Saab 9-3 Coolant leak

My Saab 9-3 gushes out coolant when I park it.

Doesn’t seem to have any dribbly little leaks either when it is running or parked (but I’m not very observant). Doesn’t overheat.

Dashboard says “Fill coolant”. The reservoir is empty. I fill it to the “cold” line. I drive it till it warms up, and then park it. Coolant gushes out of the top of the reservoir. Repeat cycle.

Any insight greatly appreciated.

Year and mileage of your Saab, please. Have you ever had the coolant, thermostat, or radiator cap replaced?

You say, “Doesn’t overheat,” but gushing coolant is a classic sign of overheating. It gushes out because it’s too hot. It’s boiling, actually, which it shouldn’t do.

Refilling the reservoir is not enough. You must fill the radiator, too. Do this when the radiator is cold. Open the cap, fill completely with coolant, then fill the reservoir to the cold line. You may also have to bleed trapped air from the cooling system.

That’s the first step.

Then you have to determine whether or not the engine is overheating while it operates, and whether or not the thermostat and cooling fan(s) are working.

With the cooling system full, start the engine and let it idle. It should come up to normal operating temperature within a few minutes, at which point the thermostat will open (we hope) and allow coolant to circulate through the radiator.

As the coolant in the radiator warms up the cooling fan(s) should start to cycle on and off to maintain the correct temperature in the radiator.

If all is working correctly the engine should idle indefinitely without overheating.

I had this happen on a 1993 Oldmobile 88 that I owned. I found that the hose that connects the reservoir tank to the radiator would collapse. When the engine cools, the volume of coolant in the radiator decreases and a partial vacuum is created. This sucks the coolant from the reservoir tank. In my case, as the coolant volume expanded the reservoir would fill up. However, the hose would collapse as the radiator cooled and the coolant would not return to the radiator. A couple of dollars for a length of hose and ten minutes of work cured the problem.

This might not be the cause of your problem, but check it out. The repair is cheap.

Thank you both for your prompt replies and suggestions.

It is a 1999 with 132,000 miles.
It really seems not to be overheating: the fan runs, the temperature gauge on the dash stays right at the normal operating temperature (a little below the middle between L and H), and the radiator never gets above 170F (according to an $8 infrared thermometer from Harbor Freight “Not for medical use”).

It looks like a collapsing hose may be the culprit. The coolant return hose (from the reservoir to the radiator) is less than an inch in diameter, soft and flexible. The plastic clip that held it was broken, and the hose was sagging into the engine compartment and probably bending in ways that it was not intended.

I put it back to its original route, and secured it with zipties. Too early to declare victory, but no symptoms so far for a day and a half.

If it works, that will be a two cent repair. Thanks again to both of you for your help.

Two cent repairs are the best kind. Good luck.