1980 datsun 310gx

[dat428]

i have a 1980 datsun 310 gx hatchback since june 2010 this winter i tried to use the heat and will not blow hot air. replace the thermostat, clean the core and still no heat. if some one can provide some in put or comments about it will be great.

all connectors are in place and the blower works. all air doors close and open .

[breadbox]

Does it have a cable activated blend door?

How bad was it when you cleaned it out?

[Encryptshun]

Did you flush the lines too or just the core?

[dat428]

the complete cooling system was clean and flush all cbles are in place
i notice the system has a termistor

it pass the resistance test
thank you for the interest dan

[Encryptshun]

What's the temp differential between the inlet and outlet sides of the core?

[dat428]

well i dont now any sugestion? or temp range

[Encryptshun]

Well, it's more about the differential and the flow rate. If the outlet temp is more than 20 degrees F less than the inlet temp after letting the warm vehicle run with the heater on, you probably have a restriction in the core. Ditto if you disconnect the return line (outlet, which runs from the core to the water pump -- be careful doing this as the pressure can be quite high) and you don't see much fluid coming through, you have a restriction.

Based on your description, I would say the problem is definitely the core. Do you notice a funny smell in the cabin when the heater is running? Do you see some greasy fogging at the bottom of the windshield where it meets the dash?

[dat428]

no the core was taken out and flush with acid no restrictions . no smell , it just dont blow hot air, the temp gage is normal, the car dont overheat , i can the see the the water rising and circulating whitout the radiador cap on so the thermostat is working also. thank again for the help dan