You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!
If you have any problems with the registration process or your account login, please contact us.
Heating & Air ConditioningDoes your heater blow cold air? Does your air conditioning blow hot air? Post your all of your technical issues related to your heating, heating core, air conditioning unit and controls here. Don't wait until it is to late to get these important vehicle functions fixed.
It is your Heater Control Valve. If this goes it will not let the hot water circulate through the Heater Core. Yes the hoses will be very hot up to the firewall but this valve lets it circulate through.
__________________
Mark V
1998 Explorer 4.0 SOHC
1998 Windstar GL 3.8
2001 Corvette Coupe 6 Speed
2006 Honda Shadow Spirit 750 http://public.fotki.com/snextime/
If your Exhaust tip is bigger than your cylinder bore, you are a Ricer!
There is no valve in the coolant line from the engine through the heater core to the water pump. There is a complex bypass system composed of steel tubing and rubber hose. The bypass routes coolant past the heater core to the water pump to protect the engine from excess heat if the heater core is blocked.
You need to check the temperature of the hoses that attach to the heater core tubes. Both hoses should be very hot to the touch and close to the same temperature. If the outlet is much cooler or cold then you have an air lock or the core is blocked.
The blend door controls the temperature of the air and is operated by an electronically controlled unit powered through the A/C fuse. Is the fuse OK.
The other doors are usually vacuum operated so you should check that you are getting vacuum. In place of a gauge you can use a finger to detect the suction from the hose.
Low coolant level will adversely affect heater performance too. The coolant bottle should be nearly full when cold, much higher than the mark on the bottle. Ford issued a TSB on this for pre-2000 Taurus.
Hope this helps.
__________________
Art
2000 Taurus SEL Wagon 3.0 Vulcan (daily driver)
1993 Taurus GL Wagon 3.8 Essex
1991 Mercury Grand Marquis LS 5.0
1986 Chevrolet 3/4 ton pickup 4x4 350 with turbo400 and 208 transfer case
1978 Chevrolet 3/4 ton pickup 4x4 custom 6.2 na diesel with turbo400 and 203 transfer case
Planning 2008 Taurus X in a year
I don't think that is off a Taurus, it needs the full flow of coolant through the heater core (or bypass) to the water pump to ensure proper cooling of the engine. That does not look like a shut-off valve, more like a temperature sensor. A Lincoln 4.6 has a valve like that to check the temperature of the coolant before switching the blower fan on. But there is no restriction to the coolant flow.
__________________
Art
2000 Taurus SEL Wagon 3.0 Vulcan (daily driver)
1993 Taurus GL Wagon 3.8 Essex
1991 Mercury Grand Marquis LS 5.0
1986 Chevrolet 3/4 ton pickup 4x4 350 with turbo400 and 208 transfer case
1978 Chevrolet 3/4 ton pickup 4x4 custom 6.2 na diesel with turbo400 and 203 transfer case
Planning 2008 Taurus X in a year
I don't think that is off a Taurus, it needs the full flow of coolant through the heater core (or bypass) to the water pump to ensure proper cooling of the engine. That does not look like a shut-off valve, more like a temperature sensor. A Lincoln 4.6 has a valve like that to check the temperature of the coolant before switching the blower fan on. But there is no restriction to the coolant flow.
__________________
Mark V
1998 Explorer 4.0 SOHC
1998 Windstar GL 3.8
2001 Corvette Coupe 6 Speed
2006 Honda Shadow Spirit 750 http://public.fotki.com/snextime/
If your Exhaust tip is bigger than your cylinder bore, you are a Ricer!
Last edited by mark v; 01-04-2008 at 07:25 PM.
Reason: Link Changed
There is no valve in the coolant line from the engine through the heater core to the water pump. There is a complex bypass system composed of steel tubing and rubber hose. The bypass routes coolant past the heater core to the water pump to protect the engine from excess heat if the heater core is blocked.
You need to check the temperature of the hoses that attach to the heater core tubes. Both hoses should be very hot to the touch and close to the same temperature. If the outlet is much cooler or cold then you have an air lock or the core is blocked.
The blend door controls the temperature of the air and is operated by an electronically controlled unit powered through the A/C fuse. Is the fuse OK.
The other doors are usually vacuum operated so you should check that you are getting vacuum. In place of a gauge you can use a finger to detect the suction from the hose.
Low coolant level will adversely affect heater performance too. The coolant bottle should be nearly full when cold, much higher than the mark on the bottle. Ford issued a TSB on this for pre-2000 Taurus.
