Effect Does not blow hot air at idle Symptoms The car temp gage will point to slightly less than half way and at idle, blows cold air Will blow warm air (not as hot as it should be though, just warm) when the engine is under load Coolant leaks from under car Cause? Could it be a bad thermostat stuck wide open? Would that cause these symptoms? Any car buffs out there? The hoses looked fine from when I checked them recently, no corrosion stains, no wetness, no dry rot type stuff as far as I can tell Any other possible causes?