A couple years ago my stepdad thought the head gaskets on my Camaro were bad so he put some of that head gasket repair sealer crap in it, turns out it was only losing water cause he didn't tighten the water pump on correctly(it also wouldn't run right because he hadn't tightened the spark plugs in all the way) and the heater hasn't been as hot ever since. I have a new t-stat for it and I was wondering if you guys know of anything good to run through it to get all the junk and crap out of it. I'm hoping the heater core isn't plugged up. Any suggestions?

 

super flush, 2 bottles. then fill it up with water start engine have the garden hose in the top and pull the hose off the block or water pump (i forget which one lol) and give a good flush, oh if your changing the t-stat take the old one out and put housing back on then do all the stuff i said.