No Heat from Heater

[importdude]

Hi, Recently my 240 Completly stop blowing hot air

Before it would work and sometimes not work. Now its Always Cold.

what things so i check for?

i was told/read on fsm about the Heatercore

My Upper Hose to Heatercore is warm
and the Lower hose is cold


anyone have this problem before??

could the watercock be bad?

[projectRDM]

Water cock is bad or the valve on the firewall is stuck closed. Try moving the temp control while someone watches the valve, see if the cable is moving easily.

[g6civcx]

Or the heater core has trapped air and coolant is not circulating properly.

[toointoxicated62]

sounds like something is stuck in it, or you need to bleed your coolant system

[s13pignose]

Out of curiosity could it be related to thermostat?

[Bernie (NoVA)]

Check the coolant level in your radiator (when cold)

To bleed it elevate the front end and let the car idle until it warms up and can cycle water past the thermostat.

[alzahakar]

Does the car actually hit operating temperature?

[racepar1]

It's NOT an air bubble, I can tell you that for sure. Air gets trapped temporarily and then it works it's way out and the system works normally after that. It doesn't come and go and then stop completely. 240's are NOT known to be prone to air problems in the cooling system like that. I don't remember if the s-14's have a heater valve either and you didn't state what car or motor you have. It could be a bad heater valve or a plugged heater core or line/hose. You need to poke around more and find out exactly where the difference in temperature is.

[importdude]

s14
ka24de

car hits 170ish max
is that too cold?

even before with the same temps it gets heat

at first i thought the nismo thermostat was too cold but i recall the heater working with the nismo thermostat

[alzahakar]

S14s have electronically controlled valves for the heater core. The valve solenoid may have gone bad.

[importdude]

any idea where its located?
air mix door?

[amdnivram]

yeah mine doesn't work either but i was told that it was due to my missing thermostat. since my temp gauge doesn't work properly either.

[importdude]

I just did a quick check this mourning

it seems like my watercock is not functioning correctly

i slided the the hot/cold adjustment to cold
looked at the linkage and then full hot seems like its in the same place.

[S14DB]

Did you do this with the car running?

[importdude]

yes i have it running idleing

[importdude]

update the airmix door motor was not working

[illvialuver]

I am having the same problem and my defrost doesnt really work, I know this thread might be old but I would like to know if anyone else got this fixed?

I also have an s14, a 96 and the car will blow only cold air. do I need to replace the heater core?

[GSXRJJordan]

I am having the same problem and my defrost doesnt really work, I know this thread might be old but I would like to know if anyone else got this fixed?

I also have an s14, a 96 and the car will blow only cold air. do I need to replace the heater core?

Nope, probably the same problem the OP had - the water cock servo on teh air-mix box (big box in the middle) isn't actuating the valve... or do you even have a valve? I remember you saying your car used to be a track car, might have the coolant lines looped, not even connecting to the heater core.

[g6civcx]

Check both hoses on the firewall going to the heater core. Both should be hot.

If one is hot and the other is not, the problem is in the heater core.

If both are cold, the problem is in the engine. Either the coolant never gets hot (overcooling) or there is a clog preventing coolant from getting to the heater core.