Date: Sun, 17 Jun 2001 20:41:12 -0600 From: "RONALD M FRIESEN" <rfriesennopsamigy.net> Subject: Re: '91 Saab 900 overheating
I just fixed a somewhat similar problem on my '87 900S. According to the Bentley manual there doesn't seem to be any essential differences from '87-93 but I think they changed the wiring so that whereas my fans both run when cooling, AC on or not, they changed in '88 or '89 so that only the left comes on when cooling. My temp gauge went almost up to the red. I first changed the fan temp sensor - it made no difference. My hoses seemed to be hot so I thought the thermostat was OK. I was advised to change the thermostat and it fixed the problem. It seems the actuating mechanism involves a cylinder filled with wax, if part of that leaks out the thermostat won't work properly. Go to http://216.78.173.190/entry/tech_doc_systems.htm and read everything there about cooling - I wish I had found it before today. I was advised to install a 82 degree C thermostat - I should have also installed an 82 degree thermal switch for the fans. I was also advised to install phosphate free silicate free coolant (Saab approved) Maybe the above site will give you a clue about why the left fan isn't coming on. Ron Friesen 87 900s 3dr manual 76 99 (not running right now) "Tony" <NOSPAMtshiminopsam.com> wrote in message news:3B2CC3E2.8394644Anopsam.com... > Replace the radiator temp sensor. As to why the left fan is not working, > you may want to re-check that you inserted the fuse O.K.; but it also > may need some time (minutes) before it restart. > > And for Sure replace the strait water with good coolant fluid. > > Brian Dean wrote: > > > I have a 1991 Saab 900 with the 2100 cc engine, manual transmission and ac. > > > > Beginning yesterday the engine temperature gauge is indicated "HOT". > > It has never done this in the past couple. > > When this hot condition was notice, we added about 2 quarts of water to the > > coolant reservoir. Since then the coolant level has not changed and their > > is no evidence of leaks. So I am assuming the slightly low level is > > unrelated. After running about 10 minutes it is "HOT" and I shut it off. > > > > The v-belt on the water pump is fine. and the pump seems fine. > > > > The thermostat was my next thought, but the upper return hose on the > > radiator is hot ... so I am assuming that the thermostat is open and likely > > working fine. > > > > The fans seems suspect to me. When I first noticed the Hot condition only > > the left fan was working (left from the drivers seat position looking > > forward at the fans). I assumed the right fan only worked when the air > > conditioner was on so I turned it on and it still didn't spin. I check the > > fuses (number 6 and number 25) and they are fine. > > > > Not sure why ... but I pulled out the fan low current relays (both of them) > > and they looked fine (???) so I stuck them both back into their sockets. > > > > When I started it the car ... now neither fan was turning... and the engine > > is hot and the air conditioner is on. > > > > So I jumped out the radiator temp sensor and the right fan starts to spin... > > so I am thinking perhaps the radiator is not hot or perhaps the radiator > > temp sensor is shot... and I am still wondering why the left fan has decided > > to stop running ??? > > > > Any ideas or know issues that I should be considering??? > > thanks, > > Brian > > > >
 |
 |
 |
 |
 |
