Saabscene Saab Forum - Saab Technical Information Resource banner
1 - 7 of 7 Posts

·
Registered
Joined
·
14 Posts
Discussion Starter · #1 ·
I have '96 9000T. My cooling works, but heats works intermittently, mostly after the car has been running for a few minutes. Then, it goes away. I took the aquarium top off and checked the servo arm, it appears to be working i.e. it moves when I change the temperature setting. I checked for ACCII errors on the display and found none. I checked the cabin sensor fan ..it’s working. The blower fan is working as well.

However, it appears that engine is not warming up to operating temperature (based on the temperature gauge). Yesterday after driving the car and parking it for 15 minutes and then starting it up the heat worked. I verified that it was working with a infrared thermometer and it was reading correctly at both cold and hot settings. However, I noticed it takes the return hose to the radiator a long time to heat up (15 to 20 minutes) before it reaches 185F. Before that time the return hose is only 150F.
 

·
Registered
Joined
·
129 Posts
Welcome to SaabScene, elguava.

I could be wrong, but as I understand it, if the car takes too long to warm up, it's a sign of a stuck open thermostat. The thermostat should be closed until the engine heats up enough, then it should open to allow coolant to flow to the radiator for cooling. If it's stuck open, the engine will be very slow in coming up to temp.

If I'm wrong, I'm sure someone will be along soon to supply a real answer and to smack me in the head.

mike
 

·
Registered
Joined
·
2,928 Posts
Welcome indeed!

Where does the temperature gauge needle sit when you are driving along the highway?

I tend to agree with Mike that the thermostat is a likely culprit. When the thermostat opens fully, it stops flow through the heater matrix, forcing all the flow through the radiator to ensure maximum engine cooling. So if the thermostat is opening too much and too early for some reason, it will cut off the heat, but it will come back if you let things cool off for a while.

When you say "return hose to the radiator", do you mean the top hose that feeds the radiator?
 

·
Registered
Joined
·
14 Posts
Discussion Starter · #5 ·
Thanks for the reply.

(update) It appears that the thermo is working now the temp. gauge is at 8:30 (where it normally is). Though I do suspect it too! Since, this post have been collecting add. data;
-The heat only works on hi(air has temp of 110F)coming out of vents.
-The cabin sensor appears to be working (the little fan behind the grill is spinning) I also cleaned it out.
-The outside sensor is working
-The return temperature to the radiator @ operational temp is 185F (used infrared gun)
-The ACC heats only at HI and no other setting.

In summary - I suspect the:

-ACC or
-sensor or
-Thermostat

???????

Regards,

Elguava
 

·
Registered
Joined
·
2,928 Posts
Interesting! I assume that you have done a calibration check on the ACC and that it shows zero faults. Unfortunately, it is possible for the check to show zero faults even though the interior temperature sensor is faulty. If you can borrow an internal sensor to do a swap, great. If not, and your dealer won't let you try an new one for a couple of minutes, they are quite expensive, at least here in the UK they are about $75.

I know of two cars where this has happened in the last year or so.
 

·
Registered
Joined
·
14 Posts
Discussion Starter · #7 ·
Thks Mark for response;

I ordered a thermostat because I originally thought it was the thermostat, I am now leaning toward the ACC unit.

I will probably go ahead and change the thermostat since it came today.

If the thermo doesnt work, I will probably change the sensor because its cheaper (or I might just buy the ACC and sale on Ebay if not the culprit)

Wish me luck...

Will let you know how it turns out w/in a week or so (forget the sensor I am going to order the ACC [used])

Cheers 'til next week.


Yes, I checked the Acc no faults displayed.
 
1 - 7 of 7 Posts
Top