Can anyone out there give me any info on how to get heat out of the heater. I have tried to flush the heater it seems to have good flow. the water lines to heater are hot but will only blow luke warm air. any suggestions will be helpful thanks Butch
You can check the water valve.... does it open all the way? I have a 1990 Jumbo and mine is located in the center below the dash. You can see it (a valve with a lever that the temp cable is attached to) between two hoses. On mine, the cable was mounted loosely and was flexing to much and not pushing the lever all the way. Check this first. Also remember, (i dont know where you live, and how cold it gets) but its a water cooled 3cyl. and does not produce heat like a good old Detroit V8. Hope this helps. Let me know......
Heater I tried the valve the heat comming out is a very low temp the air is blowing good no restrictions The water temp is at 185 but the air temp from the heater is at 58 and if it gets cold out side ( 30 degrees) the air temp drops to 40 Butch
Maybe one of the mode doors in the heater box is not opening (or closing) all the way,allowing full flow though the heater core? Also does yours have a recirculation lever on the heater control? Make sure its in the right position to recirculate the inside air (in the cab) not the cold outside air. Hope this helps.
Are you sure about the water temp? Sounds like you are missing the thermostat in the engine that will not let the water get hot enough. Also does it get warmer as you drive and then get cold again when you some to a stop? If so that can mean a water pump problem, or something as simple as being low on coolant.
Heater Thanks for the info. I flushed the system installed new thermostat and replaced the fan control switch. the water temp stays around 175 to 185 at idle or when running It will only get the air temp out of the heater about 10 to 15 degrees above the inlet temp the supply and return lines from the heater are hot it seems the heater will not transfer to the air side It almost seems like I have air in the heater core I tried to bleed from the return connection at the heater Butch
Did you have heat before you drained and flushed the system? If so, then you definitely have air in it...and you need to find the highest point in the system and bleed the air out.....make sure you keep the radiator as full as you can....not the overflow bottle.
Heater No I didn't have heat before that is Wye I flushed the system. Is it possible the air is bypassing the heater core thanks Butch
It may be possible that you have a plugged heater core. I can easily roast myself out of my truck, using only ram air from movement.
Butch, Did you find the problem with your heater? I just got a truck in today with the same issue. No heat. I can go drive it and it will occasionally blow some heat, but nothing consistant. I blew some air through the heater core hoses and it flowed good so I don't think the core is plugged up. I have seen problems with air before in normal engines, but normally if you run the truck with the cap off it will eventually blow it all out when the thermostat opens. Any help would be appreciated. Supposed to deliver the truck tomorrow, but have to have heat....snowing in Missouri.
Heater It is hard to get the air out of the heater do to it being higher then the fill I was told to jack up rear of truck then fill run with cap off This worked so I installed a auto air vent to solve the problem You can bleed the air with the air vent located on the intake next to the thermostat 10 mm bolt with vent hard to see remember the truck needs to be hi in the rear to get the heater lower then the fill cap hope this helps let me know butch
