1992 Oldsmobile 88 cant figure it out...

[quote:86fc7c8fbd="h1gh0nlife420"]Heater problem
1992 Oldsmobile 88 6 cyl Automatic 123000 miles

my heater works but only when the blower fan speed is set to high. occassionally it will start to work on all blower speeds but not very often. the weird thing is that the heat only gets hot when all the blower speeds are are working, otherwise the heat only gets hot when the car is idiling (either in park or in gear with my foot on the brake).

my guess is that its propably the thermostat but im not quite sure. is it common for a thermostat to sometimes work and sometimes not work?[/quote:86fc7c8fbd]

Hello,

Ok, Not quite understanding..... so a question and a suggestion for you....

Do all the fan speeds work? Or does only the High setting work. If only the high is working then it could be your Blower Control Module.

If all speeds are working then it could be your Heater Core is partially clogged and needs to be replaced. Or it could be a Heater Control Valve problem.