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Saab 9.5 loosing coolant fluid

I have a 2003 9.5 Saab with a 3.0 liter tdi. It has 160,000 km. The coolant light came on saying that the coolant was low, I took it to the Saab garage. They said that the ducts are compressing and that the water pressure increases in the engine and comes out of the radiator cap. According to them, it will eventually (within days or months) kill the engine. Saab does not make these engines anymore. I took the car also for an oil change which they say is not worth doing. According to them, these engines have had problems like this (i.e. it is not a one off). We checked and do not see any coolant leaking from the reservoir cap but we see some coolant leaking on the garage floor. We check the oil and see no sign of coolant leaking into the oil and therefore do not think that it is a head gasket problem. We don’t fully understand what the garage is telling us, is it a common problem ? How can we treat this ?

You need to figure out where the coolant is leaking from hose, radiator, water pump thermostat, sensor, or cap. If you are seeing it on the floor you should be able to find it and fix it.

The amount that we see on the floor is nowhere near the amount that we need to add: it goes through a liter of coolant every 2 days but we only see spots on the floor. Also, we took it to a local garage and they said they could not find the leak either because it is raining a lot here and the engine was all wet.

You are loosing it every time you drive around. Can you smell a sweet smell? It could be burning on the exhaust manifold. I would drive it around and get it up to temp. Then put it in the garage and on jack stands. With a good flashlight, start looking. It could be the radiator fins. Fell around the hose ends, when cooled down. Check underneath the water pump weep hole. Another words every where. Also, if you find fluid on the floor. Jack it up, use stands and get underneath it and start looking right above the puddle.

If one of the head gaskets is leaking into a cylinder, it could be going out the exhaust as steam. No puddles and the car will build water pressure when hot. Water vapor is a normally a major product of exhaust but if liquid is coming out when the car is hot, that is most likely the problem. That is what the mechanic couldn’t look for because of the rainy weather. Get some stop-leak at the auto parts store and pour it in. If you are very lucky, it might fix the problem temporarily. Unless you really like this car, pour the goop in and start looking for a new car. Saabs have no resale value anymore so the scrap yard may be its new home. It might provide parts to keep MY 4 cyl Saab 9-5 running!

No, there is no sweet smell. I have also looked around under the car after it is hot and parked in the garage and can’t find a leak. According to the garage here, it is a well known problem with these 3.0 TDI engines, so I thought someone on-line might be able to confirm. It has been reaining here almost every day for the past weeks, so it’s hard to get a good look under the car when everything is wet. The garage had it up on a rack for an hour and said they could not find a leak either. ???

@Stupidsaab, are you sure this shop is competent?

Have they even performed a coolant pressure test?
That would be one of the first things to do, after visually inspecting the vehicle for obvious leaks.

They should perform the coolant pressure test hot AND cold. Some leaks don’t show up unless everything is cold.
They could even add some ultraviolet dye to the coolant and let it circulate. Then they would check later on with yellow glasses and a black light.

The other guys are right, though.
You may have a blown head gasket or a cracked block. That might not show up as an external leak.

We have realized now that the leak comes from the radiator cap: whenever the car gets warm, the coolant escapes from there. We drive now no more than 20 min at a time, a few times a day maximum. Can it be that the coolant lines in the engine block are getting calcified ?

Replace the cap and clean off any residue where the rubber gasket of the cap contacts the lip the radiator where it screws on. The cap can go bad and not hold pressure.

No, that’s not it. When we take the cap off, it releases air — you can tell it is holding pressure.

“you can tell it is holding pressure”

But is it holding full pressure? It might be holding 2 instead of 12.
The cap is cheap, just change it.