbulo

heat is part of the block, so as the water in the block warms up, it provides immediate heat to the cabin. If we were to wait for the thermostat to open before heat was available in the cabin, there would be a lot of frozen people and iced over windshields.

so the rad hose is cool but the rad starts to steam? that's not a good sign, particularly since that wouldn't be steam coming out.

Justin Ripley

So last night I put a paperclip in the relay to keep the radiator fan going. Went for about an hour ride. Temp stayed right below middle. Did a variety of driving...slow in town roads to highway speeds. After about an hour I came home and let it run in garage for about another half hour....no steam. Also I should have been smart enough to realize this. I changed the thermostat. Added coolant. Obviously I got coolant everywhere taking off thermo housing. The steam was probably all the spilled coolant burning off.

I have also read that if the water pumps fail in this car it can prevent the thermo from opening. In return causing the fan switch not to kick on as well. So I am thinking a new fan switch and water pump/ timing belt will fix my issue. I have a small leak at water pump. Coolant isn't dripping anywhere else. Oil is not contaminated. My coolant is clean, and oil cap has no residue. I doubt it's my head gasket which I know is common. But I'm going to do the radiator test with that blue fluid to test for exhaust gases. But my coolant doesn't bubble is radiator when hot. Just a bubble or two every 5 seconds or so which is from the air getting in at water pump I assume.

like I said car runs perfect when I jump fan. No steam. Have heat. And gauge stays right below middle.

my car has 184k. I bought from an older church man. Gave a folder full of receipts. He kept everything that was done documented. The car was very well taken care of which is another reason I bought it. The thing that throws me off is I have a receipt of timing belt and water pump being replaced in august 2015 with honda parts. This was 38k ago....water pump already failed? Does the dealer have junk water pumps or something?

1992BB2

If your fans don't ever kick on, and bridging the switch connector keeps the car from overheating, it sounds like:
1. The coolant isn't circulating past the switch good enough. (Which could be your thermostat being stuck closed, water pump, or possibly a blockage somewhere in your coolant system.)

or

2. The switch itself went bad. Which in my experience, these don't go bad very often. They respond to a certain temperature, and complete the circuit for your fans to run, once there. A pretty simple design.

Justin Ripley

Well this past weekend I changed the water pump timing belt and tensioner all with honda oem. The fans still did not kick on. Bled cooling system with radiator cap at highest point. Bled for about 45 minutes until finally I had no more bubbles. Put cap on. And I had nice hot heat. No visible leaks. Took it for a ride and temp started getting a Lil above half. Pulled over and found fans were not on. So I put the paper clip in the relay and kick on the radiator fan. (Just one fan running not both)

temp stayed just under half with no issues. Went for about an hour ride. Next morning I checked coolant level and radiator was still full and overflow was in between min and max. Jumped relay to kick on radiator fan and headed to work. I noticed once the heat went to cold when I came to a stop but went back to hot as I started going again. I get to work and open the hood to take out paper clip and see coolant sprayed everywhere on engine. It's clear it came from the overflow which was now below min line. Radiator was still full.

so it never overheated. Temp stayed right below middle. I had heat except for when I stopped once. And boiling coolant out the overflow. I hate to admit to it but I think my head gasket needs a change. Thermostat radiator cap and water pump all new from honda. Either clogged radiator which I doubt or head gasket......was hoping I wasn't a victim but I assume I am. Luckily these cars are easy to work on.

​​​​​​​but I've been driving it all week. Still hasn't overheated. Temp Goes Hot To COLD When I Stop AND go. total coolant loss since Sunday has been 1/4 jugs worth. Keeps blowing out overflow....not much but enough to where the fan sprays it every where and soaks everything

1992BB2

Yikes. Well, if I were you, I wouldn't keep throwing parts at it. Use a testing kit that screws onto the radiator cap hole to test whether any exhaust fumes are in the coolant. I still don't quite understand how a blown head gasket would prevent your radiator fans from kicking on. Especially if the coolant coming out of the overflow is boiling.

prodjay10

When you bleed coolant, make sure you have the heat on. That way the air comes out of heater core also.

in my experience with head gaskets, the block tester won't help unless it's a huge leak. Usually the leak is small and won't occur unless you're at highway speeds for a while.

Justin Ripley

Yes I had heat on full blast/ defrost with front of car up on ramps. I've bled hundreds of cooling systems but this one is just odd.

so I've been driving it all week and here's what I've noticed. Once the heat started going up above half way. I was in 5th gear doing about 50mph with rpms around 2200....I down shifted to 4th so rpms were at around 3k. Instantly the heat shot back down below half. In past 4 days I've had to add about 1/4 jug of coolant. It doesn't spray out overflow everytime. Yesterday went to work and back which requires me to drive on highway for about 8 miles. Didn't blow out overflow and my heat is hot.

it's just odd that if I keep the rpms above 3k it will not overheat, will not gush out and I have hot heat. Somethings telling me I have a small clog somewhere.

top radiator hose is hot, bottom hose is cool and the lines that go into back of motor to heater core are hot. So I know coolant is flowing through system and heater core just fine...no wetness on passenger side floor board either to heater core is good.

figure I'll just run it till it won't stop overheating. But I'm going to try to bleed more air today. I'm almost certain I need a head gasket, it's just the way things are happening it's throwing me a curveball. Runs great still....and even when I start it in the morning the heat is hot at idle. But after driving in town (low rpms) the heat will go cold. As soon as it goes over 3k rpms I have hot heat again.

puzzled..

and also when I took off radiator cap with it up to temp. It was bubbling pretty much constant and when I hit the throttle it would blow out radiattor.

