No heat

[opelgal33]

Today it was raining extremely hard and my windows were fogging up bad, so I turned on the heater/front defroster to try and clear up the windows.

Dust, paint chips, I think even some 30 year old lint blew out, but no heat. As stated, blower worked fine, but never warmed up.

What should I check?

Jennifer

Sorry if this is in another forum. I looked under several and did heater search, but nothing.

[72GT]

The heater core is fed by a simple valve located near the firewall, below the carb body. It's attached to 2 heater hoses and is controlled by a cable. Maybe it's stuck in the closed position? Or the control cable has disconnected or otherwise malfunctioning.
Also, my heater core was thoroughly rusted and had to be replaced. Another thing to check is heater control plate, mine was cracked and nolonger anchored the control cables properly. I had to replace this piece too.
Hope this helps!

Bob, 72 GT

[Burst]

All of 72GT's suggestions are great. I'd just add one additional, the heater core seems to "crud" up very easily on the GT. Over the years I've had mine, I've had to "blow out" the core several times as the heat would become almost non-existent. Remove the 2 hoses from the engine side of the heater core connections. Using a garden hose pushed up against one of the hoses to the heater core, turn on the water and flush it. I was amazed at the improvement, and the joy of watching a lot of accumulated crud being flushed away and out of the cooling system. I wouldn't be sure this is your no heat problem, but it could be.

[OpelMutt]

Here is a photo (I think) of the heater valve sold by OGTS installed on the fender well of a GT. As I have been told, it is a big improvement on the original. It looks much more solid, too.
I also had the usual problems. The rubber seal inside my valve is all puffed out of shape and will barely open. The biggest problem is with corrosion on the valve actuator arms which does not allow it to open smoothly. I am going to have to drill out the pivot rivet and replace it with a new one after sanding the surfaces smooth and installing a nylon washer. This should decrease the force needed to open the valve and preserve the cable and lever inside the dash.
A temporary fix, assuming the core is clean - mine was Sludge City - is to open the hood and move the lever by hand. Totally inconvenient in the rain, of course, but anything to get the hot water flowing.

Bill and the FrankenOpel
Who needs heat in Tucson? We have plenty to spare; I'll send you some! What is rain?

[opelgal33]

Bill,

Today had a friend move the knobs back and forth and noticed that the cable is not moving the valve too well. More like pushing and pulling the whole thing rather than the lever.

Opened it manually and the heat poured out. Is there a way to fix this? Could leave it open all the time?

Jennifer

[webster]

My heater valve was like that too, when I started to hook up all the hoses. I took it out, Cleaned it up and worked it open and
closed it for about 20 mins. and lubed it up it loosened up and works real well now. Just like everything, it just took some time.

Webster

[OpelMutt]

One more try on the photo upload

[OpelMutt]

Jennifer-

A while back I pulled the valve off my heater lines and flushed the heater core. Those steps are necessary and fairly easy. Sludge WILL come out, so be sure the hose is directed away from things. The valve actuator arm and bracket surfaces get corroded and generate a lot of friction where they overlap. Remove the balve and work the lever back and forth until it frees up. Unless yours is like mine where the valve lever is so badly corroded that it just won't allow opening using normal pressure from the heater control cable. I am going to ultimately replace mine with the OGTS unit featured in the photo. This is the way to go for a long-term fix and it comes with a mounting bracket for a more secure installation. Also, the rubber parts inside my valve have deteriorated to such an extent that they also are contributing to poor seal and difficult opening/closing. Inspect the rubber inside the valve with a flashlight to determine the status of yours.

Bill

[mr_udy]

It apears as though these "threads" describe the same problem I am having. No heat and my selector not (hot/cold) doesnt move past half way towards Hot. It seams to slide fine then sudden stop at 1/2 way. Anyone know if I need the valve indicated in earlier threads? I'm going to go outside to look and see if I can move it maually from the engine compartment in the mean time so I can continue to drive my "new" gt for a few more weeks (Its like 30° something here in Rochester NY!). Not really sure if I'll even find the mentioned valve. Any help would be apreiciated!

