Hey guys. Kinda new in this forum but have spent lots of time on the AW & QW 90 + B5 forums over the 10 years.
Anyway, I bought a nice looking B6 at auction a couple of weeks ago and have been slowly working on the TB/WP work. Now that everything is back together and running like a top, I'm trying to solve a "no heat" issue. I figured it had something to do with the coolant reservoir looking like a gravy dish.
After a couple of engine flushes, I set out to flush the heater core. Nothing new here, I copied ideas from several threads. Posting in here in case it might help someone else in the future.
First I took these stubborn guys off. If they haven't been moved in a while, it will take lots of pulling or a radiator hose pick.
Then attached some length of 3/4" ID hose.
I decided to first back blow the remaining water from the HC. Set the compressor regulator to 20 psi and made a night tight fit with some black tape.
Thought I'd give you a preview of some of the crap that came loose. Yikes.
I filled the core with distilled water and then blew in each direction a couple of times.
Then it was time to try out the CLR. I used the "drill pump" idea except I modified it with a Y-valve.
With one leg of the Y up in the air, I could top off the system and keep it full for better pressure.
In retrospect, it would've been easier just to have a buck with both ends of the hose in the bucket. And probably easier too. Oh well, this worked pretty well. I let it soak, then spun it in both directions, let it soak, then pulsed it.
Afterwards, I cycled a few gallons of distilled water through there to flush any remaining CLR. Blew that out with some compressed air also.
I didn't finish up until pretty late last night, so I've still got to burp the system before I know if my heating system improves. But with the amount of silt & scale that came out of there, I'll be surprised if this didn't help.