I have a 91 dodge Caravan that does not get heat too good.. I mean it gets a little warm but thats about it and winter is here and I cant really take my kid out in the thing cause its freezing cold... I just put in a new thermostat and got the right fluids in there and filled the overflow bottle... Im told my heater core could be clogged,,, any way to get it unclogged without taking it out? I've heard about some kind of Vinegar to add and let sit and then flush with hot water and then about using a compressor to blow the clog out... Any curtain way to do either of those things??? And would they work?? Thanks my email is madk93@comcast.net thanks again for any help you can give!!

Just to be sure, are you getting good heat when defrost is selected? If yes and you get little heat in other modes then I would suspect a door actuator in the climate control unit under the dash. If you're not getting heat in defrost then yes, I'd go with a clogged core. Since you have a 91 it may have an inline valve at the firewall that shuts the coolant flow on and off as you slide the temp switch on the panel. I'd check that out if equipped.

The only time I've seen a core flushed the guy disconnected the hoses back from the firewall somehwere, kept the input hose elevated and the return hose down. He then poored water in the input hose and watched for a like amount to poor out the return hose. It only trickled indicating a clogg. He then held the return line up, poored a standard radiator flush solvent in and let it set 10 minutes. He then lowered the return line and we saw quite a bit of gunk come out. He then poored water in to finish the flush. Two more applications cured the clogg.