I have a 1998 Honda Accord Dx(?) 4 cylinder vtec. It has 185k miles on it. I just pulled in to my garage and noticed some white smoke/steam coming out from the radiator under the hood. My a/c hasn't been working for a few weeks. I was driving on the highway from work to home and not in stop and go traffic. I investigated after a few hours, both of the motors didn't switch on after it got up to temperature after running for 5-7 minutes. I then jumped the thermo switch A with a paper clip, and the fans started spinning right then and there. The plug has power, as I checked it with a circuit tester. I replaced the thermo switch A which is on the thermostat housing. It still has this problem, the fans do not run unless I jump the circuit with a paperclip.

I refilled it with coolant in the reservoir and the radiator, replaced the thermo switch A, and then started it up again to check/test. I noticed that there isnt any more coolant in the reservoir or radiator, but it didn't look like it has been leaking on the floor/underneath the car.

Does anybody have any ideas as to what I should check/try next? I was thinking probably the thermostat and flush and fill the coolant system. Is it even worth it, is the head gasket blown?

 

you said you waited 5 to 7 min? wait longer to see if they come on or not first. then if it starts to get hot and doesnt come on check other sensors.

to check for a HG wait till morning on that first start of the day and see if white smoke is coming out of the exhaust and if your coolant is low. also check hoses and cap. GL

 

you sound like you know your way around cars, so could be anything from a loose hose clamp to a head gasket.

For the latter I'd do a 'hey, you drive my car so I can watch the tail pipe,' followed by a compression test if white smoke shows.

 

Checked the exhaust first thing this AM after it sat all night....no white smoke, seemed just fine. I'm leaning towards replacing the thermostat and then a complete flush of the coolant system. The hoses were soft, not brittle, the thermo housing had some coolant in it (I saw inside when I replaced the thermo switch A), so maybe it's locked in the closed position and not allowing coolant to cycle.

My plan is to replace the thermostat with Honda OEM, then the ECT, and thermo switch B. Then fill and bleed, then hope for the best. If that doesnt fix it, then a compression test I guess, but the car isnt worth that much, so trying not to pay a mechanic...

 

to save some money us a ohm meter or a volt meter to check the sensors, the one on the t-stat houseing i believe you have to check warm, and the two pin one under the dizzy i believe you have to check cold then warm. cold it will be at like 2000 ohms or something then warm it should be around 180ish

 

I dont have an ohm meter, and it's cheaper to replace the switches than to buy one. I'll change the thermo and ECT and report back. Hopefully it just overheated due to a stuck thermo and that's it. No white smoke in the AM, no milky colored oil, so HG should be ok...knock on wood...

 

A simple volt/ohm meter can be had for ~$10.....and the things it can do for you/save you in the future are more than worth it IMO.

 

I had similar problem....see my post last year...

 

OK, so here is what I've done:

1) Replaced thermostat + rubber seal
2) Replaced temperature sender/sensor
3) Soldered a power jumper on the heater/ac control unit

So the heater/ac control unit stopped working 6 weeks ago, and that meant that the fans stopped running, too (I guess). Today I replaced the thermostat and bleed the system, and it didn't overheat, but I did see some white whispy smoke coming from the engine bay. It didn't overheat, and it ran fine (after choking a little initially on startup after the thermo replacement).

I turned the engine on, and the heat all the way up to hot and the fan on full blast. THe fans never came on, and the air out of the vents never changed in temperature, meaning it never got really hot when i set it to hot and it didnt cool down when I moved it to cool. So from there I investigated the heater/ac control unit.

Then, I saw over on driveaccord.net there is a post about a guy soldering a jumper on the heater/ac unit to get it working again. Mine was not working, ac condensor not switching on, no lights, etc. So I soldered that jumper on. Now, it works, which is great. So I turned on the heater all the way to the red, fan on full blast, and sure enough it got really hot. I ran it like this for 20 minutes, and it didnt overheat, I didnt see any smoke or anything, and then I turned the ac to cold, and sure enough it got cold.

So now I'm not sure if it's fixed or not. The fans run, the ac works, it gets hot when i dial it to hot, it gets cold when I dial it to cold. AC compressor works and switches on, fans switch on with the compressor engaged.

I think I bleed the system properly, but I dont see any fluid in the bleeder tank. I Filled up the radiator to the top on the radiator and just put a touch in the expansion tank. To bleed it, I opened the bleeder valve, filled the radiator slowly with coolant, then when it started coming out of the valve, i closed it and put the cap on the radiator. Then i turn the car on, heat on full blast, ac on, fan on high and ran it like that for 25 minutes. Needle stayed right in the middle, just below. Didn't overheat, no white smoke from the exhaust, checked the oil it looked fine, not milky or anything.

So, any thoughts? I'm gonna let it sit overnight then fire it up tomorrow and check for leaks, try and see if I bled it properly, and cross my fingers. Anyone see any glaring issues or any "gotchas"? THanks guys.

 

I had the same issue and it was only a thermostat but it took the mechanic too long to realize that was the only issue and in the interim with the overheating I had the radiator ( which was under warrantee because ihad it relpaced about 8 months before) replaced ( no cost to me) but they told me the fan needed toi be replaced...very expensive. Who knows maybe the were just out to get some cash back on teh labor from teh free radiator...anyway after that I still had issue and took to another mechanic it wsa the thermostat.