Coolant bleed question...

[bmx672]

So I did my coolant flange and thermostat... I bled it for a while (about 5-10min) and today it was still making a gurgling sound after driving it. Did I bleed it long enough? It was steaming the whole time through the bleeder valve when I bled it...
Thanks for any advise!

[igo4uga0586]

you loosen the bleeder screw until coolant flows from it....

[bmx672]

That's what I was wondering! Ill bleed it more! Thanks for the tip!

[MikTip]

Ya have to add coolant to tank to replace/force out air....coolant level in tank sits higher than bleeder screw....the system can be bled without driving....steam doesnt transfer heat......

With engine cold, loosen bleed screw...add coolant until coolant exits via bleed screw.

Bled my B6 like this many times...always worked good.

[bmx672]

Thanks!
I took it for a test drive and the heat was kind of goofy. I think because there's so much air in the system still! I've never had a heat problem so that's my guess...

[diagnosticator]

When filling the system with coolant, fill the tank and allow the system to fill slowly by gravity. It takes awhile and you will need to refill the tank several times. It takes about 30 to 45 minutes for the system to fill completely. After the coolant level in the tank stops falling, refill the tank then bleed the air from the bleeder screw in the metal coolant pipe. After bleeding the air from the bleeder screw, top up the tank if needed, then reinstall the tank cap, start the engine and run the engine at 2000 RPM until the rad fan runs. Next turn off the engine and let the coolant cool down to room temp, do not remove the tank cap while the coolant is hot, then top up the tank again if needed. Reinstall the cap and drive the car.

[MikTip]

^^^

[jacobsen]

This is a pressurized system. In order to bleed the this system you must add coolant to the reservoir and run the engine. The capacity is about 2.5 gallons I believe. It's over 2 gallons. So after you've run it and added the coolant wait for the system to get hot, when the temp gauge says hot it should be okay to begin bleeding, yes it can be done in neutral. Audi instructions are revving to 3k RPM for 3 minutes and bleed, do this until heat is consistent. After you rev the engine to 3 k for 3 mins go to the bleeder screw and crack it slightly. Allow the air to escape and close it. You want to bleed in very small increments, your depressurizing the system each time you open the bleeders. So don't depressurized until coolant stop. Just do a little at a time. If you bleed until coolant stops you let air in the system. You want to keep it pressurized at all times. You want to let it regain pressure before bleeding it again. It takes a while to do this. Bleed locations are the screw on the hard pipe and the top heater core hose. If it is blowing steam then your engine is too hot and boiling off the water. Add more coolant, let it run and wait, if it's still blowing steam give it some revs to help push the coolant through. Bleed in small increments and let it regain pressure, until each time you open the bleeder it flows water at good pressure.

[MikTip]

This is a pressurized system. In order to bleed the this system you must add coolant to the reservoir and run the engine. The capacity is about 2.5 gallons I believe. It's over 2 gallons. So after you've run it and added the coolant wait for the system to get hot, when the temp gauge says hot it should be okay to begin bleeding, yes it can be done in neutral. Audi instructions are revving to 3k RPM for 3 minutes and bleed, do this until heat is consistent. After you rev the engine to 3 k for 3 mins go to the bleeder screw and crack it slightly. Allow the air to escape and close it. You want to bleed in very small increments, your depressurizing the system each time you open the bleeders. So don't depressurized until coolant stop. Just do a little at a time. If you bleed until coolant stops you let air in the system. You want to keep it pressurized at all times. You want to let it regain pressure before bleeding it again. It takes a while to do this. Bleed locations are the screw on the hard pipe and the top heater core hose. If it is blowing steam then your engine is too hot and boiling off the water. Add more coolant, let it run and wait, if it's still blowing steam give it some revs to help push the coolant through. Bleed in small increments and let it regain pressure, until each time you open the bleeder it flows water at good pressure.

Very dangerious to bleed a hot and pressurized coolant system...you risk burning yourself if not properly accomplished.

For the past 10 years of owning and DIY repairing my 2004 B6 A4 I've never bled it hot...always cold, and its always bled fine.

Cold and gravity can easily bleed the system, if you have a working knowledge of the system.

Personally I would never suggest bleeding the system hot or pressurized to anyone, especially on a public forum.

[Charles.waite]

Very dangerious to bleed a hot and pressurized coolant system...you risk burning yourself if not properly accomplished.

