I have a high mileage '88 pickup. The heater valve works when the levers move, and both the input and output heater hoses get hot when the valve is open, but the heater puts out no heat. Yesterday I removed both hoses and gently blew air through the core. Air passed freely and coolant came out. I hooked everything up, refilled and burped the system and made sure both hoses had water in them. Still no hot air in the cab. Is it possible that no air is passing through the heater core? Any suggestions?

Thanks!!

 

Got it fixed...when they say "Pack a lunch" for this one they are not kidding! Pulled the whole dash apart and removed the heater core. I found all sorts of leaves and what looked like bits of carpet in the heater core housing. maybe a rat's nest?? Anyway, it's mostly back together and i have hot air now.

 

Glad you got it fixed, bro ... Sorry i could'nt help at first ... When it comes to figuring stuff out like that, i'm no good at it and end up bringing it to my mechanic ... LOL ...