heater answers??
 

Okay I give up. I have read prev. post on heater problems and have found out about the vacum servo thing, mine is bad. anyway i unhooked the arm that lets the water flow and the heater works now, but ive noticed that the heat works with my rpms. more rpms more heat anybody heard of this or know why? It sucks cause it been really getting cold in the mornings. Oh one more thing ths trsm reallly dosent say much about the heater.

yea i just got a new heater control valve and mine is sorta the same way. i heat up my car in the morning and its kinda warm on full blast. then when i start driving the heat really kicks in. i was actually going to start a thread about this haha. glad someone else has this issue (if it is one) as well. plus i heard that our heaters in our cars are crummy

im glad but not glad that im not the only one, but I was told that it could be thermostat or blades on my water pump might be worn out. I look into it and see what i can do hopefully this helps

I'm in the same boat, except i replaced that vacuum valve on the passengers firewall also... only mine still doesn't work. I can hear the motors moving in the fire wall but no heat. Is there a seperate fan that blows in conjunction with the main ventilation fan to push heat into the mix? Something is still jacked.

no heat!
 

1987 mk3 auto - heater not working- the vsv was not opening but if you join the yellow/black wire to earth the solenoid works and the vacuum opens the valve - but although both pipes get warm still no heat. The fan works OK. Problem is the temperature slide on the control panel, when this is moved forward should hear electric motor running mine doesn't. Where is this motor it must operate a flap to direct air thro' the heater matrix at the same time it must send power to open the VSV. Is it likely the slide in the contol panel is broken or is there a relay somewhere? Desperate v cold!!
(now fixed see later reply)

Well, a couple of things.

1) idle at 600-700rpm, I noticed (looking into the radiator) that the coolant does not flow good. At 800rpm, it was flowing good. So the stock water pump is underpowered at idle. Thus, heater works better while driving.

2) 195* thermostat is factory original. I run it in winter, then run 180* in summer. 15* hotter water makes better heater.

3) air trapped in heater core will not allow good heat. Go here and read.
http://www.supras.com/06/techcenter/...1d623e387fef29

4) if VSV is not working, just remove the vacuum line from engine side and put it on the water valve. This will open it and allow water to flow thru core. The valve is normally open anyway, and only closes when a/c temp is set to coldest position. Valve bad=replace or by-pass it.

5) flaps/doors inside can cause some airflow problems, but....the air that goes thru the heater core is controlled by only 1 door. If it is sending air thru the core, then wherever its coming out (defrost, vent, floor) it should be hot. So if all of the above #'d items are working, then there is a chance that the air if not going thru the core. This problem is hard to work on, as you will need to get into the dash.

http://www.supras.com/06/techcenter/display.php?QID=59

What is the VSV?

It is the Vacuum Switching Valve. The TSRM does not cover the heater (that I can find) so here is a picture of another one.
http://www.cygnusx1.net/supra/librar.../ec/EC_15.html

It is located next to the heater water valve, and always feeds vacuum to the water valve...except when the controls are set to 65*, for max a/c cooling. That's why you don't really need the vsv. Just bypass it and hook vacuum directly to the water valve.

Yea, the whole heater system is sh$%. We all get one of these problems at some stage, all can be fixed but still a pain in the ass. Moving the temp control and not hearing the motors? Clean the terminals that the switch slides on. These plates have some type of switch lubricant on them from factory and this grease holds dust and dirt. etc. I cleaned mine, and put some new switch lube on it and no problems since.
Another problem is the fan not working on the lower settings. Apparently it can be fixed by something under the glove box?? This is the last problem with my heating system i need to fix. Air in the system, for me was a head gasket, which has just been fixed.

Go here to fix fan low speed.

http://www.supras.com/06/techcenter/...231c19a16cb495

I did this and it lasted for a year. So I went back in and replaced (soldered in place) the low speed wire coil with some small diameter 'stainless steel safety wire' from the local motor cycle shop. (they use it on race/dirt bikes) They will probably give you the 2-3" you need.