Join Date: Jul 2009
Location: Anaheim Hills, CA
Feedback: 0 reviews
I just did an LS3 swap a couple months back and found the heater started blowing cold air in the left-most vent. Checking online came back with the general thought that this is a failing core, tear apart the dash, replace, etc....
I read, too, about a dude that used some CLR (calcium, lime, rust remover) and let it cook in his core for 30 minutes or so, flushed and had a fully functional core again.
I pulled the hoses, made a huge mess (hate doing this--barely had the garage mopped back up from the swap, damn-it!), back flushed, forward flushed (used a garden hose and blew air through--did not pressurize the core, of course). After that I filled with CLR and let it sit for 10 minutes, flushed again back and forth. I repeated this once more and got to the point that the water just looked clear and nice and no particulate matter.
Reassembled and it's been perfect!
If your core isn't leaking, give it a go. Nothing to lose. It may not really help or answer your question here, but this saved me from ripping out my dash.
2007 JKU (ex)Rubicon w/bolt-ons: LS3 / 6L80E • Synergy Long Arm 4.5" Lift • 40"s • Dana 60s • PSC Hydro • etc.