eqalias

Sorry if this is a repost of a repost. I've been searching the forums but I want to be clear on my answer.
I have a 1998 Honda Civic that is overheating. Here's the exact steps I've done so far.

- fan wasnt turning on. I replaced the panel fuse with a spare in the engine bay, no change
- I unplugged the fan wire connecting to the cooling fan switch (that connects to the thermostat housing) and hotwired the fan with a paperclip. the fan runs fine when hotwired
- I was thinking thermostat but the nice guy at O'Reillys said it was the fan switch (that connects to the thermostat housing). I replaced that and the fan still does not kick on
- I drove the car with the fan hotwired on all the time but the car still overheats
- coolant level looks to be fine

Is it possible the thermostat failed in the closed position and is not only causing the overheat but also for the fan to not engage?

oy vay

choppyEG

You most likely have a stuck thermostat. I would recommend replacing it and your radiator/heater core hoses while you have the system drained (use new hose clamps too). Coolant flush and change couldn't hurt either if you haven't done that yet. If you are still over heating then your water pump is probably not pumping coolant. Could also be a clogged radiator, with the car warm feel the front of the radiator if part of it is hot and part of it is cold than you have a clog.

crxsi1

Check the cap also... if its not holding pressure correctly it will not cool correctly... I would check that first as its cheapest and then the above... and if thats not it... I would also say the thermostat... if you take it out and boil it to the temp that its rated it will open. If it doesnt then you'll know that was your problem... sometimes it will stick open and wont allow it to build pressure properly and that can cause it to over heat also...

CO671

iTrader: (1)

Usually a proper coolant system bleeding would be the first thing to do
If you've done that, then check for any leaks, or check the radiator cap that it's not damaged.

If those are still fine, Run it until its hot.

Now feel the upper and lower radiator hoses



If the lower hose isn't as hot as the upper (or even warm at all, just cold) then it's most likely your thermostat. Simply get a new thermostat, a thermostat gasket, and some RTV and install it.

If the problem persists, it may be a headgasket, which is very common with Civics from 92-00.