hey everyone! i'm new here on this accord forum and i'm seeking some advice on some trouble i'm having. i got my 1988 accord lxi a few years ago, runs fine and everything except when it gets cold outside the engine won't warm up while driving. It'll warm up to operating temp just idling and throw good heat out of the vents but as soon as you start driving in the cold weather, the temp gauge goes way down like if the engine were cold and i get no heat out of the vents. any suggestions what might be causing this BESIDES a thermostat (i've already tried that didn't help at all)? i've been driving my pickup when it gets cold but since gas prices went up i've been trying to drive my accord as long as i can stand the cold drive...and it sucks when the windows won't defrost while driving haha. thanks for the advice in advance everybody and sorry for the long post...just want to make sure i describe it as accurate as possible!

 

The description is classic for a bad thermostat (not closing properly). But it's new so ????

Unusual but not impossible to get a bad thermostat out of the box. What brand? Not sure about 1988, but later Accords T-stat housing is arranged so it's impossible to install it backwards or upside-down. Any chance of that?

How cold does it have to get (outside temperature)?

 

I bought the new thermostat from NAPA so whatever brand they have is what i got, i forgot the name of it (probably napa brand). I looked at the housing when i put it in to make sure that i couldn't put it in backwards so forth...the housing itself is tapered to fit the t-stat only one way. I suppose it could entirely be possible that i got a lemon t-stat out of the box...as far as how cold it has to be for it to act up this way goes, around low 40's and colder is when it does this...

 

Low 40s isn't cold at all. Unless you're talking MINUS 40 F...

Still sounds like a defective thermostat. I think a dealer T-stat isn't real stupid expensive.

 

I think it may be the t-stat as well, but if a new replacement doesn't do it, I would try looking at the heater valve. That is the valve (mounted to the firewall in the engine bay) that controls the amount of water that makes it to the heater core to change the air temp from hot to cold. Possible it is not opening fully??? Does your temperature slider **** move freely and all the way to the hot side?

 

Most techs on this site suggest getting a thermostat at the dealership, because it opens at the proper temperature. It is around $20 for the part.

If that doesn't fix it, I would start leaning towards the water pump.

 

Try a Honda T-stat.