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Discussion Starter · #1 ·
Hey guys,

My car 2002 9-3 has been running great.

Although I just noticed as the temperature has been dropping I am having a hard time keeping the temp gauge on my dash at 9:00.

It is fine if I have the Manual climate control on cool but as soon as I turn it to heat the heat starts to blow and the temp gauge needle drops.

Possibly stuck thermostat?

Thanks
 

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Discussion Starter · #3 ·
Well i replaced the thermostat and temp sensor. Still doing the same thing any other idea?

I am quite stumped and frustrated
 

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Discussion Starter · #5 ·
My fan has not come on since the cool started and it has been under 20 degrees C, IN CANADA lol.

I just found that the top section of thebypass (u shaped hose on the water pump) had one of the clamps inproperly placed (was crimping the hose), not holding it on the housing.

Put the clamp in proper placement, will see how she goes on the drive home in a couple hours.

Crossing my fingers and hoping it is nothing major.

THANKS
 

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Discussion Starter · #6 ·
It was holding a proper temp at speed, as soon as i turned the mcc dial to the red section the engine temp would drop drasticly, setting it back to blue would slowly rise the temp gauge until back at 9 o'clock position.

I find it strange that this would happen now, have owned the car for 2 winters and never a problem hopefully that hose clamp was just slowly tightening its self until proper flow could not be achieved.
 

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I had the same problem. I replaced my thermostat with an aftermarket one and still had the problem. Couldn't figure it out so I purchased an OEM one from Saab and it fixed my problem.
 

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It was holding a proper temp at speed, as soon as i turned the mcc dial to the red section the engine temp would drop drasticly, setting it back to blue would slowly rise the temp gauge until back at 9 o'clock position.

I find it strange that this would happen now, have owned the car for 2 winters and never a problem hopefully that hose clamp was just slowly tightening its self until proper flow could not be achieved.
I see similar behaviour. With the heat off, temp needle is exactly at 9 in all driving.

When I turn the heat on, and the needle drops to 8:30 or so. It drops more if driving slowly in top gear.

The funny thing is that the drop isn't all that different if I have the heat on medium-high and no fan, or if I have the heat pegged and the blower running on 3.

I wonder if the temp sensor is downstream of the heater core flow and is affected by cooler coolant coming back from the core.

If you have a scanner or openSID, you should see what temperature the ECU is seeing. My suspicion is that the temp gauge drop is cosmetic.
 

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I havent really seen much heat use yet this year, but my temp guage also has a hard time getting past a quarter of the way up on cool mornings with highway driving and the cold air blasting through the radiator. Slow, around town driving it will get up to operating temperature. I am replacing the thermostat and temp sensor with OEM ones next week.
 

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Griffin...There is a possibility that nothing is wrong and that we are being over-sensitive.
An improvement (too late now), would be a real temp gage with numbers, and not time !!
 

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Discussion Starter · #12 ·
Thanks for the replies guys.

I have owned a couple saabs and never had this happen that was why I overstressed about it.

I have been thinking is it prehaps possible that all the air was not bled out of the system (mainly the heater core causing change in temps when the heater flap is opened).

I guess I should not stress over everylittle detail but my car is my baby and I just want her to be totally healthy.

Cheers
 

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These systems self bleed. Even if it had an air lock, I can't see how turning on the heater would cause the issue you see.

Something is wrong...
 

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These systems self bleed. Even if it had an air lock, I can't see how turning on the heater would cause the issue you see.

Something is wrong...
Yep. The only device that controls water temperature is the thermostat. If he had a bad water pump it would be a heating problem. If he replaced the temp sensor for the gauge and it is still running cold it is the thermostat.
 

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Then , either the t-stat is no good or its good but mal-installed - the little bypass port must be at the top. My replacement unit has a check valve in this port, I think that its absolutely impossible to install the replacement backward.....but cheap non-OEM parts have lower quality quite often.
 

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Discussion Starter · #17 ·
Problem still persists, have ordered a genuine saab thermostat and will install when it comes in hopefully this week.

The previous one I installed was not a Stant thermo and had no bleed hole so i drilled a same sized hole as the previous one I took out of the car and installed.

Will let you know if this proper thermo fixes my problem.

Thanks again guys you really are fantastic
 
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