engine overcooling?

General engine questions/issues that aren't specific to the other categories
 Reply
User avatar

engine overcooling?

By JUICE
- Sun Dec 05, 2010 11:17 pm #226196 a guy on my local forum is having a problem i've never heard of. curious to see if you guys had any insight on this

What would cause engine to not stay warm(other than thermostat?)
I ve had this problem since i bought this car 3 yrs ago. Bone stock 96 civic It runs great in the summer, doesnt overheat or anything, no check engine lights. But in the winter, anytime its 40 degrees or less outside, the car will not stay warm. If i sit there and let it idle, it will get up to operating temp, but the minute i start driving the temp gauge shoots to COLD. And i have no heat.
I have had 3 different thermostats in the car two 180 degrees and now a 190 degree. The 190 degree helped out a little bit, but it still wont stay up to operating temp. It has new coolant, new plugs, timing is accurate, no air in the system from what i can tell.....
What else would cause this thing to not stay warm?? I have been blocking off the radiator with cardboard for the past few years, haha......


only thing i can think of is that it has a Z6 block with a Y8 head. Did the Z6 block come with a different water pump that flows more(less teeth?)ect... head gasket difference???
User avatar

By TrailerTrash
- Sun Dec 05, 2010 11:45 pm #226198 mine is the same way only it doesn't get down to cold on the temp gauge. when it sits and warms up the needle goes to half way like it should then when i start driving it goes down to half of that. like 1/4 of the temp gauge. sometimes when its really cold i can drive for a week+ without the fan even kicking on. it sucks cause the heat in the car is lousy. i usally move my front plate over in front of the radiator to shield it from the air so it stays warmer.
User avatar

By asianrob
- Mon Dec 06, 2010 12:20 am #226199 mines doing the same thing. its the thermostat. im too lazy to change mine out.
User avatar

By OleFolk
- Mon Dec 06, 2010 1:09 am #226207 Same thing here my car cannot warm up by just idling
and when it does idle it revs (low,high,low,high,low,high) like its panting

Il drive around and it will warm up but then just go all the way back down
Im not too worried about it I survived last winter EG's are beasts in snow.
User avatar

By asianrob
- Mon Dec 06, 2010 5:51 pm #226306
OleFolk wrote:Same thing here my car cannot warm up by just idling
and when it does idle it revs (low,high,low,high,low,high) like its panting

Il drive around and it will warm up but then just go all the way back down
Im not too worried about it I survived last winter EG's are beasts in snow.


if your idle is doing that id look at the IAC on the underside of the throttle body. adjust it and see if bad idle goes away.

i think i may change my thermostat to see if it actually does fix the problem.
User avatar

By ghskid06
- Mon Dec 06, 2010 6:01 pm #226308 yea mine does the same thing, heat still works great though. Kicks in pretty hot after the cars been running about a minute. I assume it is my thermostat, it took forever to get up to operating temp when it was warmer, now with this 20ish degree weather it never goes above the cold line, if my heat wasnt still working i might actually have done something about it by now. (assume its sending every bit of warm coolant strait to the heater)

As far as his heat not working, he might have a clogged heater core or something. His coolant should heat up if his thermostat is working properly. Is he sure hes sealed it well? Has he tried one from honda and not autozone?

Edit: Even if his water pump was different, his thermostat would still allow the car to heat up to normal temp before it opened.
User avatar

By Eg6H2D
- Wed Dec 08, 2010 9:47 pm #226756 Yea guys that means ur thermostats are faulty stuck open allowing the coolant to flow freely. change those and it should fix the issue. unless they are running with no thermostat..

:thumb:
User avatar

By matt is (eg6)
- Sat Dec 11, 2010 3:39 am #227227
asianrob wrote:
OleFolk wrote:Same thing here my car cannot warm up by just idling
and when it does idle it revs (low,high,low,high,low,high) like its panting

Il drive around and it will warm up but then just go all the way back down
Im not too worried about it I survived last winter EG's are beasts in snow.


if your idle is doing that id look at the IAC on the underside of the throttle body. adjust it and see if bad idle goes away.

i think i may change my thermostat to see if it actually does fix the problem.


mine used to do that i bumped the iac on the fire wall when i was doing my swap and bent where a hose conects and it did the jump from 1k to 1500
User avatar

engine runs cold with heater on

By the-hag
- Mon Dec 13, 2010 2:08 pm #227623 My '93 del sol is doing the same thing, the heat still works but is not the greatest, and the hotter and harder the heater is on, the colder the engine temp gauge reads...When it's on full blast and high heat the engine reads stone cold. I don't mind the engine running cool if it isn't going to cause any damage, but I don't want to be stressing my engines for the sake of a thermostat. I just bought the car, and the guy said the thermostat was just changed but maybe it was a cheap one, and isn't working properly? It's also got a cold air intake, I could try putting the stock a/i back in as well maybe, my '94 hatch is parked with a warped head so I could use that one I suppose? It would be great to have some solid info from someone who's gone through the same thing before i waste money at the shop or cause harm to my new baby. Thanks for the help guys!
User avatar

By JUICE
- Mon Dec 13, 2010 2:36 pm #227624 ^ a piece of cardboard in front of the radiator will help some. the stock intake would probably also help...

and thermostats are cheap and easy to change.. never hurts
User avatar

By the-hag
- Mon Dec 13, 2010 3:33 pm #227631
JUICE wrote:^ a piece of cardboard in front of the radiator will help some. the stock intake would probably also help...

and thermostats are cheap and easy to change.. never hurts


Awesome thanks I'll do the cardboard and stock intake and go from there. Should I be worried about a cold engine? I've been leaving my heat off or on very low to keep heat under the hood haha
User avatar

By OleFolk
- Thu Dec 16, 2010 9:19 pm #228366 Actually now its so cold it just pulses when it idles
From low to high rev constantly even when im rolling at idle
Its probably not from the cold
User avatar

By lsvbeghatch
- Thu Dec 16, 2010 11:24 pm #228386 same prob before i bled out my cooling system and let some fluid out and now she runs warmer and heat is alot better!
User avatar

By OleFolk
- Thu Dec 16, 2010 11:38 pm #228391
lsvbeghatch wrote:same prob before i bled out my cooling system and let some fluid out and now she runs warmer and heat is alot better!


Ima go do that right now thanks :thumb:
User avatar

By lsvbeghatch
- Thu Dec 16, 2010 11:59 pm #228395 No prob. Its one of those things no one thinks of because its common sense lol coolant=cool. Less coolant=less cool but still efficient lol :woot:
 Reply
Return to Engine - General