# Heater not working



## jigaway (Jul 2, 2011)

I have worn out the site search engine on this subject and have found a bunch of good info that has already helped me. My heater core is brand new, having replaced it myself. 

However I am getting no heat in to the car. 

I have learned from searches on this thread that my blower resistor is bad since my fan only works on High. I yanked the glove box out and when the heat control on the dash face is slid over, it appears the door is opening within the heater box. (The cable is attached and moving the lever)

What else could it be?? 

Before I disconnect heater hoses and take the heater box off, which is a bugger, does any one have any ideas I can try. Could it be the heater control valve? Where is the heater control valve go?? 

thanks in advance as always,

Dan


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## Eric Animal (Oct 28, 2007)

Dan, IF you have a heater control valve, it should be under the hood, installed in one of the heater hoses that attach to the heater core.....there were a couple different systems in 1970....non-A/C, "Power Flow Ventilation",......does the unit blow air but not warm air? More info Please! Eric


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## jigaway (Jul 2, 2011)

Thanks Eric. The unit is blowing, but there is no hot air. Used to be an AC car but yanked that "like a bad ugly tooth" when we re-did the engine. 

Dan


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## Eric Animal (Oct 28, 2007)

There should be a HCV in the heater hose, under the hood....it looks like a little flying saucer. The hose goes in one end and out the other...there is also usually a vacuum fitting in it also....It sounds like you might have accidentally removed the controls ability to work, when you removed the A/C...Or the control could be Bad...or you could have an "air bound" heater core..........Run the car up to temp. Go under the hood and feel the hose going to and coming from the Heater Core....they should BOTH be very warm/hot is water is flowing thruoug the heater core......report your findings. Eric


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## jigaway (Jul 2, 2011)

Very interesting you say this. I have felt both hoses after the engine went up to temp. The (I think) inlet, going from the top back of the block in to the heater core has been burning hot, while the outlet, running out of the heater core up to the front lower block by the water pump, has been barely warm.

I'll bet something got left out??

Many thanks for any input..

Dan


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## jigaway (Jul 2, 2011)

Ok, after going back through some pictures, I think this is interesting. 

https://picasaweb.google.com/awayjig/1971GTO#5635201159970705922 

Looks like the HCV in the upper left of this picture? Right now, I have , ONLY, a hose coming from the back top of the block going in to the heater core and then from heater core to underneath the water pump. Period. The HCV should be in nmy barn with the rest of my AC that was pulled. 

should this go back on one of the lines?

Dan


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## Eric Animal (Oct 28, 2007)

Yes, BUT....if the HVC os NOT installed you would be getting maximum heat. IF the hose going in is hot and coming out is cool...the water isnt flowing thru the core....disconnect the return line and see if hot water flows through......you might be air bound. E


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## Matthew (Feb 11, 2011)

It sounds like you do not have sufficient circulation through your heater core. A heater control valve will not improve the circulation, but rather restrict it when not needed. Not saying you don't need it, but you shouldn't need it to get heat. Sounds like you have one of two problems: 1) restriction in your heater core, or 2) a bad thermostat restricting circulation through the entire system. With your system completely full of coolant, check the thermostat first. Your thermostat should open when the vehicle is at operating temp. Simply squeeze the top radiator hose to determine if your thermostat is open. If the thermostat never opens, replace the thermostat. If the thermostat is open and you still do not get circulation through the heater core it is likely a restriction at the core. You can check after the engine cools down by simply disconnecting the top hose from the engine and the bottom hose from the core and blowing through the hose. Should be no difficulty in blowing through the core.


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## jigaway (Jul 2, 2011)

Ok, this is starting to get weird, and good. The other day, I had the car out for a drive. Once I parked her, a few seconds later, the top hose coming off the radiator blew off (at the radiator). Blew coolant all over my driveway. It is a brand new 160 thermostat I put in last week. I am not home to check the items you have both mentioned. Will do when I get home. Thanks for the help.. Much appreciated. If I can get this heater licked, I'll sleep better and the car will be functioning more or less at 100%

@ Matthew, nice to see another owner in Va. I was wondering if I was the only one. I don't see any at car shows/cruise-ins.

Thanks!!