Justin Ripley

Well I just took her for a ride...Tried to get it to overheat. Wouldn't do so..drove in town, highway no overheating. Heat stayed pretty hot the whole time.drove about an hour and a half and come home. Open hood and overflow is still near max line and radiator is full.....this is really odd.

by the way there's no coolant in oil, no residue on oil cap. Coolant looks Clean, no sign of contamination. And I have a very light white smoke out exhaust. Barely visible but it's kinda cold here so that's why I'm seeing light white smoke. When up to temp there's little to no smoke out tailpipe.

this is puzzling me bad. And I still have to jump my radiator fan when I drive it. So I know fan switch needs to be replaced.

I've also read that the best way to bleed the coolant is to actually take off the fan switch and fill until coolant comes out the sensor hole then put sensor back in and run with heat on. Going to try that next if it overheats again. But as of now it's running as it should with no leaks anywhere

1992BB2

Instead of jumping the relay, try jumping the switch itself. Unplug it and run a paperclip from one hole to the other in the connector. The fans should come on. If not, then the switch is fine. The relay itself is the next thing I would suspect based on what you've said so far.

And also, the best way to bleed the cooling system, is to use the bleeder valve. Not sure why anyone would tell you that, but you'd have a hard time bleeding it sucessfully through the ECT switch port, I would imagine.

Justin Ripley

In my previous post I had said that when I jump the relay the radiator fan comes on. Only one fan. When I unhooked the ect and jumped it BOTH fans came on. So I know it has to be the switch.

also I've read there is no bleeder valve on my model year. And trust me I've searched for one anyways. No bleeder.

​​​​​​​and yesterday it got warmer in the afternoon. Was about 38*. And I had absolutely no white smoke from tailpipe when warmed up.

lars6291

Seems like even after verifying Fan Relay, Fan Switch, Fan operation and bleeding coolant system my 02 Civic seems to run right on the edge on temp. You would think a 10 deg lower rated Temp Switch would be better by kicking fans on earlier and longer. Is this possible without making any drastic changes in computer software?

Justin Ripley

it's the thermostat that has the varied degrees...ie. 180* Stat or 195* stat....it's not the fan switch with temp differences.


also as for my civic....it's been a week, haven't added any coolant. No boiling over. No overheating and I have heat....guess it decided to fix itself...weird

​​​​​​​still jumping my relay tho...be busy at work this week so I'm Gunna change fan switch tomorrow and see if it fixes my fan issue...if not it's on to pin point testing which is annoying...

lars6291

Thinking installing one of these any opinions? http://www.americanvolt.com/Adjustable-Thermostats/32-250'F-Adjustable-Dial-Electric-Fan-Thermostat-Controller-40A-Relay-Wiring-Kit

Justin Ripley

Well I've been driving it no problem past couple weeks...only bad thing is when I come to stop Heat would go cold....then back to hot as I drive...

today I replaced fan switch finally. Both my fans are working now. Also changed my cam plug cuz she was leaking some oil. In a week I lost about a cups worth of coolant.

got it up to temp and fans were kicking on and off. And I took rad. Cap off. Had few bubbles going. So I block tested it. To my amazement the blue fluid didn't change color. I thought for sure my head gasket was blown.

so there's a leak somewhere. I have new water pump, rad. Cap from honda, new thermostat from honda. Verified jiggle valve is at top and gasket isn't pinched. Pressure test didn't show any leaks.....hopefully now that my fans work I'll be good to go

Justin Ripley

M Glen Miller

I have a 2006 Honda Civic LX.... I first saw a check engine light come on. Started with a P0128 fault. I changed the Engine Coolant Temperature sensor on the thermostat housing, and I changed the thermostat. I now got a P0111, and a P2183 fault code. My cooling fans are turning on at around 217, 220 degrees F, and knocking it down 10 degrees F. I burped that car for an hour after the thermostat change today. I will be changing the Engine Coolant Temperature 2 fan relay tomorrow. Hopefully that should fix my late fan problem.

M Glen Miller

I installed the new Engine Coolant Temperature 2 sensor(ect2), and the fan is now coming on at 200 degrees F, and is running properly. The ECT2 I removed from the car's radiator was an incorrect sensor. I bought this car 7 1/2 years ago from a local Honda dealer, and it was recertified. Seems someone installed an ECT1 sensor in the radiator, and it was running hot for years, and I didn't know why until the fault codes came up. I'm lucky the head gasket didn't blow, or the block didn't crack.....