[Trevor N.]

Slight emergency regarding my timeframe here, have done some searching but thought I would toss out the specific symptoms and see if anyone is familiar with them. Car is a 2000 9-3 5-spd base model.

Yesterday, responded POV to a fire department call and left my engine running with red lights on to block traffic. Noticed over a few days prior the temp gauge would dip while driving.

At the scene, I turned it off after about 20 mins. When I got back in about 30 mins. later, car wouldn't start. After I let it cool about 45 mins with the hood up, car started again. I added coolant since the reservoir tank was empty, which certainly caught my eye.

No smoke on startup except for a puff a week ago, figured it was due to the seafoam I had put in the fuel. New radiator and coolant in September after old one developed severe leak at ~140k.

Bought a thermostat on the way home today due to prior reading. Tonight I got home and saw coolant was a little bit low again. I am barely even an amateur at mechanic stuff, so I decided to see if I could burp the system before doing anything more complex.

Coolant (Dex-Cool orange) overflowed with the cap off. I replaced the cap and turned off the car, waited until coolant retreated from reservoir, and added a bit more to replace what was lost (maybe half inch below KALT mark).

I waited a bit and started it again, to see if it would have the same problem as at the fire call. Started right up, ran with the hood open a few minutes, temp gauge right in the middle.

Closed the hood, watched the temp gauge another three or four minutes, still sat in the middle. [EDIT: Fan came on and went off when I switched on A/C, but not otherwise.] Then suddenly the driver's side upper radiator hose to the motor blew violently, ripped clean in two.

No milky oil on the dipstick. I plan on installing the new t-stat and replacing the hose this weekend.

Any help or direction to an applicable thread would be much appreciated.

Thanks in advance!

 

[steve12955]

Sounds like your low speed fan circuit is faulty causing engine to run too hot. If fan only works on high speed with AC then I suspect it's the fan resistor mounted to the cooling fan. It's a common issue on older Saabs.

To test circuit and resistor, with engine and key OFF, remove low speed relay in engine compartment fuse box and using a paper clip bent into a U, jump terminals 85 and 30 where the relay mounts. If the low speed works, then circuit and resistor are OK but relay may be bad. If it doesn't work on low speed the resistor is bad.

If cooling fan only works on high speed the extra load it takes to start it up can cause the fan to shake until it gets to speed and this shaking can crack the plastic tank along the side of the radiator. It may be what caused the radiator to leak in Sept.

 

[steve12955]

Hit Send too soon...
You may also have a leaking head gasket that is pressurizing the cooling system but suspect you'd notice more smoke from the exhaust especially at start up if coolant is leaking into cylinder(s) when engine is off. And you might see coolant in the oil. At idle, do you see any bubbles in the reservoir?

 

[Trevor N.]

Ok, thanks, will test that too.

 

[Trevor N.]

No bubbles that I noticed.

 

[Kei]

Might be a good idea to replace the coolant reservoir cap with a new one as this has a pressure relief valve built into it which can cause symptoms of a blown head gasket if it's not working correctly. A friend had similar symptoms and changed his head gasket only to find the problem was still there.

 

[tomcat5]

Might be a good idea to replace the coolant reservoir cap with a new one as this has a pressure relief valve built into it which can cause symptoms of a blown head gasket if it's not working correctly. A friend had similar symptoms and changed his head gasket only to find the problem was still there.

Thread jacking here but... Do the caps go due to age, use, or something else? I don't notice any bubbles but once in a while I'll find I'm missing coolant and there's residue all over the cap. It's not always and I tried the cap from my parts car of the same year and it still did it, but less frequently. Plugs all look good, I'm not losing oil, and the fluids aren't mixing.

 

[EdT]

Thread jacking here but... Do the caps go due to age, use, or something else? I don't notice any bubbles but once in a while I'll find I'm missing coolant and there's residue all over the cap. It's not always and I tried the cap from my parts car of the same year and it still did it, but less frequently. Plugs all look good, I'm not losing oil, and the fluids aren't mixing.

The only problem I've had with one of these caps is it didn't let the system pressurize. That's a little more obvious than not limiting the pressure, and maybe a bit less dangerous.