For the past 10 years of owning and DIY repairing my 2004 B6 A4 I've never bled it hot...always cold, and its always bled fine.

Cold and gravity can easily bleed the system, if you have a working knowledge of the system.

Personally I would never suggest bleeding the system hot or pressurized to anyone, especially on a public forum.

Yea. I tried that once. Nearly sprayed boiling hot coolant all over myself. Luckily I was wearing long sleeves.

I do what Diagnosticator suggested. Just let it gravity bleed. Took me around 10 minutes total and I would estimate it was 90% full. I just toss a 1/2 gallon of premix in my trunk and check it once a day after that, and top it off where necessary. Usually only needs one top off after letting it gravity bleed.

[Timtheguru]

Opening the bleed valve with the car running will suck in air most likely. lol

[bmx672]

Thanks for all of the feedback guys! Bled it more today...
But at idle it still blows cool air:( if I run the rpms up over 2k then the air comes out hot. Not sure what the deal is now:( is this an issue with air in the system still?

[Timtheguru]

Have you bled the heater core? I didn't read through all of the tech comments here to see if they told you to do that.

The overall system is self bleeding, so after a few miles (5-100mi) it should get the air out of the heater core, otherwise a bleed of the heater core is in order.

Edit: Also your heater core may be clogged a little.. but first things first.

[bmx672]

Ill look into bleeding the heater core...
But here's a video of my second time around trying to bleed it. I ran the car up to temp then shut it off. Looks like there's still a lot of air!

http://s1116.photobucket.com/user/Bm...2C3C5.mp4.html

[Charles.waite]

Turn the heater temperature all the way up so it read HI and crack the fan speed. Then drive the car around until the heat comes back. I've never had an issue with heat not being restored when I do this...

[Timtheguru]

WTF, why are you bleeding it either 1. With the car on OR 2. with it really hot....

Bleed with the car OFF and COLD.

[Charles.waite]

Ill look into bleeding the heater core...
But here's a video of my second time around trying to bleed it. I ran the car up to temp then shut it off. Looks like there's still a lot of air!

http://s1116.photobucket.com/user/Bm...2C3C5.mp4.html

Ignore bleeding it at the upper pipe. Just drive the car for 10-20 miles (much less usually) as long as you keep your eye on the temp gauge and don't let it overheat for some reason you're not going to do any damage.

Seriously though you really shouldn't need to bleed any air out of the upper pipe. Its more or less a self bleeding system.

[customa4]

Copied from a post earlier today

There's a lot of information around here on the topic, here's some good info from OG. Click Read through that thread for a lot of good info.

[bmx672]

Thanks again! I think at that point I will just drive it and hope that it sorts itself out!

[bmx672]

Looks like ill need to do a heater core bleed. Drove the car for 17 miles and still no heat with rpms under 2500.
What I did do to cheat the system though is drive it in tiptronic to keep my rpms up to 3000... That seemed to help keep the heat on! So I might have to do that for the next day or so until I can get to the heater core bleed:(

[jacobsen]

Just use a little rag around the bleeders, it wont let air in because it's under pressure, if you bleed a little bit at a time you won't lose all the pressure, just the air. I've been bleeding this way forever and never had a burn. He's stuck in sparkle ferry air bubble zone. His heat wont work right until he gets that air out, yes there could be some sandy sediment too no doubt and perhaps bits of plastic and rubber.

[caldy315]

Looks like ill need to do a heater core bleed. Drove the car for 17 miles and still no heat with rpms under 2500.
What I did do to cheat the system though is drive it in tiptronic to keep my rpms up to 3000... That seemed to help keep the heat on! So I might have to do that for the next day or so until I can get to the heater core bleed:(

I don't know if this would qualify for Audis but it should in theory. When doing my brothers heater core in his ford truck, many that had heat at higher rpms meant it was time for a water pump because the impeller blades were worn.

[bmx672]

Okay guys I have driven the car for many miles and I still have no heat at low RPMs
I think it this point I need to bleed the heater core...
I saw a YouTube video where a guy puts compressed air through it to clean it first... Is this a good idea? Or do I run the risk of having even more air in there which I think is the source of my problem of not having heat?

[customa4]

Here ya go.
http://www.audizine.com/forum/showth...-working-again