vacuum, heater controls, heater control valves n more help?

terryduanemiller · #1 12-15-2010, 04:26 PM

been having heating problems. in really cold weather loss of heat. temp gauge drops all way to C, but works fine in 40+ weather. i have removed components in dash n inner fender. all vacuum lines are intact. but no vacuum to heater control valve in engine bay. canister is working in and out. it seams to be multiple issues combined into 1. any thoughts or suggestion? heater contol module? does any one know if hcv open via vacuum for heat? or closes via vacuum for a/c?...... thanks in advance

TenSilver · #2 12-15-2010, 04:39 PM

A couple of questions.
Your temp gauge goes to "C" after the engine is at operating temp?
If so then it sounds like your thermostat is sticking.

I think there should be a vacuum operated heater control valve in line with one of your heater hoses going to your heater unless it's been removed.

FireRanger · #3 12-15-2010, 04:47 PM

Quote:

Originally Posted by terryduanemiller

been having heating problems. in really cold weather loss of heat. temp gauge drops all way to C, but works fine in 40+ weather. i have removed components in dash n inner fender. all vacuum lines are intact. but no vacuum to heater control valve in engine bay. canister is working in and out. it seams to be multiple issues combined into 1. any thoughts or suggestion? heater contol module? does any one know if hcv open via vacuum for heat? or closes via vacuum for a/c?...... thanks in advance

You're making this way to complicated. Vacuum has nothing to do with this. The fact that the temp gauge drops down to C means this has absolutely nothing to do with your heating and control system. If the engine is not getting hot, then as a side effect, you will obviously not have any heat. Trying to find a heating problem on a cold engine is like calling the cable company to complain about no TV when the power is out.

As stated above, your thermostat is stuck open. This prevent the engine from getting warm. Replace and all will be well.

terryduanemiller · #4 12-15-2010, 04:55 PM

temp guage rises. but never get up to full temp in really cold weather. hcv is still in line. but no vacuum to it, tried heat n a/c no difference.

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Quote:

Originally Posted by FireRanger

You're making this way to complicated. Vacuum has nothing to do with this. The fact that the temp gauge drops down to C means this has absolutely nothing to do with your heating and control system. If the engine is not getting hot, then as a side effect, you will obviously not have any heat. Trying to find a heating problem on a cold engine is like calling the cable company to complain about no TV when the power is out.

As stated above, your thermostat is stuck open. This prevent the engine from getting warm. Replace and all will be well.

re read my post. fyi, vacuum controls the heating n cooling controls..... no vacuum to heater control valve in engine bay. thermostat is new.

FireRanger · #5 12-15-2010, 05:09 PM

I read it several times (one has to read it several times to make sense of it). Since you're not typing in clear english sentences, it is difficult to piece this all together. And you're totally contradicting yourself now since you said it drops to all way to C. We can't help you if you aren't going to explain whats going on in way that makes sense.

The control valve in the engine bay uses vacuum to CLOSE it. This only occurs when you set the HVAC for off or max ac. Without vacuum, it has a spring that returns it to open. You can ram a screwdriver in the vacuum hole to force it open if you think it is stuck.

And the bottom line remains that no heat is going to exist until you fix the reason the engine isn't warming up. The needle dropping AT ALL means something is wrong. The t-stat is bad or installed wrong is the most common and basically the only thing that can cause this.

While you're at it, check your coolant level on a COLD engine so you don't get burned. The radiator should be full and the tank should be half full. 50/50 mix of water and antifreeze if you need to add more.

The vacuum on the HVAC controls has nothing to do with temperature. It only controls the doors that direct the air to the different vents. If vacuum is completely lost, the doors are all spring loaded and fail to full defrost. So even if you have a vacuum loss, you will always still get air flow full power out the defroster vents. Again, NOTHING to do with temperature.

The temperature knob controls a blend door that regulates how much of the air passes through the heater core. Since you haven't bothered to tell us what year truck you have, nobody knows whether this is cable driven off the knob or electric by a servo motor. Either way, this is irrelevant until you fix the aforementioned engine temperature problem.

terryduanemiller · #6 12-15-2010, 05:49 PM

1999 2.5L ...i asked if hcv opens or closes per hvac control selection. cause changing from heat to a/c didnt effect vacuum on that line to heater control valve.. maybe its installed backwards?...... thought maybe it was hot to cold selector since its electronic... maybe t-stat is bad.. i am open for suggestions. i am 11yr ASE certified but never operated on this issue... currently snowed in with no acces to my manuals or searching via internetat the moment....... i dnt need a lesson on how system works, rather what has failed... just need some simple questions answered. and some suggestions. havent ruled out any other than stated. i appreciate your time n effort. have no interest in an argument. note: i am repling via mobile if there is a communication issue. PC is being repaired.

FireRanger · #7 12-15-2010, 07:30 PM

Ugh. Listen. I'm not sure why you're asking for help if you are going to keep denying facts and answers presented to you. I and many others here have dealt with this very issue about 100 times in the last 2 months on FRF alone. If you do not want to listen, then stop asking. It frightens me that you claim to be ASE certified. You clearly do need a lesson in how the system works because if you didn't we wouldn't even be having this discussion. Some of this stuff is high school auto shop material.

