no heat?


  • no heat?

    So I hadn't really tried to use my climate control since I got my Z. It gets cold when I put the air on. The other night it was chilly so I tried to get some heat going. Maybe I'm just dumb and can't figure out why heat isn't coming out. I put set temp to 90 and it doesn't get warmer. There is not a direct button that illustrates heat. Is my heater just dead?
    Attached Files
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  • #2
    There could be several reasons.

    Does it blow cold air all the time or just when the fan is on?

    Bad vacuum lines/vacuum leaks which control the heating system but this mostly tends to supply hot air all the time
    watercock/heater control valve near the passenger firewall may be stuck closed
    clogged heater core
    disconnected heater hoses due to a leak in heater core.



    1988 300ZX Turbo, Shiro Special #760
    1988 300ZX Turbo Automatic (wife's car)
    1991 Hard-body 2WD

    http://zccw.org/zccw/?page_id=1215

  • #3
    Hit "defrost." It defaults to max heat. If you have cold air, something is wrong.

    Look under the hood and see if the valve on the heater lines is working. I think it defaults to hot though.

    My first 85 had deteriorated foam gaskets behind the glovebox. It was allowing the fan to bypass the heater core and suck in cold air. A little tape and cardboard worked to rig it up for winter.

    Check coolant level. Even if no overheating is occurring, the level may be low enough to keep you from getting heat.
    5.3 LSx Z31

  • #4
    i r teh noobz;348148 wrote: Look under the hood and see if the valve on the heater lines is working. I think it defaults to hot though.
    I have seen this valve zip tied shut due to leak in the heater core.



    1988 300ZX Turbo, Shiro Special #760
    1988 300ZX Turbo Automatic (wife's car)
    1991 Hard-body 2WD

    http://zccw.org/zccw/?page_id=1215

  • #5
    Yea, mine is always hot, especially when I press on the gas.

  • #6
    Maybe someone manually tied the check valve shut for the summer, open it for the winter.
    Restore it, Don't crush it. They don't make them like this anymore.

    Scott
    85 Turbo, original owner, restored
    93 NA Babied



  • #7
    I had no heat in my car as well about 2 years ago. After troubleshooting, my watercock valve was not opening because of build up of gunk.
    Though I could have cleaned it out, I just replaced it with another I had lying around.

    So check the valve itself and make sure that it can function (open/close). The best way of doing this is with a vacuum pump. Heck, just put a vacuum line on the top nipple and suck on it (and do that to your girl as well in the bed).

    If it opens and closes properly, there could be a vacuum line split somewhere with the existing lines. Start tracing vacuum lines!

  • #8
    Nice! Yeah I'll definitely check that out. LOL water cock. Sounds like describing some kind of std.

  • #9
    Where is this said water cock?

  • #10
    samshadow;348230 wrote: Nice! Yeah I'll definitely check that out. LOL water cock. Sounds like describing some kind of std.
    http://www.courtesyparts.com/kb_sear....php?keywords=[27116]+%28Z31&cPath=2317_2318_2361_2379



    1988 300ZX Turbo, Shiro Special #760
    1988 300ZX Turbo Automatic (wife's car)
    1991 Hard-body 2WD

    http://zccw.org/zccw/?page_id=1215

  • #11
    Might be best to download the FSM or buy a Haynes to locate various parts on your Z car.
    http://www.xenonz31.com/reference.html

  • #12
    Filipe;348248 wrote: Where is this said water cock?
    Its on the firewall behind the passenger side head. Looks like this although analog climate controls do not have the electric sensor attached. This one is for a automatic climate control.






    1988 300ZX Turbo, Shiro Special #760
    1988 300ZX Turbo Automatic (wife's car)
    1991 Hard-body 2WD

    http://zccw.org/zccw/?page_id=1215

  • #14
    So this is a super old thread but a search found it, my 84' has no heat! I replaced the heater core once before and there is no coolant leaking at all. I have a good Z mechanic but he's too far away to help me, so I need to take to a local guy. I checked coolant level and it s completely full. What parts should i buy to get started?