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no heat from heater by maybenot
Started on: 08-14-2013 07:45 AM
Replies: 13 (404 views)
Last post by: olejoedad on 08-17-2013 09:22 AM
maybenot
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Report this Post08-14-2013 07:45 AM Click Here to See the Profile for maybenotClick Here to Email maybenotSend a Private Message to maybenotEdit/Delete MessageReply w/QuoteDirect Link to This Post
hi,
i was searching for "no heat" posts and found diagram for heating system. i just assumed my heater core was not working. the vents blow all levels, just not hot air. should/how to check other items like control valve,etc. or would it be leaking antifreeze? 85 gt/auto
thanks.

[This message has been edited by maybenot (edited 08-14-2013).]

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olejoedad
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Report this Post08-14-2013 08:05 AM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
The temp lever on the HVAC control is attached to a cable that moves the blend door in the HVAC housing. If the lever moves freely (it should have some resistance), the cable may not be attached at one end.
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maybenot
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Report this Post08-14-2013 08:09 AM Click Here to See the Profile for maybenotClick Here to Email maybenotSend a Private Message to maybenotEdit/Delete MessageReply w/QuoteDirect Link to This Post
i feel some resistance, not freeplay at all. and i hear something when sliding it. with no leaks, i was just wondering are there other things to check. i thought if a core was bad, it leaked, otherwise it had hot water flowing through it and the blower motor just blew that heat into vents.
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olejoedad
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Report this Post08-14-2013 08:24 AM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
The heater core may be plugged. No water flow = no heat.
The heater core is fed from the large nipple on the thermostat neck and returns to the water pump housing via the 5/8" hose attached to the pipe (about the 10 o'clock position when viewed from the face of the engine.
The coolant is routed to and from the heater core via under car tubing the runs along the passeenger side of the fuel tank. Check for damage on the undercar piping.
Do you have a thermostat in the car?
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Boostdreamer
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Report this Post08-14-2013 08:51 AM Click Here to See the Profile for BoostdreamerClick Here to Email BoostdreamerSend a Private Message to BoostdreamerEdit/Delete MessageReply w/QuoteDirect Link to This Post
Is this car new to you? Has the heater worked for you in the past?

My third Fiero didn't have heat. What I found was the previous owner bypassed the heater core because it leaked. He used rubber hose to connect the in and out lines under the car, directly below the heater core area. I changed the heater core then removed the bypass hose and reconnected the hoses as they should be.

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JohnWPB
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Report this Post08-14-2013 12:50 PM Click Here to See the Profile for JohnWPBClick Here to visit JohnWPB's HomePageSend a Private Message to JohnWPBEdit/Delete MessageReply w/QuoteDirect Link to This Post
Make sure the coolant system is filled correctly. If you have an air pocket, you will get no water flow. This means no heat, as well as overheating the engine. The temp gauge can also read incorrectly if there is no water flow. Small chance this is the problem if you drive it often, but if its parked and you are working on it, its worth noting.
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maybenot
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Report this Post08-14-2013 06:51 PM Click Here to See the Profile for maybenotClick Here to Email maybenotSend a Private Message to maybenotEdit/Delete MessageReply w/QuoteDirect Link to This Post
hi guys,
yes the car is new to me and the heat never worked since i have had it.
i have checked the lines running under the car and they are perfectly round not crushed/pinched, or nicked.
the hoses are not bypassed and i have a new thermostat as well as all new caps. i was having overheating issues when i first got it, and thanks to the forum, replaced those as well as all sensors and properly filled/burped system.
it has run perfect ever since. except no heat.
how do you check for clogged heater core? if it was clogged, wouldnt that effect something downstream?
i am not adverse to replacing the heater core, its relatively inexpensive. its just like i said in the beginning, i didnt know if the heater control valve or vacuum hoses could be bad or checked first. no sense replacing what isnt broke.
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olejoedad
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Report this Post08-15-2013 07:43 AM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
No heater control valve. Heater core circuit circulates whenever engine is running.

Do you have good airflow out of the vents with HVAC fan on?
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maybenot
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Report this Post08-15-2013 09:30 PM Click Here to See the Profile for maybenotClick Here to Email maybenotSend a Private Message to maybenotEdit/Delete MessageReply w/QuoteDirect Link to This Post
yes the speed control works like it should varying flow. so i guess its the core going to be replaced.
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Boostdreamer
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Report this Post08-15-2013 10:12 PM Click Here to See the Profile for BoostdreamerClick Here to Email BoostdreamerSend a Private Message to BoostdreamerEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by maybenot:

i guess its the core going to be replaced.



The only thing that can be "wrong" with the heater core is that it leaks or the fins that allow air to flow through it are clogged up with dirt, hair, leaves and junk. If it ain't leaking, at most all it needs is to be cleaned. Before going through all that, detatch the two hoses and try to force water through it with a water hose. If you have good flow, the worst thing it could be is dirty on the outside.

It is also possible to have a clogged hose where it attaches to the engine block. I've seen pics of that situation here also. So don't buy new parts yet.

Also, just to be 100% clear, the heater hose goes down the MIDDLE of the car. We are NOT talking about the metal tubes that go down the SIDES of the car.


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[This message has been edited by Boostdreamer (edited 08-15-2013).]

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maybenot
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Report this Post08-15-2013 10:40 PM Click Here to See the Profile for maybenotClick Here to Email maybenotSend a Private Message to maybenotEdit/Delete MessageReply w/QuoteDirect Link to This Post
ok thats good to hear about the core. i will check the flow disconnected this weekend and then check the underside. i thought it was the pipes under doors. i didnt know there was one down the middle. excellent catch on my misunderstanding.
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olejoedad
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Report this Post08-16-2013 06:54 AM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by olejoedad:

The heater core may be plugged. No water flow = no heat.

The coolant is routed to and from the heater core via under car tubing the runs along the passenger side of the fuel tank.


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maybenot
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Report this Post08-16-2013 07:58 PM Click Here to See the Profile for maybenotClick Here to Email maybenotSend a Private Message to maybenotEdit/Delete MessageReply w/QuoteDirect Link to This Post
olejoedad,
i meant no disrespect. i stated that i completely misunderstood. actually i just read too fast as i thought i knew what you were going to say about the coolant lines running under the car to front. i even read the part about passenger side of fuel tank but took it to mean that sides coolant line.
my apologies too you and thank you for the original help. some people(me) just need to slow down and accept the help they are given.
thank you again
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olejoedad
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Report this Post08-17-2013 09:22 AM Click Here to See the Profile for olejoedadClick Here to Email olejoedadSend a Private Message to olejoedadEdit/Delete MessageReply w/QuoteDirect Link to This Post
No disrespect taken, really. I see alot of people on here that dont read with understanding the first time.

Dont worry about it.

Besides, I like that emoticon....
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