89 ta, air blows out but no heat, the gauge has a normal tempurature, i recently did a coolant flush, i read from searching there could be air in the system, what's the proper way to get it out? I dont know where to look for other things, could someone tell me where the heater core is located and this valve i see alot of people referring to?

 

The heater hoses valve, per se, actually (I think) only closes when the AC is set to max. Otherwise it stays open. Try this: Run the car up to temp and set it to heat. Feel the heater hoses that lead to the heater core, directly at the firewall. If both are warm/hot, fluid is circulating through and through correctly and suspect would go to the diverter air diverter valves on the interior.

If the hoses are cool to the touch, even through the heat is set to max, then yes, the valve would be suspect (in which case, one side of the valve would be hot and the other cool).

 

Well, I didn't put the heat on, but all 3 hoses coming off that valve are hot. What are these diverter air valves? How do I get to them? Air does blow out, it's just not warm or hot. Could it be my heater core?

 

What about the return line from the heater core? If that hose is warm/hot also, that means that coolant is making it through the heater core without issue.

 

Is that one also connected to the heater control valve? There's 3 hoses going into it, they're all hot.

 

Most likely the valve is your problem. It's about a 15 dollar part. It prolly had the same problem as mine. Frozen in one position. Soon as I replaced mine, the heat worked again.

 

I was going to pick up a valve but I was under the impression that if all hoses were hot that the valve wasn't the problem? Also, the hose coming back to the radiator (passenger side) is not nearly as hot as the other hoses, but it's not cold either

 

Hmmmm, well, you're not reporting any leaks so... It can really only be one of two or three things. The valve is bad. There is some major clog before the water hits the core which is about as unlikely as it gets and finally the doors aren't moving. When you set it to defrost or set to heater, do you feel any difference in the air? Does it actually divert air to the defrost vents? Do you hear the doors moving positions in the dash? If not, you may have a problem where the doors aren't moving position when you change settings. You should prolly take the valve off at the least and see if there is actually water in the hose going to the firewall. I suppose the valve could be partially open allowing a small amount of hot water to pass but not enough to get the air hot. Really though, at normal temps, those hoses should be almost too hot to touch, like the upper/lower radiator hoses. If they aren't I doubt a lot of water is passing through them. For that fact, you might wanna replace those hoses attached to the valve. They are heater hoses running the same water as the radiator hoses and can exhibit the same problems as an old unchanged radiator hose. Spongyness, bloating, and can come apart on the inside, etc. That includes new clamps.

I dunno, but I tend to find a problem and then replace ancient parts. I mean, myself, I would replace the valve and hoses just because and then mark down when I replaced them for future reference. Those parts are really old by now and mostly neglected until they fall apart because noone ever thinks of them. Like vacuum hoses which I'm replacing now. Mine are only 14 years old and are either dry rotting or turning to the consistancy of peanut butter and just gooey.

Best bet, take the valve off, give it the once over, hoses included, check for water in all the lines, etc and go from there. The valve may break into pieces though, so maybe do it at the auto store. Mine did at least a few years ago.

 

The air tempurature doesn't really change with heater on. The hose going out of the valve which I assume runs to the heater core (goes back towards firewall) hot to the touch. Even if I haven't tried running the heat the hose coming back (to radiator) is warm.

 

Well, the only thing it can be, if it's not the valve is the doors themselves not moving. I can't remember if it's cable, vacuum or both actuated doors. Something is broke, disconnected or some such down there behind the dash. I can't really tell you what to do for that. Myself, I'd prolly tear into the dash and check everything. Pull out the control panel/unit, follow the cables/hoses and check to make sure the doors open and close.

On a slight side note. If you do tear into the dash as far as the doors themselves, you might think about replacing the little foam like gasket around the doors. It tends to get brittle with age, fall off, come out the vents and then the doors don't seal properly anymore. But that's not THAT important. Just an "if you're already down there" suggestion.

Also, if you head into the dash, make sure the cars heated up. When you reach the door where the heater core is, force it open manually with the heat on and see if the air is hot coming out. If not, your core or valve is bad, regardless of what the hoses feel like. Prolly the doors/door controls though.