[Glenn M]

When you move the heat lever, the valve under the hood should open and close. Valve is located on passenger side of the engine compartment under the hood ...simple follow the heater hoses. Now comes the bad part...the opel lever mechanism is made of plastic and tends to break with age. Opel Source sells an aluminum version that works great and is recommended. (very pricey). Just open the valve by hand and leave it open till you get it fixed.

[bosco]

Mr. Udy,

Look on the passenger side about even with the carb over along the side of the engine compartment......you'll see two heater hoses (close together and one over the top of the other) coming out from the firewall into the engine compartment. You'll also see the cable coming out alongside one of the hoses and going to a valve. See if you can move the arm on the valve that the cable attaches to. Moving it will give you heat, moving it back will shut off the flow of hot coolant and turn off the heat. I had to un-attach the cable at the valve in order to get the valve to move as my cable is apparently frozen.

[mr_udy]

Found it last night. Apparently the cable broke off the valve. I moved the valve effortlessly and now I have heat. Now, I imagine I can get a cable from OGTS but whats involved in installation? Do I have to remove the Dash? Otherwise, I think I'll leave it as is for a while. Thanks again for evetyones help as I am totally new to OPELS!

[jlthunder]

Mr Udy.

You must drop the column(4 bolts) and remove the dash. The heater control plate does not come out with the dash. You might not have a broken heater cable. The plastic plate in the dash is probably broken(99% of them are). You will need the aluminum replacement from OGTS, but they are pricy. They can also give you a cable if you need it. It is really 2 cables in one. One controls the heater valve and flap in the heater box.

If you need to remove the heater box, then you have to remove the dash pad. If you do that, then wait until a warm day so you don't crack the dash pad.

[kwilford]

Originally Posted by mr_udy Found it last night. Apparently the cable broke off the valve.

If the cable is broken off or detached at the valve, you should be able to see the loose end, and it is fairly easily fixed. Can you see the cable end? It should look like a lawn mower throttle cable (or choke cable); a stiff inner wire with a plastic wrapped outer sheath. The end of the wire is bent like a "Z" with the vertical bar straight up and down, which then slips into the valve arm, and the sheath is attached by a little metal clip to the valve body.

But as has been mentioned, it more common for the lever control plate inside the car to be broken. The part that breaks is the flat part of the control plate that the cable sheath attaches to. I was able to repair mine by pop-riveting an aluminum plate to the remaining control plate body. To get at it, you have to remove the dash face, as described above. Then the control plate is attached to the dash pad frame with a couple little slotted flat headed bolts. Remove the bolts, and then you can determine if the plate can be repaired or has to be replaced.

HTH

[mr_udy]

Yes....I can see the cable end. Its end broke off close to the valve in the engine compartment. I imagine I am gonna have to replace the cable..... (right?). The valve itself moves freely. The other thing is the control lever only moves from cold to "mid position" and stops-cant get it over to hot. Does this describe the broken plate as people describe above? It'll have to wait 'till next year. I want to get as many miles in as I can before they start throwing salt on the roads!

[namba209]

Mr_Udy, If you have a hobby shop nearby, that has remote control boats or aircraft, you can repair your cable with a couple of wheel axle collars, a stainless steel bicycle spoke, and a "Z" wire bender. Here's a pic of the push-pull rods I use in my model racing boats for throttle and mixture control. I also use the same setup for rudder control, I've never had one come loose even turning the boats at full throttle at over 70 mph. They've been sitting for some time are are really dusty, sorry, but the GT has priority right now. HTH.

