1992 Saab 900 s N0 heat

in article snipped-for-privacy@localhost.talkaboutautos.com, PAPAGENE4JACK at snipped-for-privacy@msn.com wrote on 02/09/2006 19:41:

Blocked heater matrix would be the obvious one ... Check the large coolant pipes above the water pump for blockages. Give 'em a squeeze. Perhaps drain out some coolant and take them off to see if you can flush through the heater matrix.

I suppose the other thing is the heater rod has become detached. Does the heat selector feel easier than usual? Remove the LHS speaker grille on the dash and look for a long rod that attaches the heat selector to the heater matrix.

Happy hunting :) Report back,

Paul

1989 900 Turbo S

The thermostat is designed to divert all coolant to the radiator when the temp is at full red, therefore none flows to the heater core. If your thermostat were working well, you wouldn't be getting to full red in the first place. If I were you I would replace the thermostat with the 82 C version, and maybe also the radiator and fan thermoswitch (also 82 C to match thermostat).

John

Thanks for the reply Paul. I noticed that as car I drive for maybe 10 or

15 minutes I have full heat,then gradually it starts to lose heat and go to warm even with temp on full red. Could this be my thermostat which I believe to be original with 150k. Thanks again papa

Thanks for the input john,but when I referred to full red I meant the heat dial on the dash not the temp guage. The temp gauage only get up about one third on the red. In the past it usually runs about three quarters and just lately it started to run at about one third. thanks again papa

Hmm, so maybe your thermostat is stuck mostly open. At 150,000 miles, it's due for a replacement anyway.

John

Replace the heater valve.

thanks for your help John,Paul,and darthpup. The problem was the thermostat I replaced it today and heat is restored. Again thank you for your help papagene

Guys can you just tell me what and where the heater matix is. Is this the valve that the hoses all attach to? thanks papa

No, the heater matrix is the radiator looking heat-exchanger thing that the hot coolant goes through to transfer heat to the air. Some call it a "heater core". Can't say where it resides in a C900 though, sorry.