Everything I said is hard fact. No you can't have the valve in backwards, it doesn't work like that. You keep hovering on this vacuum loss when it is only a minor secondary issue. Until you fix the problem preventing your engine from warming up, it is irrelevant. As I said, you will get blazing hot heat out the defroster vents even with a total loss of all vacuum.

rwenzing · #8 12-15-2010, 08:26 PM

To answer your question, the heat diverter valve defaults to open in the absence of vacuum. It only closes off flow to the heater core in 2 modes of the HVAC panel: "OFF" and "MAX AC". All six of the other switch positions (including "AC") have no vacuum and the valve open, allowing hot water flow to the heater core.

I agree with Matt. Your biggest problem appears to be that the coolant isn't coming up to temperature. That sounds like a thermostat problem.

terryduanemiller · #9 12-15-2010, 09:21 PM

ok smart ass punk, i never asked for your opinion of me or my knowledge.. you're not dealing with a kid here.. i never said u was wrong? wtf is your problem?.. i was only asking questions. never ruling out new t stat was faulty. go aggrivate some one else.

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Quote:

Originally Posted by rwenzing

To answer your question, the heat diverter valve defaults to open in the absence of vacuum. It only closes off flow to the heater core in 2 modes of the HVAC panel: "OFF" and "MAX AC". All six of the other switch positions (including "AC") have no vacuum and the valve open, allowing hot water flow to the heater core.

I agree with Matt. Your biggest problem appears to be that the coolant isn't coming up to temperature. That sounds like a thermostat problem.

thank you very much... all have have stated, wasnt directly saying i have no heat cause of vacuum issue..
but there is a vaccum issue. i have no vacuum to valve on any setting. hince the ?'s about the valve its self.

sheltonfilms · #10 12-15-2010, 11:28 PM

I had the same problem on my 2000 2.5, it was actually a clogged heater core. You would be able to tell if your heater control valve could get some vacuum. Mine would show a realy cold reading in cold weather when the heat was on, but when you turned it to OFF it closed the heater valve and it bypassed the core causing the temp gauge to rise quickly. Since most V6's have a 2 port HCV they have a bypass that is always open, but with the four cylinders with the 4 port HCV, the bypass is closed off when the heat is on and is diverted to the heater core. If the heater core is clogged it is hard for the coolant to flow, even over the coolant temperature sensor. THat is why you get no temperature and no heat.

I would take off the hoses to your heater core and backflush it. Make the water flow the opposite direction into the core as it would flow by the engine. This way it dislodges the crud stuck inside. You can also used compressed air.

terryduanemiller · #11 12-16-2010, 12:59 AM

Quote:

Originally Posted by sheltonfilms

I had the same problem on my 2000 2.5, it was actually a clogged heater core. You would be able to tell if your heater control valve could get some vacuum. Mine would show a realy cold reading in cold weather when the heat was on, but when you turned it to OFF it closed the heater valve and it bypassed the core causing the temp gauge to rise quickly. Since most V6's have a 2 port HCV they have a bypass that is always open, but with the four cylinders with the 4 port HCV, the bypass is closed off when the heat is on and is diverted to the heater core. If the heater core is clogged it is hard for the coolant to flow, even over the coolant temperature sensor. THat is why you get no temperature and no heat.

I would take off the hoses to your heater core and backflush it. Make the water flow the opposite direction into the core as it would flow by the engine. This way it dislodges the crud stuck inside. You can also used compressed air.

i did that last winter and it worked fine untill few days ago.. got really cold here... truck has new rad' and completely flushed in summer.

FireRanger · #12 12-16-2010, 05:22 AM

Quote:

Originally Posted by terryduanemiller

ok smart ass punk, i never asked for your opinion of me or my knowledge.. you're not dealing with a kid here.. i never said u was wrong? wtf is your problem?.. i was only asking questions. never ruling out new t stat was faulty. go aggrivate some one else.

Excuse me? You brought it up when you started throwing your "certifications" around because you didn't like my answer and tried make yourself sound special (which utterly failed btw). If you don't want people questioning your specialness, then don't give them reasons. I answered all your questions and gave you all the directions to investigate in my very first reply. Then expanded on them even more in my second reply. And all you do is complain or try to say why its something else.

Anyway, you have your answers and nobody is going to give you something different or better. So try to fix it or drop it.

sheltonfilms · #13 12-16-2010, 02:57 PM

[YT]http://www.youtube.com/watch?v=prELIRxxOCU&feature=related[/YT]

terryduanemiller · #14 12-16-2010, 04:38 PM

Quote:

Originally Posted by FireRanger

Excuse me? You brought it up when you started throwing your "certifications" around because you didn't like my answer and tried make yourself sound special (which utterly failed btw). If you don't want people questioning your specialness, then don't give them reasons. I answered all your questions and gave you all the directions to investigate in my very first reply. Then expanded on them even more in my second reply. And all you do is complain or try to say why its something else.

Anyway, you have your answers and nobody is going to give you something different or better. So try to fix it or drop it.

who are you to tell me what to do? no one else seems to have problem answering my thread in a mannerly fashion.

specialness? what makes u think i ddnt like ur answer, they where logical but u only answered one ? to no heat, i had other questions moron. just stay off my threads. dnt tell me what to post or drop.

i have worked in collision and at a GM dealership, it is logical i have never investigate how fords f'n heater controls work. was only asking for some direction n info. not demands from u.

one more time, piss off

sheltonfilms · #15 12-18-2010, 01:46 AM

Are you in Kentucky or Florida now? Reason why I ask is if you want to just replace your heater core and you live in KY I would say drive down here to Knoxville and I will help your replace it. (done it before). Since you are a fellow Ranger driver my rate is free. A 12 pack would be good gesture.....lol.
\

I also have a vacuum gauge so I can help you find that leak as to why you don't have vacuum at your HCV.