Hope this helps.
Having same problem with my 99 taurus. I flushed out the core 2 months ago (flushed both ways). Was working ok until last week.
Now just blows cold air. I checked both hoses (in and out) and were hot. Were is the vacuum hose?
Hi Mark,
I went to the site you quoted and as you noted it showed a heater core for a Taurus. I did as you suggested and went to the Autozone site and searched the cooling system for a 1999 Taurus OHV and they do not list a "heater control valve". Here is the link I used: AutoZone.com | Shopping | Parts | Cooling & Heating
I do not know what that heater control valve fits, but I am sure it is not a Taurus. The Taurus cooling system is dependent upon a full flow through the heater core (or bypass) to avoid overheating. Ford added the bypass because poor maintenance caused heater core blockages due to brown (rust encrusted) coolant. Ford does not use such a valve, I am sure.
If you are still convinced of the use of a control valve in the cooling system between engine, heater core and water pump then I think you should use the Ford parts rather than Autozone parts for your research.
Regards, ABE
__________________
Art
2000 Taurus SEL Wagon 3.0 Vulcan (daily driver)
1993 Taurus GL Wagon 3.8 Essex
1991 Mercury Grand Marquis LS 5.0
1986 Chevrolet 3/4 ton pickup 4x4 350 with turbo400 and 208 transfer case
1978 Chevrolet 3/4 ton pickup 4x4 custom 6.2 na diesel with turbo400 and 203 transfer case
Planning 2008 Taurus X in a year
Having same problem with my 99 taurus. I flushed out the core 2 months ago (flushed both ways). Was working ok until last week.
Now just blows cold air. I checked both hoses (in and out) and were hot. Were is the vacuum hose?
The vacuum hoses in the passenger compartment are behind the center oval shaped unit holding radio and heater controls. You will need the Ford radio removal tools to remove it. These are about $3 in a parts store and either 4 steel wires with a loop on each or two "U" shaped wires. Some people use coat hanger wire.
The heater temperature control door (blend door) is opened by an electronic motor fed by the A/C fuse. That door is likely your problem. The vacuum motors fed by the vacuum distribution panel (attached to the rear of the heater controls on the radio panel) controls the doors for windshield, floor and vents. This is the distribution side of the heated air after the blend door. Distribution is not your problem, it is the blend door.
Hope this helps.
__________________
Art
2000 Taurus SEL Wagon 3.0 Vulcan (daily driver)
1993 Taurus GL Wagon 3.8 Essex
1991 Mercury Grand Marquis LS 5.0
1986 Chevrolet 3/4 ton pickup 4x4 350 with turbo400 and 208 transfer case
1978 Chevrolet 3/4 ton pickup 4x4 custom 6.2 na diesel with turbo400 and 203 transfer case
Planning 2008 Taurus X in a year
The vacuum hoses in the passenger compartment are behind the center oval shaped unit holding radio and heater controls. You will need the Ford radio removal tools to remove it. These are about $3 in a parts store and either 4 steel wires with a loop on each or two "U" shaped wires. Some people use coat hanger wire.
The heater temperature control door (blend door) is opened by an electronic motor fed by the A/C fuse. That door is likely your problem. The vacuum motors fed by the vacuum distribution panel (attached to the rear of the heater controls on the radio panel) controls the doors for windshield, floor and vents. This is the distribution side of the heated air after the blend door. Distribution is not your problem, it is the blend door.
Hope this helps.
Miss diagnosis by me, earlier I said both heater core lines were hot.
I checked the core input output lines again. The top one was cool , bottom that feeds from the thermostat was hot to touch. Think the core is clogged again.
When on vent the air is warm. If I vary the temp control (it is a manual control) the air temp does change.
So, I know the temp control works, the coolant going into the core is hot (Line that goes to the right). Fluid coming out (line goes to the left) is cool or cold.
I will try flushing the core again Sunday. I really flushed the core out 2 months ago by isolating it and putting a hose to both in & out lines. Also flushed the cooling system.
Shopping for new cars can be a stressful experience especially if you don't have the right information. Our new car research center at CarEverything.com can help relieve this stress and bring the joy back to new car buying!
The Car Blog, or TCB for those who are acronymically inclined, is alive because some of today's top Web designers needed a place to drool and bitch about their motor vehicle obsessions.
Read the auto blog at Automotive.com to get the latest news and opinions, view the newest concept cars, and join discussions with auto experts from around the world.
Linear Mode
