Hello Scotty !! Thanks for doing what you do ! I have an 1988 Cadillac Fleetwood Brougham with 111208 miles on it. I inherited from my Aunt and it was garage kept and it runs like a pearl. My question/problem is that while I drive it my windshield get foggy in the middle and I don’t get any heat. I’ve been poking around trying to figure this problem out. A lot of sites are saying that my heater core may be clogged and I should flush it out. Couple of guys that have had the same problem have reversed the hoses from the core, I’m no mechanic and before I mess around with any hoses, I would like some of your wisdom on this situation please. I’ve also checked the antifreeze and it’s topped and no leaks. Thanks for your help and please keep on doing what you do !!!
Yeah, sure sounds clogged. My suggestion is to warm the car up, wrap your hands around both hoses and see if they both feel warm. If the return is noticeably cooler then look for a heater valve at the firewall or rear of engine. Try moving it on/off by hand. If it doesn't move (common problem as they age) it's probably rusty - if in closed position, try penetrant and let it set, then try forcing it to the open position. However, if the valve is okay then go ahead and try reversing hoses. <shrug> Lot less hassle than replacing core.
@warfrost
I have issue with reversing hoses...if it works you have unclogged the core but where do you think that clog material went? A disconnect and proper flush would be better. I think that car has a mechanical diverter valve and yea, the first place I'd check.
Yes, you're right - that's the correct way. My brain was on a short-cut track to get some heat right quick since it seemed like he was in a cold, snowy (?) situation. My bad.
You might have luck adding an electric fan to increase air flow.
