Daleford

I have searched but most of the write ups on the heater core replacement are for pre 91s. Mine is a 93 and I believe somewhat different dash. Anybody have a link to a 93 specific procedure?

DWC4

Been through this twice with my 92 now with 165k miles, first time I had my favorite garage do replacement, it was about $600?? and they told me to never, ever come back.
That gave way again a couple months back and as I'd done to stave off a head gasket leak (water dripping out), I used alumaseal. Don't get the whole debate here started on this BUT, its used by pro mechanics in new engines and old, and SCREW what anybody here says, it solved the head gasket leak permanently last summer. So when my core blew yet again (yes, coolant on the passenger floor, steam out the defroster...) I tried it. Use 2 packages right in the coolant can near the firewall (don't put in the reservoir), it may hold it for 2-3 weeks at best. I've done it a few times now while stalling over selling, fixing myself. Now instead I'm going to keep it and do the bypass and logged in for exact info on hose sizes. You bypass the core with the inlet/outlet hose going direct into each other; no heat but I"m told it makes the AC really kick *** in the summer (not sure why...). If you do tear into yourself, good luck, sounds like absolute misery to me. Alumaseal works but only temporarily and yes, could have other ramifications down the line I'm sure but I've run mine thousands of miles and it's had many of these little packs put in it with no, zero, nada other problems to date. So there.

a454corvette

Because almost every GM car is a reheat system....air flows through the evap core, then the heater core. Even with the water shutoff valve, there is some residual heat carried through the core. Turns cold air to cool air.

DWC4

I used alumaseal but for heater core it is only temporary, bad idea. Check this thread, all you need to know about the bypass process. 2 hose clamps, a piece of pipe or pvc, maybe 30 minutes labor followed by a burp and it's done. I'm doing it tonight.

thread is: Heater core bypass problem mbfan72

patricksmithahhh

i bypassed mine easy two hoses that go through firewall connect em wuth a U fitting dont need no heat im in vegas haha

DWC4

getting those damn hoses off is sh&$##T. It's those pincer type clamps, fine, got one free but can't get the hose to pull off, hate to cut it, no turning back then plus might need every inch to turn them to face and connect. Argh.