 

i too am having a heater problem. NO heat, i can hear the doors move and the position of air changes. Im going to have to take apart my heater core cover and see whats gooing in there. I just replaced my valve, heater core, radiator, thermostat and new rad hoses. STill no heat ...this is starting to irritate me

 

Ok, let me do this properly for both of you instead of the way I've been explaining it. I'll go through it like it was on my own car instead of the bits and pieces I've been doing.

First, my car has no heat. Ok. Automatically check the diverter valve. First, remove the vacuum hose from the valve. I SHOULD hear a noise, like a suction/thump noise when the hose is removed. This means my valve should be functioning properly as the diaphram on the inside has moved. This also probably means the long hard plastic vacuum hose is good too, but I check it anyway for cracks and the rubber boot that goes on the valve. Next, I check all the hoses going to and leading from the valve. I also check for leaks at both ends of all these hoses. If they look and feel ok, I remove them all and run a flow of water through them to check for blockages. As long as the hoses are relatively new and not soft/spongy/coming apart inside, they are fine. I put it all back together.

Now I drive the car and get it to normal operating temperature for a bit and check the air. If it's still not hot, I now check the 2 hoses connected to the heater core. This is the same water running through the engine/radiator and the hoses should be the same temp as the radiator hoses. Inlet and outlet. The outilet will prolly be somewhat cooler, but not THAT much. If the outlet from the core is cold or just warm, there's a restriction in the core itself. If both hoses check out hot and the air is still cold, it's time to check out stuff inside the car.

First I check to make sure the air is actually powerful coming out of the vent. If not or if I don't have all speeds, such as high speed, there's a problem right there. High speed missing means a bad high speed blower relay near the blower motor. Little or not very powerful air flow means either a bad blower motor/wiring problem or restrictions in the ductwork. If the air is strong, then I check door controls. If I hear the doors moving and can set it to defrost/etc and the air moves to the appropriate vents, the doors should be working fine. To be on the safe side, I will pull out the control unit and check all cables, wiring and hoses connected to the unit and any running to the door controls. I will check to see visually if the doors move by removing whatever necesssary to get at them in the dash. If they move, I will turn the heat on, get the doors open properly and stick my hand down where the air flows past the heater core into the ducts. I will also carefully touch the heater core itself if possible to make sure the thing is actually hot enough to warm the air(and really, with the car at full temp the air coming out of there should be REALLY hot or at worst hot) If the air is NOT warm/hot, the only 2 possible causes are a restriction in the heater core/hoses or a bad valve. If the air coming out of the core is hot but the air coming out of the vents isn't, there's a duct problem. Check all the passages, doors and replace as many of the foam like seals as possible. Those seals will be on the door edges and on the ends of each duct section.

Getting to the core itself and verifying whether the air is hot or cold coming out is about the last troubleshooting step you can do. It will tell you what's going on. If you replace the core and the valve and the air is STILL not hot, replace the heater hoses. If the air is STILL not hot, either your car is possessed by the spirit of Frosty the Snowman or you haven't completed all the steps.

Hot hoses + hot core = hot air.
Hot hoses + cold NEW core = water passing through the core via Antarctica via the twilight zone
Hot hoses + hot core - hot air = air passing through Antarctica via the twilight zone

If you can't get hot air with all the steps above I don't know what to tell you. I'd be at a total loss. Maybe consult an AC repair place or the dealer.

 

thanks alot bro, im going to have to print this out, i have checked everything except the heater core hoses. I never pulled em out and inspected them. As far as the heater core being hot i'll have to take apart the cover again . LAst time i was there i did see the doors move. I pulled out the control unit and all lines running to it had vacume and worked properly. One more thing, THe vacume line that was running to the heater control valve has no vacume. So i found a way to run a vacume line to it. IS there any way that it will not work if there is another vacume line source connected to the valve. ANd yes i did replace the valve. I also hear a somewhat bubbling noise coming from my dash, perhaps i have air stuck in the core from when i replaced it

 

Alright, since you haven't checked the hoses yet, add this to your list. Check the OTHER ends of the hoses inlets/outlets. Not just the hoses and where they enter/exit the core. And check EVERY hose connected to the system. Lemme try and get that straight here.

