heater answers??

mrnickleye · 11-21-2005, 08:38 PM

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

Burn N' Up · 11-23-2005, 09:53 PM

What is the VSV?

mrnickleye · 11-24-2005, 12:14 AM

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.

Jebus · 12-01-2005, 05:37 AM

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.

mrnickleye · 12-01-2005, 06:38 AM

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.

RogerH · 12-01-2005, 09:52 AM

I took the heater control panel from my 90turbo and put it my wifes 87NA and the everything works OK. I don't think the panel changed during the Mk3 production. I've bought a panel for ?25 from a scrapyard but haven't fitted it into mine yet. I took the broken control panel apart all looked OK the slide contol seemed to be a sealed unit but I'll try taking it apart for cleaning.
The resistor for the heater lies in the air duct on the bulkhead at high level in the passenger foot well. The smallest coil that contols the first setting of the fan breaks or falls apart. It can be repaired as described in the other replies - life is too short - I bought a new one!
Another problem I had before was the fan not working at all. I took it out and found the motor full off dust and dirt it seems to find its way in through a black tube which I think is for cooling. I cleaned the motor up and put a piece of linen over the end of the black tube to act as a filter - its been OK since.

Jebus · 12-02-2005, 04:16 AM

Quote:

Originally Posted by mrnickleye

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.

Done. I replaced the broken coil with some fuse wire of about the same gauge, wrapped it around a pen, 10 coils like the original. Works like a charm. Allthough the surfaces were really filthy and took a bit of rubbing with emery paper to get the solder to take to it. Thanks again for the help.

Pearl Mica · 12-03-2005, 09:46 PM

hi, just got a '90 7mgte manual in black/pearl mica, i think i got a BHG (gives a little puff of smoke sometimes on down change) freind thinks it could be the valve stem oil seals? either way i'm gonna have the head off. get it skimmed and new gaskets sets in. got the same heater problem (fan blows but only cold air), i'm a bit of an novice when it comes to getting my hands dirty and all the technical stuff. as i'm in the uk, i'm guessing that the vsv is going to be swapped over on the opposite side as we have our sterring wheel on the right here. thats right yeah? and where exaclty is it, can i access it from the footwell inside or in the engine bay? any help/pics would be great.

flight doc89 · 12-05-2005, 07:07 PM

my air blows fine, but it doesn't blow hot or cold.

It doesn't matter what the temp is turned to, it just blow outside air (or recirculated, if that button is on). If i turn the AC on, the fan clutch kicks in and the air speeds up, but it does't change temp at all, so in the summer, i roast without putting down the windows, and in the winter, i freeze......HELP!

12-01-2005, 05:37 AM	#4
Jebus Stock Join Date: Dec 2005 Posts: 25	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. __________________ If only my Supra had a Novarossi!

12-01-2005, 09:52 AM	#6
RogerH Stock Join Date: Nov 2005 Posts: 5	Heater control panel I took the heater control panel from my 90turbo and put it my wifes 87NA and the everything works OK. I don't think the panel changed during the Mk3 production. I've bought a panel for ?25 from a scrapyard but haven't fitted it into mine yet. I took the broken control panel apart all looked OK the slide contol seemed to be a sealed unit but I'll try taking it apart for cleaning. The resistor for the heater lies in the air duct on the bulkhead at high level in the passenger foot well. The smallest coil that contols the first setting of the fan breaks or falls apart. It can be repaired as described in the other replies - life is too short - I bought a new one! Another problem I had before was the fan not working at all. I took it out and found the motor full off dust and dirt it seems to find its way in through a black tube which I think is for cooling. I cleaned the motor up and put a piece of linen over the end of the black tube to act as a filter - its been OK since. Last edited by RogerH; 01-18-2006 at 05:16 PM.

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11-21-2005, 08:38 PM	#1
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	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

11-23-2005, 09:53 PM	#2
Burn N' Up 3" Exhaust Join Date: Sep 2005 Posts: 238	What is the VSV?

11-24-2005, 12:14 AM	#3
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	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.

12-01-2005, 06:38 AM	#5
mrnickleye 1000whp postwhore Join Date: Jun 2005 Location: Mojave Desert, Calif. Posts: 1,705	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.

12-03-2005, 09:46 PM	#8
Pearl Mica Stock Join Date: Nov 2005 Location: Leamington Spa Posts: 6	hi, just got a '90 7mgte manual in black/pearl mica, i think i got a BHG (gives a little puff of smoke sometimes on down change) freind thinks it could be the valve stem oil seals? either way i'm gonna have the head off. get it skimmed and new gaskets sets in. got the same heater problem (fan blows but only cold air), i'm a bit of an novice when it comes to getting my hands dirty and all the technical stuff. as i'm in the uk, i'm guessing that the vsv is going to be swapped over on the opposite side as we have our sterring wheel on the right here. thats right yeah? and where exaclty is it, can i access it from the footwell inside or in the engine bay? any help/pics would be great.

12-05-2005, 07:07 PM	#9
flight doc89 3" Exhaust Join Date: Oct 2005 Location: Tuscaloosa, AL Posts: 53	my air blows fine, but it doesn't blow hot or cold. It doesn't matter what the temp is turned to, it just blow outside air (or recirculated, if that button is on). If i turn the AC on, the fan clutch kicks in and the air speeds up, but it does't change temp at all, so in the summer, i roast without putting down the windows, and in the winter, i freeze......HELP!