Burp Coolant

dirk

New Member
I put a new thermastst in my 3.9 today I drainded about 4 qts out and now it will only take about 2 back. I think I got an air block. Do I loosen the plug on the bleeder tube an fill it until coolant come out. Do I run the engine while I do this. I got no heat from the heater. What is the right way to do this Thanks Dirk
 

fasterthanyou

Active Member
Yeah loosen the bleeder and fill from the radiator until coolant comes from the bleeder. Reinstall the bleeder screw.

Run the engine with the radiator cap off and a bucket under the radiator to catch the overflow.

I like to use the Lisle 24610 funnel kit to burp the cooling system as it does a good job of preventing coolant from spilling everywhere.

Run the engine to temp, once the thermostat opens the coolant should get sucked down rapidly and the upper radiator hose and heater hoses should become hot to touch. Once they are hot to touch you know you've burped the air out.

Without a funnel you'll probably make a big mess right before the thermostat opens because the coolant usually spews out like a geyser just before the thermostat opens. Probably something to do with the coolant reaching its boiling point since it's not under pressure.
 

dirk

New Member
Where would I get that funnel kit i'm in Ontario Canada. I will try to burp it tomorrow Thanksy
 

fasterthanyou

Active Member
Where would I get that funnel kit i'm in Ontario Canada. I will try to burp it tomorrow Thanksy
Most auto parts stores have them. Even wal-mart stocks them in their automotive section. It doesn't have to be that exact brand, it just happens to be the one I use. It's cheap and works great.
 

dirk

New Member
You do need to loosen the bleeder, I usually do it when the engine is idling.
Idle the engine for a while to get the thermostat to open.
Make sure the thermostat was not installed facing the wrong way, that happens occasionally.
Also, be sure your recovery tank is full, the motor will have a vacuum in the cooling system after it cools down.
That allows the system to draw coolant from the recovery tank.
Pete when u say make sure the recovery tank is full do u mean right full orjust to the hot or cold line. It stayed the same when I drained the rad. I have about 2 qts left that the rad wouldn't take should I put that in the tank Thanks
 

08'MustangDude

Profile Violation
At the top, there should be a bolt you loosen the burp the coolant:

Not sure if your 3.9 has it, but on my son's 3.8, that's where it is. I had to replace the thermostat on his,
and it overheated as well. We had to burp the air out there. You loosen it so that it wobbles in the bung,
as soon as the engine heats up. If you loosen it too much, it will pop out with the pressure. You will
see the coolant bubble out as the engine gets hot, and add coolant as needed. I found the pic and added
the caption...

The 3.9 is the same engine, so it should be there.
 

Sam36

Active Member
There's three ways that I've handled this:
1) Have the front of the car on a steep incline and fill through the radiator with the engine running.
2) Have the car level and fill through the radiator, then start the car, pull the top bleed plug and keep filling with the car running until no more bubbles come out of the bleed hole
3) Pull the radiator cap and bleed cap, fill via the bleed hole until runs out of the radiator.
 
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