Ok I'm sure I just missed something stupid here but I thought I would check to see if anyone else ever ran into this:
My xj takes forever and a day to make heat. pretty much have to wait till it's fully warmed up to get lukewarm air. never gets HOT. just warm. I already backflushed the heater core and got good flow through it. anyone have any problems with their blenddoors not shutting all the way? only other thing I can think is that the coolant mixture is a bit on the antifreeze side and less water because I dumped half a gallon of pure into it before realizing it wasn't premixed. I don't see any sort of heater valve. hoses appear to be connected right. I doubt it's the t-stat because the engine gets warmed up good. I checked both sides of the core (inlet and outlet lines) with a infared thermometer and they're running about the same as the upper hose. all I can think is a partially blocked heater core or the blend door is allowing cold air past.. any ideas before I go ripping the dash out?
also don't know if this would have anything to do with it but the head has been replaced within the last 6 months.