[STEELCITYFIREBIRD]

I have a 2002 Volkswagen Passat with a 2.8 V6 engine. I can’t get the air out of the cooling system,Specifically the heater core. I know about the hole in the heater hose that you let air out from but for some reason I can’t get all the air out. Cooling system is spotless, I have no idea how the flow works in this system so I don’t know how to force flow through the heater core to remove air. I’ve search the net And tried all kinds of different stuff. Nothing has worked.I don’t know if there’s any other bleeders anywhere but I’m tired of going out to my car and it being freezing in the morning ...even after I heated up. When the car is in motion/ rpms up I do get coolant flow to the heater core and have very good heat. The heater core is the highest point in the cooling system.
Help?

[PunchT37]

Jack the front of the car up to get the radiator or the fill cap at the highest point. Worth a try.

[Tom Vaught]

I have done the same but with car ramps and as was said that seemed to work for getting the air out of the heater core on some Pontiacs.
Course if you had a two post lift it was even easier at the Pontiac Dealership.

Tom V.

[TedRamAirII]

Did you verify flow through the core? VW is famous for plugged heater cores, no matter how clean the coolant is.

[Sirrotica]

Making the radiator fill point the highest point of the system, most times will get the air out of a cooling system. It's the method I've used often after a refill of the system. Running the engine to force the water to push the air to the radiator while elevated I would think would work.

Another thought would be to use a ball valve teed into the heater hose as a bleeder point at the heater core connection. I have never tried it, just brain storming making a bleed point

[STEELCITYFIREBIRD]

All of you are on the same line of logic I’m on.

I tried yesterday, for about 2 hours total. My driveway is Very steep. I had the car backed up “on the banking.” Unbolted, Raised and suspended the expansion tank above the heater core( what I read unofficially online as proper procedure).
Their has to be something procedural I’m not doing, but I can’t find a good, concise source for the procedure.
I’ve tried it with cap on and off expansion tank, idle,increased rpm and high RPM. I lost coolant from expansion tank when thermostat opened and cap was off, high rpm, that high rpm was required to get enough heat in it to open stat. And increase flow.
Car runs on the stat and cooling system is very efficient,electric fan rarely if everver runs unless your turn it real hard to build heat while stationary.

I flushed core both directions, with garden hose attached directly, little to zero restriction, no sediment or discoloration. Rad is less than a year old.
When driving down the road I have 120*+ from the vents.

Trudging around VW forums, but not finding a definitive procedure.

There is a small hole in one of the heAter hoses that allows you to slide hose back while still connected and purge air out, just seems I can’t get it all out. Like I need to force flow thru core to get all air out. Pinch a hose somewhere? Purge When stat opens?

I can fix Or figure out anything......except this. My patience for time spent is spent.

[STEELCITYFIREBIRD]

Seeping heater core, in an area between cowl and firewall, tube snapped off in another attempt to bleed air.....another project.

[Schurkey]

Originally Posted by STEELCITYFIREBIRD

When driving down the road I have 120*+ from the vents.

Yeah, I'd be peeved at lack-of-heat, too. If my heater was that cold, I'd suspect a failed thermostat.

My heaters typically run 160-170-ish. Depends some on inlet air temperature, and of course on thermostat rating.

If this were in MY driveway, I'd have an excuse to buy one of those vacuum-refilling cooling system tools. (Airlift or similar product.)

https://www.uview.com/index.cfm?dsp=...productid=5120

https://www.youtube.com/watch?v=mdFxiz8skaQ

The other hateful alternative is that you've got a failed head gasket or cracked casting that's putting a steady stream of combustion gasses into the cooling system.