[stfagos]

Hi friendly Saab folk,

I recently bought a used 2007 Saab 9-3 2.0t in the USA (had a 1.9 in the UK). It runs very nicely but there are a couple of issues, which may be related. The AC one is the biggest practical issue for the moment:

AC sometimes runs at first, but very quickly stops blowing cool air when car is up to temperature. It seems erratic but it once started blowing cool again when I was stopped still (car was up to temperature). Often it doesn't though.

I replaced fuse 36 just in case, but that made no difference. The compressor is running and the clutch kicks in when the Aircon comes on. Freon reads as normal when cold (gauge didn't work when Aircon wasn't blowing cold). It may be unrelated, but the fan doesn't come on to cool the engine when I stop the car, like the one in the UK did, even though the weather here is very hot. However the temp gauge reads normal temp. It starts cool and goes to normal temp when running, so I don't think this gauge is faulty. There was a note in the last service that the radiator had a small leak (they recommended replacing the whole radiator) but I again don't know if this is related, just wanted to give as much info as possible. I can change fuses and do minor things, but not really a mechanic, just wanted your honest advice. Thank you!

 

[dspargo]

Does the outside temp sensor show an accurate reading?

 

[stfagos]

Does the outside temp sensor show an accurate reading?

It definitely seems to, yep.

 

[Nordic-Machine]

It will sometimes have a higher reading.

 

[stfagos]

It will sometimes have a higher reading.

Thanks. It doesn't have anything particularly high. It was reading about 90, which is around what it is here at present

 

[Diggs]

Stops blowing cool air or stops blowing air completely?

 

[stfagos]

Stops blowing cool air or stops blowing air completely?

Just the cool air. The blowers work fine, and the compressor/clutch are still engaged, but it just starts blowing warm air instead. I read someone saying something about a radiator fan not coming on being the reason, possibly due to some relay, but I don't know how easy a fix this is (or if this is the actual cause). Certainly the car doesn't overheat but it doesn't have that cooling sound when you turn it off.

 

[stfagos]

A garage have said the compressor is bad, as the pressure is too low on the low and too high on the high. Is this something that would make sense as to why this problem would be there? Seems too broad and basic a solution to me, but I don't know these things.

 

[stfagos]

As yet another follow up, even when I'm driving, if I briefly switch the air con off and back on again, sometimes it goes cold for a short time again. I don't know if this suggests some kind of fan issue, or actually a problem with the compressor? As I say, it's still weird to me that the engine fan doesn't stay on at all after the car turns off. Is this normal?

 

[stfagos]

Following this up yet again - the temp sensor does actually read around 10-20 degrees too high for the first minute but then goes to a normal level. There is also an intermittent fault where the front door doesn't lock with central locking, plus another fault which is that the cruise control doesn't work. Does this suggest there may just be some doggy wiring somewhere? Any clues on where to look?

 

[dspargo]

The temp sensor wiring goes to a connector above the splash shield then up to a connector under the battery box then to the A-pillar then to the BCM near your left foot. I spent a lot of time troubleshooting a bad one. The readings that you are getting seem somewhat normal to me though I haven't noticed that mine start that much higher.

 

[stfagos]

Thanks a lot, that was very clear. It was only once that it was that high - usually it is between 5 and 10 degrees (F) hotter at the very start.

I have a feeling there may be some kind of electrical issue, just due to the indications (occasional central locking issue, cruise not working, high speed radiator fan not making a sound). I'm inclined to start by tackling the radiator fan, but that's only a hunch and not necessarily particularly scientific of me. That said, I should probably take it somewhere for them to test that.

 

[stfagos]

Sorry to keep updating, but despite the temperature being normal, the fan doesn't come on when I stop the car and I can hear bubbling from the engine when I pop the hood. Does this all point to either a fan or some kind of coolant temperature sensor?

 

[CJPeterborough]

You will have codes.......... get the car read with Tech2 and then you will have something to work with.

 

[stfagos]

You will have codes.......... get the car read with Tech2 and then you will have something to work with.

Thank you for the comment. Unfortunately there weren't any codes at all (scanned by the garage), which makes things more confusing!

 

[CJPeterborough]

If they used a Tech2 all the read backs and test functions for the fans are available etc

 

[stfagos]

If they used a Tech2 all the read backs and test functions for the fans are available etc

Thanks, yeah, they didn't give me these. I should probably go somewhere to get a full and clear diagnostic. But I'm in the USA now and there that many around me with expertise that I know of.