Ok, first, I just thought of something. Make sure those hoses aren't reversed/on backwards. They are so close to each other, it wouldn't be hard to swap the inlet with the outlet and not realize it. Inlet hose should be hot, outlet should be warm to hot. If BOTH are warm, that's a problem.

Now, what I mean with the hoses. Backcheck everything. Follow the hoses and connections back to wherever they go. I've never had to go past the valve so I'm not sure where the hoses all go to/come from. I THINK they have routing through the throttle body and somewhere into the back of the engine, I think. Obviously you won't be able to check anything past the engine fitting on the one hose, but on the other, trace it past its point of entry/exit.

Ok, I just checked the shop manual. Contrary to what I've seen a few people state, if you have that mushroom valve, then when the hetaer is off, the valve is CLOSED and NO water is passing through the heater core inlet hose. Just to check, put the AC on cool and check the core INLET hose. It should be cold and stay cold. If it is cold, turn the heater on. The hose should now get hot. If not, same problem, bad vacuum. Grabbing another random hose and plugging it in won't do any good as it's not getting the proper, err, signal/pressure/whatever to actuate the valve. Your bypass vacuum hose may have vacuum but it won't be able to do anything of any merit other than sit there. You need to find the source of the vacuum leak/clog and fix it. You're prolly gonna have to follow the hard plastic hose through the firewall first, disconnect it and then blow air through it to make sure it's not clogged. If it's not clogged, plug one end and blow air through again to check for breaks/leaks anywhere.

After that you need to go even further past the hose and follow the vacuum system in out and around the inside f the car and inevitably back into the engine compartment and keep checking the hoses as above. Once you hit rubber hose, treat it a bit rough. Bend it, squeeze it, pull on it and check the ends carefully. If it's old, it's likely to be in terrible shape and need replacing. Sooner or later you're gonna hit vacuum. I dunno where, but it can't be too far. I mean if you have a severely messed up vacuum system you're likely to have AC/Cruise Control problems. I THINK the vacuum is supplied through the passenger side rear of the plenum near the map sensor(on mine) Yours, dunno. Mine has an AC check valve which then splits off to the cruise control module and from right before the cruise control module to the ever amazing orb of power. The other split goes into the firewall to the AC system.

I just replaced ALL those hoses as they were looking and feeling like hell. I wish I had some expereince tearing that part of the system apart and I could do better than take guesses and maybe look heres. If that new valve isn't opening and closing then you've got a vacuum leak/clog and at the very least, is one of your problems. At best, it'll fix the whole thing.

If the hard plastic hose is bad, best to find replacement hard plastic hose. I wouldn't go monkeying with the design and use rubber hose and find out it won't work still.

By the way, I dunno if you have that ac check valve or if it is even related to your problem, but if it IS bad, it's a 5 dollar part. Myself, I bought a new ac delco part, but I also saw the SAME valve in my local auto parts store in the motormite/help isle. You know, all those general repair parts. Pedals, brackets, bolts, etc. It was listed as a check valve under the GM only usage.

You'll get this thing fixed, not to worry. and then you'll be an expert on heater cores, lol.

 

your full of information , this should be a sticky


btw where does that hard vacume line that is plugged into the mushroom type valve start? DOes it go into the control unit?

 

That I don't know. My basic assumption on the system is that yes, it goes to the control unit and another line goes out the firewall to that check valve I mentioned, but, that is only a guess. I've never had the control unit out or followed those lines back. It looks like, on first glance that the cruise control and the orb of power are fed directly from the passenger side rear of the plenum. A 3 inch piece of hose from there goes to the check valve, one hose goes from the valve to the cruise control(bout a 6 foot length of hose). A t fitting before the cruise control goes to the orb of power(maybe a 2-3 foot hose). The piece past the t fitting going to the cruise unit is maybe a foot or so. A line from the cruise control heads into a tape/wrapped wire/cable assembly and looks like it enters the car. I doubt this is what you'll need, but you may need to look at the orb and it's line back to the valve. It was very difficult for me to get at on the driver side under the battery, but that hose was in awful shape. My hand turned black just grabbing hold of the hose. And that wasn't dirt, it was the hose itself coming apart. The other exit from the valve is a VERY short piece of rubber hose. About 1-2 inches and was in HORRENDOUS shape. I mean it was a gooey/putty consistancy and had to be cut off the fittings with a razor so i could match the length to a new piece of hose. That hose connects to a plastic fitting which connects to a rubber elbow that goes into another hard plastic line. This line I assume goes to the hvac control unit and thats where the OTHER hard plastic line going to the mushroom valve gets its vacuum from. I haven't been able to find the rubber elbows or that rubber fitting on the end of the other hose going into the mushroom valve. Mine were in newish/good shape, but I'd have liked to have replaced them anyway.

