tdelaive

My 2002 Allroad keeps burping forever while I have the super filled reservoir elevated, cap off, and revving at 2000-3000 RPM's for 2-3 minutes. tried higher RPM's (4-6) in case of a persistent bubble but to no avail. Did this twice now, once for at least an hour, yesterday for at least 45 minutes.It gets hot at the feet inside the car at 4000 RPM when I rev it, below 1500 it starts to get cold.
There was some documentation from the last owner talking about a pinhole leak in the radiator. Is there a possibility that it's sucking air through the radiator but not leak coolant?
I can't seem to figure out where there could be a one way leak so to speak, don't seem to be losing coolant, just sucking air.
There seems to be a lot of air coming out of the cooling system even after repeated burping efforts.

4Driver4

Burping?
Nothing should "burp" once the system is bled. Did you bleed it correctly?

5v/cyl

Common problem for the AR and A6(C5) as well. Start by flushing and back flushing the heater core out to get the grime and clogs out. Then go about the proper bleeding procedure to get the air out of the core.

If that fails, then reverse the lines going to the heater core and switch the in and out around. You will then have heat.

tdelaive

I had flushed the core extensively last winter, but I guess it was time again, got some CLR and a drill pump and went to town on it, then flushed it with the garden hose, switching back and forth between flow directions, then bled with compressed air and the top hose and now I have warm air at idle, hot at around 1500RPM, I'm going to let it cool down and try to bleed again at the top hose.
Thanks guys, should be a more comfortable trip across the Rockies and back next week.
Would really like to put a bleeding nipple on that top hose, what a poor design.