Topic: Another 'no heat' problem on '96 C.E.
in Forum: C4 Cooling and Heating Systems
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On my '96 Collectors Edition I have no heat. I checked the temp. door and it was closed. I have pulled an 01 code off the auto climate control module, so I figure the problem is in the control module or the temp. door motor. I'll mess with that later. Just to get some heat, I went ahead and accessed and opened the door manually

and brought the engine up to operating temperature but still no heat inside....still just blows out cold air thru the vents. Afterwards I checked the door to make sure the door was still open and it was. I of course closed off the access to the door while testing. Is this part in the picture I'm pointing at below a one-way valve in the heater hose, and if stuck close, could that be a cause of getting no heat?

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Duncanville, TX - USA
Joined: 3/18/2009
Posts: 2246
Vette(s): 1985 Coupe-L98/Auto,Bright Red/Carmine.
1974 Coupe-L48/4speed, Medium Red Metallic/Black Deluxe.
I'm not familiar with a "one-way check valve" in the heater hose, but there certainly should be a heater control valve there...usually vacuum operated. If what you have there in the pic is just a valve, with NO lever, or other actuator on it, then it may be what is stopping the flow of coolant thru the heater core. I'd say take that thing out and replace it with a straight nipple, and see if that solves the problem. Just remember, if you open the system, you'll loose some coolant, and you'll need to bleed it properly to get all the air out, once you refill it.
Well...ya learn sumptin new every day!! There does appear to be a "check valve" on the '92-'96 cars(LT1).

Eckler's has them for $14.99!!
http://www.ecklerscorvette.com/corvette-hot-water-control-valve-1992-1996.html
|UPDATED|11/28/2011 9:04:01 PM (AZT)|/UPDATED|

Well...ya learn sumptin new every day!! There does appear to be a "check valve" on the '92-'96 cars(LT1).

Eckler's has them for $14.99!!
http://www.ecklerscorvette.com/corvette-hot-water-control-valve-1992-1996.html
|UPDATED|11/28/2011 9:04:01 PM (AZT)|/UPDATED|
Joel Adams
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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Duncanville, TX - USA
Joined: 3/18/2009
Posts: 2246
Vette(s): 1985 Coupe-L98/Auto,Bright Red/Carmine.
1974 Coupe-L48/4speed, Medium Red Metallic/Black Deluxe.

I wonder if someone didn't install yours backwards? I guess it's possible that it has stuck closed. I would still remove it, and install a straight-thru nipple to see if you get some heat. If that fixes it, then I might buy a new valve. I wonder what the purpose of a "one way" valve is there? Must be something to do with the reverse flow of the LT1 cooling system....
Joel Adams
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
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Crystal Springs, MS - USA
Joined: 7/29/2011
Posts: 34
Vette(s): 1973 Mille Miglia Red LS5
1981 Claret Red
1982 White
1985 Silver Metallic
1988 Yellow
1993 Torch Red ZR-1
1994 Torch Red Coupe LT1
1996 Dark Purple Metallic LT4
2000 Torch Red
2001 Light Pewter
2003 Z06 Millennium Yellow
2009 Atomic Orange
My wife's '94 had the same problem a few weeks ago...the heater core was clogged up. Check both hoses to/from the heater core and see if both of them are getting hot - if not then it's blocked and no waterflow is occurring.
Take the hoses off going to the core and reverse flush it with a water hose. The gunk that blew out of there was unbelieveable!

Heater now works great, BTW.
1981 Dark Claret Metallic - SOLD
1982 White
94 Torch Red LT1
96 Dark Purple Metallic LT4
02 Black Convertible - SOLD
03 Millennium Yellow Z06
09 Atomic Orange Z51
09 Atomic Orange Z51

Last year I had heat and this year I don't. Is this check valve something I should be considering replacing?
(No evidence of the heater core leaking.)
(No evidence of the heater core leaking.)
Love my C4!
That part is just a restrictor, not a one-way valve I found out. Anyway, I still haven't solved my no-heat problem yet. I am replacing all of the rubber hoses under the hood this weekend as they are looking pretty poor and getting soft. I'll start from square one and see if I can't get this fixed. I have backflushed the heater core succesfully (I thought) but still no heat. I verified the actuator door was open to pass heat. Question: maybe even though I backflushed the heater core from the outlet hose to the inlet hose, is it possible that water is still bypassing the core itself? That would seem to make sense why I still don't have heat.
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lanoka harbor, NJ - USA
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Vette(s): 1990 L-98 white/ red/black leather interior targa top auto
1975 L48 blue/black leather interior t tops auto
i would go ahaead and replace the hoses as you were going to do. it maybe possible that a piece inside the hose came apart and is keeping the fluid from passing thru it. if you have the electronic climate control it may be the unit that is bad.
the dynamic duo

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in Forum: C4 Cooling and Heating Systems
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