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Discussion Starter · #1 ·
Even in pretty cold weather, it doesn't take long when I'm stopped with the engine running, before my 9000 2.3 T 's temp gauge moves from the 9 o'clock position to the 10 o'clock position, and the engine fan cuts in...is this normal ? I've never seen this happen so quickly with any other car i've owned.
 

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Mark,

you might like to read this thread.

In particular the following quote by BillJ
It is the EDU, not the ECU that controls the fan. I think I might have said ECU earlier, though. So the sensor goes to the dash and the fan control comes from there.

Be aware that on cars with this arrangement, the gauge is designed to tell "white lies", just in case you should suffer any undue stress if the temperature rises under normal driving (which it will do). The gauge will stay almost rock-solid somewhere below the middle (8 o'clock on mine) under all conditions, and will only rise much above that if the system decides that, given the coolant temperature and the circumstances, there may be some cause for concern. This may be why the gauge reading bears no resemblence to the actual coolant temperature.

On our recent rolling-road session, my gauge stayed at 8 o'clock the whole time, while Gassy's earlier-style gauge quickly settled just below the red and stayed there.  [/b]
In other words, the coolant might be hotter than you think when you stop.
 

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My journey to work is only a few miles , but if i boot it near home the fan will come on about 30 secs after entering the driveway, but will only be on for about 10secs.

I also have a problem that the dealer picked saying that the gauge was reading lower than it should.
Does anyone know what might cause this or what to check for?

Skiddins
 

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Discussion Starter · #4 ·
In other words, the coolant might be hotter than you think when you stop.  [/b]
Quite the opposite, it makes me think the car is running hotter than it should.. my 9-3, my previous NG900 and classic 900 and EVERY other car I've ever owned (with the exceptions of the Beetle and Porker [air/oil cooled silly ] have ran with the coolent gauge (once warmed through) in the middle area and only after standing for quite some time would the gauge rise and trigger the fans.

But with this 9000 (its a my1992)2.3 Turbo. I pull up to traffic lights, and about 20 seconds later, the gauge rises from middle up another 30 degrees(around the 10 o'clock position)with the fan runnings.. it stays around there after that though.. then once I move off it drops after a wee while back down to the 9 o'clock (horizontal).

I don't know what BillJ is speaking about there - but is contradictory to what I'm seeing..

(I thought I'd explained what I'm experiencing clearly enough in the first post... but obviously not..)
 

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Mark,

Given the age of your car, I'm pretty certain your thermostat will be on the radiator, and the temperature readout wil be direct from the block.

The fact that the fan is cutting in suggests that your temperature gauge is reading correctly.

It sounds like it's running a little on the warm side; the fact that your fan is cutting in also implies that there is a satisfactory flow of coolant to the radiator.

So that brings us to the question of why it's running warm. If it weren't for the fact that the fan was running, I'd suggest a dodgy thermostat. You could always try changing it anyway for an 82 degree one.

Hmm... thinks it could be some sort of restriction to the flow in the system- not enough to stop water circulating, but enough to prevent proper cooling when stationary. Which I suppose could be a dodgy stat anyway. See para above
 

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One has to suspect a thermostat problem, and it's easy & cheap to replace to check.

If the engine is running hot, the thermostat may not be opening properly, only allowing a small amount of hot water to the radiator, which will be cooled quickly by the passing air. When you stop, and there is no passing air, the hotter than normal coolant will flow down the radiator until it reaches the thermoswitch, and the cooling fan will then turn on. Thus the time from stopping until the fan comes on is shorter than normal, because you do not need to wait for the whole engine and coolant to get hotter.

Hope this makes sense.

P.S. There is much debate on this topic in the thread I referenced above, as well as details of the model year changes to the cooling system controls.
 

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.. sorry to break the chain of Marks.

But with this 9000 (its a my1992)2.3 Turbo[/b]
Snap, 'cept mines a manual. My temp gauge also rises very very quickly. What was more scarey is that after 3 weeks of ownership I had to take it back because the fan wasn't cutting in. It proved to be a broken connection in the loom and the offending wire was replaced (under warranty). However, my cars had a recent head gasket yet it still appears to run unusually warm.

As Mark E stated, the thermostat is on the rad, however it is also VERY close to the turbo. Imho it's quite possible the excessive temperature readings could be caused by heat radiating from the turbo. Well, thats how I reasoned myself out of worrying about it.

Sidetracking slightly, my heater matrix is deffo shagged, it's misting up like godknows what at the moment. So thats probably not helping matters as I've got a slow coolant loss problem.
 

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My 2.3 lpt 'overheats' in exactly the same way as Mark A's and has done for the 9 months I've had it. I suspected the thermostat so relaced it with a with a 'pukka' Saab part. It didn't make the slightest difference but as I'm not losing coolant and it's been the same since I bought it I've accepted it as idiosyncratic of Saabs (particularly as my two previous 9000 2.3's (non-turbo's) behaved similarly.
 

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My 9000T used to run at 9 o clock or below only rising to about 10 o clock or slightly above when i had been in a queue of traffic for several minutes - in fact i was quite surprised how infrequently the fan used to cut in except in warm weather - efficient radiator i supposed. My current GM 900T however runs slightly above 9 o clock all the time(even cruising on motorway) and fan kicks in quite quickly when queuing even in cold weather and only runs for a short time before turning off again. Gauge only ever seems to drop below 9 o clock if i boot it for a short while and i assume the higher engine revs circulate the water more quickly - might i have a dodgy theromstat or sender unit? I have a slight oil leak on the head gasket(front nearside) and wondered about this but am not convinced that this is the problem - no water in oil etc.
 

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My 2.3 lpt 'overheats' in exactly the same way as Mark A's and has done for the 9 months I've had it.[/b]
So does my 2.3T (MY93) gets to 9 oclock quite quickly and then sits there most of the time but will then rise to 10, the fan kicks in and it drops down to 9 again... I put it down to being a FPT automatic as my 2.3 non turbo didnt do it and my 2.0 eco doesn't do it/

It also tends to do it when I'm driving at a constant speed (say on the motorway) ... so I suspect its just the thermostat/temp sensor combination and very sensitive guauges.

Steve
 
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