My 91 Accord, although sinfully ancient was running fine. I had a new radiator installed about 3 years ago and most of the hoses replaced, as well. Last night I attempted to turn on my heater but it would only blow cold air. I made sure the ***** were all working properly and that the a/c button wasn't pushed, etc. I figured it was an electrical problem or something (my car has a poltergeist, really). After about a mile I noticed a little smoke coming from the engine area. Not a lot though, like when my radiator cracked. Then my temperture gauge jumped off the dashboard. It was much too dark to see what was happening and where it was coming from.I was hoping that one of you might recognise the symptoms before I take it in for repair. Thank you!

 

at first thought it sounds like a stuck thermostat, did you shut it down the moment you noticed it getting hot? did it get into the red at all?

 

I'm going to expand on my answer for a second. When the thermostat locks closed it doesn't allow the cooled air from the radiator into the engine, which in turn prevents it from circulating coolant through the heater core so you won't have warm air. I've personally seen it/had it happen on more than one car, the steam you saw could be from the overflow tank, coolant bubling out/through the radiator cap from to much pressure or a few other spots. If you ran the car for any amount of time when it was in the red then you need to check your oil and make sure it doesn't look milky in color at all, make sure that your coolant is full then in the morning before you start the car pop the radiator cap off and see if there is a rainbow looking film on top of the coolant, if either of these conditions exist you may have blown your head gasket and/or warped the head from over-heating, if they don't exist then you may be able to just buy a new thermostat and replace it, buy honda OEM for this, cheap part but if it fails and you don't catch it then it can cause a lot of damage.

 

just to be a nitpicky PITA, I'm gonna correct 1 thing ....... the thermostat allows or disallows cooled WATER from the radiator to flow into the engine. [sm=gobble.gif]

 

*ROFL* I just saw that I typed air for some reason... nice catch!

And if we REALLY want to be a nitpicky PITA we'd say cooled COOLANT or ANTIFREEZE

 

My first inspection for no heat is, IS the radiator full and the overflow bottle up to the full mark. There is a heater shut off valve on many cars that blocks flow of coolant in the heater hose going through the firewall, some are mechanical and some are vacuum operated, see if this works also. Then with a bad tstat, I like to start the engine up from full cold and monitor both radiator hoses, the top hose may get hot but the bottom hose may never really change, this can take up to an hour so be patient. If the cooling fan does not come on for a long time during this test also, then it is likely that the tstat is bad.