Dan


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## Matthew (Feb 11, 2011)

Dan, I think you want your thermostat around 190. Also, sounds like you lost a lot of coolant. You should take the radiator cap off, start the engine and fill the radiator. Let the engine heat up with the cap off. As the system starts to circulate, you will need to add more coolant. It may burp at you a couple times -- that is normal. Once it is generally full, put the cap back on. Then you can check for heat at the core again. Again, it may be a restriction in the core as well, but do the basics here first. 

All good over in Manassas. You live over in a beatiful part of VA. Matt


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## 1970 Lemans (Jul 25, 2009)

Sounds like an obstruction in the heater core. You said you put in a new core. These things usually have plugs of some sort that you remove when you install. Any chance one of the plugs didn't get removed? I would disconnect the outlet hose from the core and make sure it is clear (actually I would check both). If you visibly see a plug then that's the problem. If not, I would attach hoses to both ends (but neither connected to engine ) and see if you run water through with a hose (use a thin nozzle to make the connection). If you have flow, then the core isn't the problem ... if not ... well, then something is wrong with the core.

Also, in addition to setting the heater control to heat, do you have the temperature set all the way to hot ... and is that working ok?


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## jigaway (Jul 2, 2011)

I'll try blowing thru the heater core tonight. I just got off the phone with the guy who rebuilt the engine. He thinks that the water pump is probably not mving coolant through. He had said he thought it a bit odd that he didn't see coolant circulating, with the radiator cap off, when he was testing it. I also keep getting gurgling/boiling sounds at the pump. It is a brand new pump.. prob made in China! 

I'll do the prelim ideas everyone suggested, but I have a feeling the pump is going to have to come off, to check the plate clearance and see if the pump is ok itself.. 

Thanks all for the thoughts.. 

Much respect to all of you who do the ground up repairs/restorations.. Mine was a resto-lite and the few little nagging problems have driven me nuts 

Dan


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## BearGFR (Aug 25, 2008)

jigaway said:


> I'll do the prelim ideas everyone suggested, but I have a feeling the pump is going to have to come off, to check the plate clearance and see if the pump is ok itself..


At this point just from what you've said, it's enough to be very suspicious about that water pump - I'd pull it and have a look see even if you're able to get the heater going without pulling it. I've heard of them being installed with a mile of plate clearance, and in some cases even the two short tubes that seal to the back of the plate being completely left out. No bueno...

Bear


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## Matthew (Feb 11, 2011)

Hey Dan, back to Eric's point about more info... OK, so you had the engine rebuilt and then started have problems -- all related. Heater core failed under the pressure of the cooling system and you had to pull the AC to get at it. Replaced the thermostat with a 160 degree to run cooler. Top radiator hose blows off under pressure. Assume your temp warning light is coming on as well. I think you and Bear have isolated the problem. Matt


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## Eric Animal (Oct 28, 2007)

BearGFR said:


> At this point just from what you've said, it's enough to be very suspicious about that water pump - I'd pull it and have a look see even if you're able to get the heater going without pulling it. I've heard of them being installed with a mile of plate clearance, and in some cases even the two short tubes that seal to the back of the plate being completely left out. No bueno...
> 
> Bear


Boiling sounds???? Definately not good! Me thinks you have a bad waterpump, or t-stat....certianly a circulation issue......:confused...didn't know about those symptoms!! Eric


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## jigaway (Jul 2, 2011)

okey doke then.. Just in from running her thru the tests. 

1. I took the heater hose off near the water pump. Put a makeshift stopper in the hole on the water pump to prevent the coolant from running out. Blew in the hose end and heard the air/coolant running thru the hose and it blew coolant out the hole past my makeshift stopper.. 

2. Reconnected the hose. Started er up with the radiator cap off. It idled for about five mins before the coolant level started rising and falling an inch or two in the radiator. It burped a few times and a little coolant came out two or three times. The coolant continually rose and fell. The main hoses started heating up. Within a minute or two, the two main hoses were pulsating big time... I am assuming the coolant was washing thru?

A little coolant came out the overflow tube. I had filled her up really high the day before after the hose blow-off incident.

3. At this point both heater hoses were equally barely warm in temp. 

4. Took er for a five mile ride. Ran it hard. came back to the garage and opened up the hood. Heard gurgling for a moment then nothing. Popped the hood.

