Ok so I went for an oil change at a local pep boys. I've been going there for a while. They usually do a great job and most of the time every thing is cool (i.e they have the right filter, they've never broken my oil drain plug, no problems.) but this past time some dumb slapnut topped off my coolant with the Gm Dexcool stuff. What I had in there before was your average green stuff.
I already know about the hazards of mixing the two so please don't go into that I also know all about the cavitation the precipation of the sillicates and all of that.
I've read all of those threads.
I Planning picking up the BMW approved coolant and switching it out.
I also know how to drain the coolant.
My question is: Can I run fresh water into my cooling system and circulate it through after I've drained the old coolant to make sure all of that crap is out of there before I put in the new BMW coolant? I'm planning on adding the water wetter also.