What is this in my heater hoses?

[tcbarney]

Can anyone tell me what this doohickey is? See the pics here at my Yahoo photos site:
tcbarney's Yahoo photos

I'm referring to the cylindrical thing with the small hose/cable attached to the top. It's just right of center in the first photo, dead center in the second.

It's leaking coolant...

Thanks!

 

[Robb]

I would have to guess that it is your Heater Control Valve. It opens when you want heat inside, closes when you don't.

Robb

 

[Maniak]

Thats exactly what that is.. a heater control valve...

I believe they started using those in 94 or 95. Without them, hot water goes into the heater all the time..

In the summer (at least here in Az), that makes your AC 5 or so degrees hotter...

I put one of those on our 1992 and it really helps.. I could get the a/c to drop 5 to 7 degrees by using that valve..

Its not very expensive to replace if it starts leaking and is worth replacing (instead of bypassing)

~Mark

 

[Strike12]

Not sure but I think its your temperture control valve for your interior temp , I thought their usually inside the cabin but my x is older so maybe they changed the location.

 

[yob_yeknom]

Nope, they're always located outside under the hood. They are vaccuum operated. They open and allow hot coolant to flow through the heater core, which is inside the vehicle, when the heat is turned on. They are closed when the heat is off so the coolant in the heater core will remain cold.

 

[tcbarney]

You guys are great! Now I know what to ask for to stop this leak.

It would be this little jobber:


Dead Link Removed

Thanks!

 

[Gator]

Heater control valve

I too have been experiencing the mysterious anti freeze smell in the engine bay on both of my 1997 explorers.
One also has experienced intermittent failure of the heater to supply hot air when requested. I thought that I would be replacing that thermostat AGAIN, but now realize that it may be the heater control valve and I intend to change both of them . NOW THE QUESTION?

Where is the heater control valve located on the SOHC V-6 in my 1997?

On the V-8, it is near the firewall on the passenger's side in plain sight. On the SOHC it is not in that location, but I think that I may see it down by the water pump in front of the engine on the passenger's side, in a less accessible location. If someone has replaced on on an SOHC engine PLEASE tell me if I am right and how difficult it was to replace.

Thanks to all!!

Gator

 

[JLP]

My '96 had the leaking heater control valve issue for about a year. It only leaked when the AC/Heat/Def selector swith was in the OFF position. I finally replaced it and the job was about 15min and $17 for the part. No more leak.

 

[BradE.]

I just replaced mine 2 days ago on a 1997 4.0L OHV. Mine was also leaking in the OFF position and I kept smelling coolant outside of the car. I didn't even notice this was leaking until I was changing the belt and saw it dripping. It's all fixed now, no more leaking and no more coolant smell.

The part was $17 from my local Ford dealer and took about 15 minutes to replace. Just pulll the vac line. Then unhook the 4 heater hoses and replace them on the new valve. Reconnect the vac line, and you done. The bottom hose clamps can be somewhat of a PITA, but it's still pretty easy.

 

[Gator]

I' m glad that it was easy for you, but....

Where is it located on the SOHC V-6 PLEASE!

It doesn't sit on the top of the heater hoses in plain view as it does on the OHV or the V-8.

Thanks again

Gator

 

[yob_yeknom]

Get under your truck and look up at the front of the engine. You will see it. Weird place to put it IMO.

 

[Gator]

Thanks for confirming that it is in front of the engine on the SOHC V-6 rather than in plain sight on the heater hoses by the fire wall on the passenger's side as it is in the V-8 and OHV engines.

Now I'll get the part and "Let the fun begin".

Gator

 

[SVO LOU]

Originally posted by Maniak
Thats exactly what that is.. a heater control valve...

I believe they started using those in 94 or 95. Without them, hot water goes into the heater all the time..

In the summer (at least here in Az), that makes your AC 5 or so degrees hotter...

I put one of those on our 1992 and it really helps.. I could get the a/c to drop 5 to 7 degrees by using that valve..

Its not very expensive to replace if it starts leaking and is worth replacing (instead of bypassing)

~Mark

That's a great idea, Mark. Can you tell me how you control the valve on a vehicle which didn't have a control valve to start with? Where do you have the vacuum line from the valve going to?

Thanks.
Lou.

 

[Maniak]

I put a T on the vacuum line that is used to control the vent door. Pull the glove box out and look in the bottom right corner, you will see a vacuum motor. I connected it right there. I then ran the new vacuum line through the firewall and up to the heater lines where I put the control valve.

When the heater control is set on "MAX A/C" it closes the heater control valve and doesn't let hot water into the heater.

When my Heater control is set to anything else (panel, floor etc) it opens the heater control valvle and lets the hot water in.

~Mark

 

[SVO LOU]

Thanks Mark. That's exactly what I was curious about.

Lou.

 

[alphabets13]

mine was leaking too. just replaced it, real cheap, real easy.

 

[darktrance]

Dangerous Thinking

Adding in the control valve brought an intersting idea to mind. Do you suppose that I could modify the heater control valve to assist with my broken blend door issue?

If I had just regular air blowing around without the volcanic temperatures on my 'vent-only' setting, I could blow of that blend door repair for another season or so.

 

[410Fortune]

I dont know about theblend door issue, but I too added this valve to my 88 BII with a 93 OHV 4.0L.

Now on my truck it was a little more tricky to add the valve.

The problem is during the summer hot coolant flowing through the heater core in a BII = hot air on the passengers feet. I do not have AC in my truck (who needs AC when your gonna chop the top) so it gets pretty annoying to have hot air blowing into the truck.

However since my donor engine was from a 93 and the truck is not equipped with the vacuum controlled heater settings, I had to get creative.

I found a vacuum solenoid from an older Ford 2.8L v6.
This solenoid is simple, it allows vacuum to flow through it in the open position and nothing to flow through in the closed position.
I wired this sucker up with a simple relay and switch, so in the summer time I put the switch off and in the winter it is on, this with a vacuum tree tied into the engines vacuum canister allows me to shut off the flow of hot coolant to my heater core, greatly reducing the hot air inside the truck.

It works great!!

Now to convert the old AC compressor into a full fledged on board air setup.......

 

[Maniak]

410,
What was the vacuum solenoid to? I need a couple of those for some mods I'm trying to do to the X, but its hard to find them in a yard, and of course a dealer won't know what I want when I say I want a vacuum solenoid.

~Mark

 

[410Fortune]

aNY 2.8l POWERED bii/rANGER WILL HAVE THESE SUCKERS.
Also you can find them on later model Explorer's, and the ones for the heater control are 95+ under the pass side kick panel above the EEC.

On the older trucks they are mounted on the passenger side fender wall under the hood. I have some spares if you want one drop me an email. I will have to dig them up but I think I know where they are........