5. The main hose running form the top of the radiator to the top of the block was hotter than the bottom hose. 

The heater hose running from the top-back of the block to the heater core was significantly hotter than the heater hose running back to the water pump.. :confused

6. No hot air inside the car at all during idling or driving. I noticed all of my air was coming from the bottom vent that basically lays on the trans hump.
Again, the fan runs only on high. I know from archived posts, I need to replace the blower resistor.

thanks again in advance for any ideas??

Best 

Dan


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## 1970 Lemans (Jul 25, 2009)

I would be inclined to agree with BearGFR's comments regarding the water pump/setup. 

From what you have done, there appears to be no obstruction to flow within the heater core. That the return hose does not get hot indicates to me that lack of heat is not the result of an air pocket (with resultant poor heat transfer within the core) but rather no or little hot coolant flowing in.

FWIW, the vacuum valve that you mentioned is only used with an AC system, to restrict flow (and thus heating of core) when the AC is turned on. Since you removed the AC, you don't need it, and it is not the culprit. Also, I don't think a malfunctioning thermostat would affect flow to the heater core, only to the radiator through the top hose. But that seems to be OK anyway. Your controls (inside vehicle) sound like they are working properly (air should mainly come out the bottom vent above the trans hump).


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## jigaway (Jul 2, 2011)

ok, this is a little scarey. I don't think I even have a water pump plate installed in there. 

Correct me if I am wrong, but the edge of the plate should be visible along with gasket of the water pump itself?? 

I think the only reason my car hasn't blown up is because it is Winter!

Dan


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## 1970 Lemans (Jul 25, 2009)

jigaway said:


> ok, this is a little scarey. I don't think I even have a water pump plate installed in there.
> 
> Correct me if I am wrong, but the edge of the plate should be visible along with gasket of the water pump itself??
> 
> ...


That's the way it appears on mine ... water pump-gasket-plate-gasket. Sounds like you have your solution.


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## jigaway (Jul 2, 2011)

That's it. No plate in there. Holy crap! Already ordered a new stainless plate and pipes, gaskets.. I'm going in..

Thanks for the help

Dan


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## Eric Animal (Oct 28, 2007)

Gasket-plate-gasket is what you should see. if the plate is missing, the pump will stir the water, but not move it in any direction with much force!!!


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## jigaway (Jul 2, 2011)

Couple more questions since I have never yanked off the waterpump and installed one of these:

I ordered a plate set with gaskets and coolant pipes. eBay - New & used electronics, cars, apparel, collectibles, sporting goods & more at low prices

I assume the coolant sleeves fit in to the timing chain cover, then plate, then water pump?

What the heck are "Timing Cover <Align> Sleeves" and should I need those as well? (P74 in the Ames Cat. Little silver rings with a dog leg seam)

I see them listed along side of the plates and coolant sleeves/tubes.

Thanks 

Dan


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## Eric Animal (Oct 28, 2007)

Correct on the rubber inserts...you don't need the metal alignment sleeves.....Here is a pic to help you. Happy Thanksgiving, Eric :cheers


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## jigaway (Jul 2, 2011)

Many thanks Eric and all who have helped. Hope to contribute more on these boards as time goes instead of just asking questions.

Happy thanksgiving to all! :seeya:


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## BearGFR (Aug 25, 2008)

Timing cover alignment sleeves go on the two bottom corner bolts of the timing cover. They fit into the back side of the bolt holes on the cover and also into the front of the bolt holes in the front of the block. Their purpose is to center the cover so that the crank seal is centered on the crank snout. You don't need to remove the timing cover to work with the water pump like you're about to, but if the parts you're buying included these sleeves then be sure and save them in a place where you don't lose them. It's not unheard of for them to be 'forgotten' during a rebuild, and leaving them out can cause premature wear of the front crank seal.

Bear


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## Eric Animal (Oct 28, 2007)

Most welcome Dan!....eric


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## jigaway (Jul 2, 2011)

Water pump divider plate tuned, tightened and installed. Really makes a difference cooling a Pontiac 400 with one of those

Thanks again all for the advice/help. Eric and Bear, thanks for the diagram and posting that little Youtube on tweeking the plate.

Now can finally drive my baby worry free!

Dan


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## Eric Animal (Oct 28, 2007)

:cheers...good job! Enjoy.


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