Coolant self-burping?

Johnathan · 2022-06-23T13:19:43-0400

Hi everyone,

I've recently become the custodian of a 2004 9-5 Saab (girlfriend's car lol) and just replaced a lower engine coolant hose. Is the system "self-burping"? After installing the hose, I filled the expansion tank with coolant, let the engine run for a bit, and saw air bubbles coming out of the expansion tank. Is it sufficient?

Moreover, I've been hearing water "swirling" behind the dashboard. Is it a related issue?

Thank you for your help! It's my "first" Saab, and I am trying to take good care of it.

jvanabra · 2022-06-23T13:35:55-0400

Probably still air in the system. Usually a quick drive (long enough for the thermostat to open) is sufficient to get all the air into the reservoir... let it cool down, and top it off.

bob3000 · 2022-06-23T13:41:19-0400

Johnathan said:
Thank you for your help! It's my "first" Saab, and I am trying to take good care of it.

Welcome to SC, I have had to occasionally park the car front end high to aid in "burping" but as jvanabra noted it is usually a self settling system.

Johnathan · 2022-06-23T13:55:23-0400

bob3000 said:
Welcome to SC, I have had to occasionally park the car front end high to aid in "burping" but as jvanabra noted it is usually a self settling system.

Thank you for your reply! That's my understanding; it's a self-settling system because there is no radiator cap.

Johnathan · 2022-06-23T13:57:50-0400

jvanabra said:
Probably still air in the system. Usually a quick drive (long enough for the thermostat to open) is sufficient to get all the air into the reservoir... let it cool down, and top it off.

Thank your for your reply! After adding coolant and taking the car for a drive, a "low coolant alarm" came up, so I added more, and it seems fine now.

Jeremy R. · 2022-06-23T14:39:31-0400

After changing the coolant, I always take my car for a drive and bring a gallon of pre-mixed coolant with me. Without fail, when the car's all warmed up, the expansion tank will drain into the engine or radiator, so I pull over and top it up.

EdT · 2022-06-23T17:36:31-0400

No matter how full you fill it while it's cold, as soon as the thermostat opens the coolant level drops a lot. After running for even a minute with the thermostat open, air pockets should be out of the system. Top up to the "KALT" level (at the halfway mark), screw on the cap, and check again after a good long drive, or a few lesser drives. Fine tune the level, and then if it's not leaking anywhere, the level should stay there, well, almost forever.

Finesse58 · 2022-06-24T01:16:08-0400

You can squeeze the hoses to help and things - I'm not sure if these have a valve that one can open to allow any air to escape like systems on other cars but as others have said just drive and top it off - it'll burp itself indeed. For me I've had it take a handful of drives (18+ miles each) before it fully burps. Nothing wrong with it either, so continue to check the level up to at least a week and don't be surprised if it still gets a little low by then

Jeremy R. · 2022-06-24T02:10:52-0400

There is a valve on the coolant expansion tank cap.

Finesse58 · 2022-06-24T02:20:13-0400

Jeremy R. said:
There is a valve on the coolant expansion tank cap.

That location won't effectively remove air from the system unless it's already burped its way to the tank. Usually they're in a location where they'll spray coolant if there's not air. The cap valve is just to relieve excess pressure should it build

Mimmi · 2022-06-24T03:03:54-0400

9-5 has self bleeding coolant system.

Johnathan · 2022-07-06T10:29:34-0400

Jeremy R. said:
After changing the coolant, I always take my car for a drive and bring a gallon of pre-mixed coolant with me. Without fail, when the car's all warmed up, the expansion tank will drain into the engine or radiator, so I pull over and top it up.

Thank you for your reply!

Johnathan · 2022-07-06T10:30:10-0400

Finesse58 said:
You can squeeze the hoses to help and things - I'm not sure if these have a valve that one can open to allow any air to escape like systems on other cars but as others have said just drive and top it off - it'll burp itself indeed. For me I've had it take a handful of drives (18+ miles each) before it fully burps. Nothing wrong with it either, so continue to check the level up to at least a week and don't be surprised if it still gets a little low by then

Thank you for your input!

Johnathan · 2022-07-06T10:32:22-0400

EdT said:
No matter how full you fill it while it's cold, as soon as the thermostat opens the coolant level drops a lot. After running for even a minute with the thermostat open, air pockets should be out of the system. Top up to the "KALT" level (at the halfway mark), screw on the cap, and check again after a good long drive, or a few lesser drives. Fine tune the level, and then if it's not leaking anywhere, the level should stay there, well, almost forever.

Thank you for your reply! After the first fill, I took the car for a drive and got worried when the "low coolant" alarm came on. Then, I realized that the coolant system simply needed more coolant. lol

Finesse58 · 2022-07-06T13:47:58-0400

Oh, make sure to cycle max heat on and off. You'll want the coolant bypass valve to run coolant through those lines as well so you don't get a surprise coolant level low warning when you go to use the heat

Coolant self-burping?

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