No Heat form heater 82 CJ7 4.2l I6

galaxyk5blazer

New member
I don't have any heat coming from heater. System flushed and all clear, no blockage in system. Hose from thermostat housing connected to upper heater core. Lower core connected to rear of intake manifold. Hose from water pump near pulley connected to front of intake manifold near temp switch. Hose to heater from thermostat is hot. Hose to rear intake warm. Pulled hose from front intake and have water flow out of nipple on intake and flow from hose connected to water pump. Opposing forces seem to bee restricting flow. Also running temp at radiator doesn't exceed 180 deg. Thermostat is 195 deg.
 

Never really thought about it before. After reading your post and thinking about it, I would switch your hoses at the core. The way it is now, coolant is going in the top and and straight out the bottom, The core may not ever be filling completly. If you put the incoming coolant into the bottom, the core completly fills with hot coolant before it returns to the motor. I think it may just be gravity feeding in the top and straight out the bottom not allowing the core to heat up,(no heat).
 
Flush the heater core in both directions.
Do you have a blend door? It may not be in the correct position.
 
69jeepcj is correct, the inlet of the core is on the bottom. The trapped air in the core will not allow proper coolant flow, the coolant is trickling down from the top, running across the copper and air. You are not getting the proper contact time to the full surface area of the core, equals poor heat exchange (hot in and only warm out).


As JPNinPA recommended, I would also verify that I have the correct air flow at the different points when the position of the cables are changed.
 
Thanks for all the help. Problem resolved. Thermostat wasn't working properly. Engine temp only at 160 deg. Changed thermostat to 195 deg. Then discovered heater core leak, so I replaced core. Now everything's ok.
 
Thanks for all the help. Problem resolved. Thermostat wasn't working properly. Engine temp only at 160 deg. Changed thermostat to 195 deg. Then discovered heater core leak, so I replaced core. Now everything's ok.

hopefully, while you had all that apart, you changed the blower motor to the bigger Blazer unit.. ALL the difference in the world.. holy crap, my heater will run you out ... never before have I gotten heat like this from a JEEP..
 

frhrwa, I have read about the blazer blower motors. What year blazers are they in, fullsize, downsized(s-10), newer, older. thanks and maybe a new thread should be started on this.
 
73 blazer with ac I believe is what you want an at autozone there part number is PM102 at least I think thats it , you will only need to make the hole somewhat bigger in the firewall to except the new motor everything else is the same although some recommend a bigger amp fuse to run it like a 20 or 25 amp
 
copied from jeep forum search, its the same one I put in my '84 cj-7
I just changed out my heater core and blower motor. Advance Auto had both in stock. http://www.partsamerica.com/ProductD...rtnumber=35587 The part number for the stock heater core is 399210 for $37.00. I bought the blower motor for a 1973 Chevy Blazer six cylinder part number 35587 for $27.00. The blower motor was an exact fit to the existing screws that held it in. The stock Jeep blower fan wheel bolted right on to the shaft of the new motor. I did have to make the hole in the firewall about 1/2" larger all the way around for it to fit. I just used snips to cut around the existing hole and then a die grinder to grind off any sharp edges and then used a little touchup paint. I was amazed at how the fan fit perfectly and the difference it has made. It even has the same plug on it as the Jeep. No more need to vacuum any dirt up, just turn on the fan and it will blow everything out of the Jeep! Also, There is no need to remove the dash to change either of these
 

Recently doing a heater core in my other rig, "Easy Bake"

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I found it difficult in my area in finding other than a 3/4" made in China aluminum heater core, standard size is 2" and is copper/brass. Was realted to me that one of the parts monkeys tried one of these substandard cores in his van and it was as though there was no heater at all. Your milage may vary
 
auto-zone, o'reillys, Napa, most all have the core made in Canada and/or USA... you really DON'T want the Chinese one, unless you plan on changing it again in a few months.. if you still have trouble finding it in Albany, try Eugene.. but I'm sure its there..
 
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