One or more of those lines is most likely your problem. Not sure if the orb could be a problem, but as I have no clue when it functions, other than it stores vacuum for use. The hose sizes should be written on the hoses themselves. like 5/32, 7/32, etc. You really need to use the exact sizes. I didn't get enough kinds of hose at first and just could not shove smaller hose on a larger fitting. Not wise either. It'd stretch the hose too much and make it more likely to split sooner. Also, match the lengths near exactly. I founf they stayed in a good spot that way. Too short or too long made them either too close to hot metal or too floppy and likely to bounce all over the place. Reroute them to the same places too, even if it's just between some cables or behind some random part. This keeps the hoses "in line" and not likely to get kinked, melted or anything. Do one at a time or you'll forget where each hose routed exactly too.

Regarding plastic fittings. If you are replacing the hose and it won't slide off easily, do NOT go yanking it off like Hercules to pull it off. Just slit the end with a razor. You don't wanna break a fitting and have to go hunting for a replacement.

If you have cruise control, see if it works. If not, and considering the valve vacuum line doesn't work, I'd suspect that ac check valve I mentioned. along with rotten lines. For 5 bucks, worth replacing anyway. I found mine to be, as usual, in lousy shape. It's hard to explain, but the plastic fitting areas were, well, eaten into in very odd ways by the hose I guess, or something. It worked still, but when I replace things, I don't skimp and treat it all like a "tune up".

One thing to also check are the fittings themselves, even the metal one on the plenum. They could be clogged with crapola. My plenum had a coating of oily goo which I cleaned out and maybe this damaged the gooey hose and could have messed up the ac check valve at some point. Make sure the passage out of the plenum is clean as well as the other fittings. Canned air is your pal here.

I think I know more about the heating system of my car than anything else, which all things considered is pretty sad and strange seeing as I live in Fort Lauderdale and it's about 150 degrees outside now. We do use the heater for about a week out of the year though, lol. Course mine would be functioning even if I lived in a furnace 24/7. Eh, broken or bypassed parts REALLY bug me, lol.

I don't have a digital cam myself yet, but if you have any questions and have a camera, take some close ups(not TOO close, lol) of the various areas parts and I can point out anything you need info on.

 

its been raining like hell here, and its not going to stop until sunday. It stoped for like 5 minutes so i ran out to the car (car was warmed up real good i drove it for like 10 minutes ) and checked the hoses that go to the heater core. going to the valve the hoses are hot. The two hoses that go from the valve to the heater core are hot BUT only once they pass the valve. once the hoses reach the heater core they are no longer hot. THey are more like cool. I am hopeing that somewhere in the middle of those hoses they is some **** blocking it up. I have a feeling that my heater core is not getting the amount of water its suppose to.

 

Hey FIRBIRDNYC, I changed my radiator in the summer about a year ago and when winter came my heater did not work, well I change my thermo, didnt work, changed the heater diversion valve didnt work, changed the heater core didnt work but needed it anyway. Well felt like a real dummy but it was a stinking plug in my radiator heater line, just screwd it out and wooohoo, heat. The radiator mfg put covers over every other hole but forgot to take the plug out of that paticular connection, man what a pain in the butt. I would say just pull the hose and check it only takes about 2 min. GOOD LUCK.

 

hm wish i knew which plug your talking about . i have a v6 . Btw check my other post in the cooling section. i hate vacume problems

 

Follow the heater hoses to the radiator, then remove the hoses going to it, see if you have a plug in one or the other, it will be inside the fittings and will take a hex key to take out if its still in there. Good luck

 

i repeat i have a v6, there is no radiator hose that goes directly to the heater core. i know which hose you are talking about on a tpi but not for my monster . different setup. IM thinking about eliminating the valve