Too much cabin Heat. Please help

[Mark sP]

Hi guys, my 89 3.2 has been in my posession since November. Throught the winter she has been lovely and warm. But now that the Warmer days are approaching, I have discovered that I cannot shut off the heat from the cabin.

On a long Motorway journey I have to open the windows fully just to stop my shoes from melting. I direct the heat to the floor simply so that I don't get the hot air in my face.

Is this something that I could check/repair myself?

BTW, If I turn up the heat control between the seats it gets even hotter! With this control at zero it is simply hot. But hotter than warm. This will be unbearable in the Summer.

PS. The car is Euro spec without A/C

TIA

[Andras]

Mark, You have to get under the car, and physically move the flapper valves "open" ; they are located near the heat exchangers. Open them, so that you can see the circular "target" to be open. The "trargets" are similar to a drawn circle with an x through the diameters.

When the heat controls are "up", then that should close the targets or flaps. When the heat control is down, it should open the flappers, thus dumping the heated air before it gets to your passenger compartment.

It sounds as if something is stuck down there. You do have to crawl under the car, or have it lifted. The flapper box is towards the front of the heat exchangers, not a part of them.

[bigchillcar]

mine is a '74, but the design is probably about the same. look underneath the car...sounds like your heater box door(s) are not fully closing. look on the heat exchangers for these things...there should be a cable/spring type mechanism and a simple bypass door arrangement.
ryan

[Andras]

Careful guys,

The flapper valvs must OPEN, not close to dump the heat. Open means you can see an opening, not "solid" looking flapper box valves.

Don't forget that the fan on the motor pushes air through the heat exchangers, no matter what. When the flapper valves are "open", then that heated air is "dumped" before it gets to the cabin. If they are closed, then the heated air is routed to the cabin.

Look underneath, you'll understand when you remember that they must be "opne" to avoid heat in the cabin.

[ChrisBennet]

Mark,
Do you have automatic heat or manual? (2 red knobbed levers)?
-Chris

[Hald]

On my '77, I found that even when the valves LOOKED open, I was still giving excessive heat in the cabin. Using a long screwdriver, I had to push the flapper enough to seal it in the fully opened positioned. Apparently, heat was slipping by enough to be uncomfortable.

Upon closer examination [required after SWMBO adjusted the heat control levers... ;^) ], I found that the wires were a bit on the short side due to being bent around the locking nut. That probably happened when an over-zealous PO/wrench tightened them down without holding the nut through which the wire passes.

[dfw911]

I just fixed the same problem on my car. Turns out I just needed to give the cable a little more slack on the passenger side flapper box.

[svandamme]

driving fast with targa roof removed also has been known to help...

[limble]

Running the heater during a race is an old stock car trick.
It helps keep the engine cooler. Good thinking. Or you could move to Minnesota where you can use the heater year around.
I agree something is stuck.

[svandamme]

Originally posted by limble
Running the heater during a race is an old stock car trick.
It helps keep the engine cooler. Good thinking. Or you could move to Minnesota where you can use the heater year around.
I agree something is stuck.

on an air cooled engine , it doesn't make sense to turn your heater on during racing...

your only diverting cooling air from the cylinders, and i doubt it's going to help much if you transfer heat from your heat exchangers to your cockpit...

that's why they remove the flapper boxes, heater hoses and put block off plates on race engines...

[Jdub]

You're talking about a heat control and giving numbers so you have auto-heat. The cables and/or the flapper windows are stuck.

You need to reset the system by being sure that, at "0", the flapper windows are fully open. That said, most folks set the full on heat (presumably 10 on your control lever) by setting the 10 to the flapper windows totally closed. That's what I'd do if I were you. The logic here is that, if you set full open to 0, you cannot be sure you will have full closed at 10, and will find heat leaking out of a partially-open flapper window.

Be prepared to purchase new cables and pinch nut/bolts at the flapper boxes. The nuts esp. love to snap if they are old and tired.

Look at parts diagrams at this site and get under the car - this is pretty easy stuff to understand once you get the picture in your head. The auto-control is another thing...I am glad to have the manual dual levers.

Best of luck,
John

[Mark sP]

Wow. Thanks for all the input and advice guys. Yes I do have the Auto control not the lever type.

I will get under the car this weekend and have a fiddle with it, before ordering cables etc.

Once again, thanks for pointing me in the right direction chaps.

And as for the Targa Roof off solution, I must point out that everytime I take the roof off it starts raining!! But of course this is England!

[Andras]

Mark,

Not to highjack your thread, but we have a Miata as Paule's car, and we bought a tonneau for it. Now we know why England invented the tonneau. It is much easier to just zip it up when the rains come, not if the rains come. LOL.

BTW, getting intimate with your car (poking around under it, inside it, and inspceting it in detail) is worth it's weight in gold. Jack up the rear, take off the rear whels, and have a good look at everything. It's amazing how much "stuff" is under there, and then you'll get to know how things work, and look.

Enjoy (in the rainless days, of course)..............

[Mark sP]

LOL. Will do. I sent the Gfriend out to buy some bandaids in readyness!!

[svandamme]

And as for the Targa Roof off solution, I must point out that everytime I take the roof off it starts raining!! But of course this is England!

it's can't be much worse than the Netherlands

that's the advantage of a targa roof compared to a full convertible
you can take the roof of while it's wet, just put it behind the seats without folding it, takes about 30 seconds to remove it, and maybe a minute to put it back in place...

with a convertible, you can't take the roof down if it's wet, because it's heavy , and wet and would grow fungus because it doesn't dry properly...

[limble]

Originally posted by svandamme
on an air cooled engine , it doesn't make sense to turn your heater on during racing...

your only diverting cooling air from the cylinders, and i doubt it's going to help much if you transfer heat from your heat exchangers to your cockpit...

that's why they remove the flapper boxes, heater hoses and put block off plates on race engines...

I was just kidding!