I have a '92 Saab 900s that has a problem with the heating system. While driving the vents produce a warm flow of air but not enough heat to warm the car. While idling the vents do not produce any heat. I have also just recently noticed that the thermostat gauge is not centered but instead reads half way between centered and cold. The coolant level is fine but maybe 3-4 times this year I have had to add a small amount to the system. Are there any ideas of what may be wrong with the heating system?

-- Eric Sloan (ericsloan@mediaone.net), December 19, 2000

Answers

There are two different coolant temperature thermostats. Make sure you have the one with the higher opening (=operating) temperature. Also, check the heat exchanger which heats the vent air. But: I had a '92 900S with the same problem which finally disappeared after all coolant hoses had been exchanged (!!). Independent of the heating problem, coolant hoses should be exchanged after so many years of operation as a preventive measure. Old hoses tend to leak, results often catastrophic for the engine. I am German, therefore my English ... All the best to you. Even with leaking coolant hoses the sex appeal of a '92 900S is still unsurpassed. KS

-- Karsten Simon (karstenpg.simon@web.de), April 30, 2001.