other Hot Cabin Looking For Heater Valve Bypass Ideas

[mrgesq]

So I got my 76 out today for a long ride in the nice 80 degree weather.  After about 15 minutes I start getting really hot and remember that the heater valve must be shot because I have hot air blasting into the cabin from the heater.  The valve slide is set to cold and the wire at the valve has been adjusted and the fan is off. The valve must leak or is  shot.  Given the price of a new valve and the hassle to install and the  fact the I only drive the car in the warm months, what have other folks done to fix this issue?  Bypass the core with a section of heater hose?  Add an in-line ball valve to the supply side hose?  Clamp the line with a vise grip?  Anything but buy the new valve and do the contortions to replace it?

 

Creativity counts.  Thanks much.

 

 

 

 

[Rocan]

your cable might not be hooked up properly. Pop the hood and from the passenger side look at the hose that enters the heater core through the firewall. The valve is there. Close it manually and see if it changes anything. If it doesn't, then you can disconnect the two hoses from the heater core and simply run a straight piece of brass pipe with two elbows on it into it. Remember to burp your system after. 

[Preyupy]

In hot weather do not bypass the heater core, the inline ball valve is the best solution but you can also pull both hoses and plug them.

If you bypass the heater you will be running hot water from the back of the head straight back to the inlet of the water pump, thus circulating water through the engine without having it go through the radiator.

[Simeon]

In hot weather do not bypass the heater core, the inline ball valve is the best solution but you can also pull both hoses and plug them.

the back of the head straight back to the inlet of the water pump, thus circulating water through the engine without having it go through the radiator.

That is good to know (and makes sense when you say it). Thanks

Edited July 4, 2013 by Simeon

[Rocan]

In hot weather do not bypass the heater core, the inline ball valve is the best solution but you can also pull both hoses and plug them.

If you bypass the heater you will be running hot water from the back of the head straight back to the inlet of the water pump, thus circulating water through the engine without having it go through the radiator.

Woah! good to know. 

[JerryC]

I disconnected and plugged the heater hoses separately on my daily driver for several months one summer. No ill effects were noticed, until it started to get cold outside (then I got cold too). I plugged each hose with the head of an allen head screw and a hose clamp. 

 

 

[73Inka]

call Steve Blunt he sells heater valve repair kits. They are easy to install without taking the valve out of your car,

[Buckeye]

I believe in keeping these car as original as possible.

http://www.bmw2002faq.com/topic/138918-late-heater-valve-repair-kits/?hl=heater+valve#entry927154

[Mike Self]

FYI

Later 2002s have a small hole in the heater valve body that allows a small coolant circulation through the heater core regardless of heater control position.   It shouldn't cause the heater air to run hot, but will make a small difference in air temp even when the heater is set to cold.  But it will make a difference.

 

Before rebuilding, replacing or bypassing your old heater valve, make sure it's functioning properly. 

1.  Have someone move the control lever inside while you observe the valve lever to make sure it moves. 

2.  If you or a PO have had the valve out, make sure it was reconnected properly.  It's easy to reinstall so that the lever on the valve is backwards, and cold setting is hot and vice versa

3.  Those later valves have a plastic valve (the part that opens and closes the water flow).  The little nub that the lever (at the valve) bolts to can get rounded off or work loose, so that while the valve control lever moves, the valve itself doesn't.  If the first two checks don't work out, you'll have to pull the valve to check this.

 

Just hope it isn't a broken control cable!  That means pulling the heater to replace...

 

cheers

mike

[jgerock]

Adding to Mike's post ^, here is a picture of the valve in my 73. Notice the channel in the valve "spool".  I believe that is what allows water to circulate thru the heater core when the valve is in the off position.

 

As far as bypassing the heater core, I recommend against this practice.  When the engine temperature starts creeping up in hot traffic conditions (especially those of us who retain the engine-driven fan), you can turn on the heat and fan to reduce the coolant temperature.   

 

You can turn off the heater valve (cold position) but leave the fresh air flap open (heat not defrost) to get forced ventilation while driving. In my car, the air entering the cowl spins the fan, increasing the airflow and helps keep the fan "exercised". 

[TobyB]

the bleeder's actually mostly for air, so you don't get a pocket of air built up in the back of the head.

 

t

[uai]

Get one of the cheap older style valves with the brass insert and a new seal for it.

They last forever and when your hoses are not too hardened you can get them tight although the old valve has a smaller diameter.

Cheers

 

Uli

[mfbanres]

I have a valve in great condition I'll let go for a reasonable offer.

Let me know.

 

Michael

[austinmf]

Home Depot sells a ball valve that you can hose clamp in. Add it in front of the heater valve. Buy a spare hose when you want to go back to stock.

[mrgesq]

Thanks for all of the posts and suggestions. I ended up adding an in line ball valve. A 1 inch pex valve fits the hose perfectly. I painted it black and removed the handle so you can barely see it at all. I'll keep the handle in the trunk and open the valve when needed. Whole thing cost about $10 and half hour to install. First time I've had cool air flow inside the car in a long time.