[kwilford]

If just the end of the inner wire is broken off, and not too much is missing, you might be able to just re-bend the "Z" on the end, or maybe just remove a bit (1/2 inch or so) of the outer sheath, then re-bend the end. If a lot is missing, then it won't reach the valve body, unless you shorten the hose from the valve body to the heater core to bring the valve closer. To re-bend the heater cable end, you can try to do it with two pair of needle nose pliers, by bending the off-set (it's only about 1/16 of an inch). Or you can see if a lawn-mower shop will lend you their throttle-cable end former, which is used to bend the "Z" in lawn-mower throttle cables. These are simple little plier-like tools, that have a groove that the cable sits in, and then bends the "Z" in one perfect little motion (I worked as a lawn-mower and small-engine mechanic for the summers while in University)

If the lever only moves halfway, something else is wrong with the control. Usually if the control plate is broken, the lever will move the full distance, but the cable (and hence the valve) only moves partway, because the cable sheath clamp is broken away from the control plate.

HTH

[jvandyke]

Wow, everything is here if you look.
My temp slider only goes half way too. Cable disconnected from valve (valve actually off the car, I freed it up but it seems to stiff to be usable to me, I imagine, in order for a cable to push/pull it, it need to be fairly free moving, I'll either get a replacement valve or go electric solenoid valve.

I'm trying to determine why the slider goes only half way, If my control arm is broken, I'd like to know it now so I can be ready when I tear into it all. I can't figure out why unless the old heater valve cable is stuck or the heater box one is stuck. I don't have a glove box so I can watch the cable, unfortunately this one disappears around the side.
Thoughts?
I'd think if the control arm at the slider were busted the thing would move around all over, no?

[jlthunder]

Originally Posted by jvandyke Wow, everything is here if you look. I'm trying to determine why the slider goes only half way, If my control arm is broken, I'd like to know it now so I can be ready when I tear into it all. I can't figure out why unless the old heater valve cable is stuck or the heater box one is stuck. I don't have a glove box so I can watch the cable, unfortunately this one disappears around the side. Thoughts? I'd think if the control arm at the slider were busted the thing would move around all over, no?

Remove the dash and look at the heater controls. If it is broken, you should see it there. Most are broken. Order the aluminum one from OGTS. There are other valves out there, just search the site. It has been discussed here before.

HTH

Jeff

[jvandyke]

Alright, no way around it, I'll have to tear apart before I know what I need. I HATE down time. I'd rather have what I need in hand before I dive in, but oh well. I'll start tearing it down and know for sure.

[2 Fast 4 U]

Originally Posted by Burst All of 72GT's suggestions are great. I'd just add one additional, the heater core seems to "crud" up very easily on the GT. Over the years I've had mine, I've had to "blow out" the core several times as the heat would become almost non-existent. Remove the 2 hoses from the engine side of the heater core connections. Using a garden hose pushed up against one of the hoses to the heater core, turn on the water and flush it. I was amazed at the improvement, and the joy of watching a lot of accumulated crud being flushed away and out of the cooling system. I wouldn't be sure this is your no heat problem, but it could be.

Not only the GT, but the Ascona also has that problem too , I flush the heater core every fall so I have a nice warm interior in the winter

[ronskydivepops]

The cables in mine were only moving about half way also. My dash was already apart and I found the outside metal sheathing had a slight bend in it, prohibiting it from moving freely. Bent it back a little, put some wd-40 in it, and it's been fine ever since.

[baronbors]

I ran a choke cable from under the dash to the valve since I took the panel out- works great!!

[tekenaar]

Quoted directly from the 1973 FSM: HEATER SYSTEM - GT section:

Air Inlet-Defroster Control (Upper Lever) - This control opens and closes the air inlet and heater-defroster air door which channels the air flow to either the heater outlets or defroster outlets, or to both outlets simultaneously, depending on the position of the control. Temperature Control (Lower Lever) - This lever regulates the flow of coolant through the heater core and the amount of air that can by-pass the heater core thereby increasing or decreasing the air temperature proportionate to its travel (toward ■ - warm; toward ■ - cold).