I had similar situation. unbolted the head drain plug and thought "crap I unbolted the wrong bolt", cause nothing came out. Had to poke in there to get it to flow it had rusted over so.
I did the vinegar, but just through the head bit with everything off. I used a pipe cleaner thing to reach what I could and flushed it all. So didn't run the diluted vinegar through the whole system. It was while I was replacing everything. That was 2013ish and my coolant is still Blue today. |