Heater blows cold air

Bengal313

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Before when I start up my car and turn on the heat, the heater starts blowing hot air in matter of few minutes. Now noticeably it take a lot longer to heat up. It blows cold air for a awhile before slowly warming up. Only thing I had done was have my antifreeze changed at my local oil change place.



Car: 2000 Lincoln LS VS 96,000 miles.
 
Probable has an air in the system; you need to bleed the system.

Try doing a search you should find out where the bleed screw is for your LS.
 
Go to TECH ARTICLES and under Lincoln LS read Draining the cooling system; there is a diagram.
 
It maybe the AUX pump, I had the same problem and after I replaced the pump, good as new.

But try this first....with the car running and the DUAC system off...hold the OFF and FLOOR buttons together for a few seconds and then press the AUTO button. This does a system check on the DUAC system. When completed everything on the display should be lit up and the numbers should read all 8s...if another number shows then that's your error code for you to get checked.

Also run the car at about 3000 rpm for about 5 min with the DUAC at full heat. Then turn off the car for about 10 sec then restart. This will purge any air you may have trapped in your heating core.

GL ;)
 
But try this first....with the car running and the DUAC system off...hold the OFF and FLOOR buttons together for a few seconds and then press the AUTO button. This does a system check on the DUAC system. When completed everything on the display should be lit up and the numbers should read all 8s...if another number shows then that's your error code for you to get checked.

I did this and the numbers read 88.8 on the left/driver side and -188.8 on the right/passenger side. Is this a faulty code?

FWIW while the DATC was counting down I could hear something in my dash opening and closing. It was making the noises when one first turns the a/c on and it can be heard under the dash.
 
I did this and the numbers read 88.8 on the left/driver side and -188.8 on the right/passenger side. Is this a faulty code?

You PASSED :D
The noises you heard were the solenoids (panels) opening and closing as it did the tests.

If you got a number like 24.4 183 would say something failed and take it to your nearest rip off....I mean dealership and get it looked after. ;)
 
I guess what I am trying to understand is. My heater was fine before I had my anti freeze change. I changed it because my car was reaching 100,000 miles and I thought it might be time. I heater was working fine before that. When I went to get my oil changed at the local 30 minute oil change place they said they could do it for $50. So I said go ahead. They used a contraption that sucked out the anti-freeze through the reservoir and then just refilled it. So what i am asking is that could changing the anti-freeze cause my heater to not work properly?
 
It maybe the AUX pump, I had the same problem and after I replaced the pump, good as new.



Also run the car at about 3000 rpm for about 5 min with the DUAC at full heat. Then turn off the car for about 10 sec then restart. This will purge any air you may have trapped in your heating core.

GL ;)

When I try to do this the following happens?

1. The car starts to shake as soon as I reach 3000 rmp. Is this normal?

2. I ran the engine just below 3000 rmp and it was fine (no shaking). The heat blows hot but as soon as I release it blows cold again. Also when I restart it blows cold air.

3. The code from the test are 88.8 and -188.8
 
What if my passenger side (all vents. including floor, dash, rear floor and vent) blow really hot air instead of set temp?
 
When I try to do this the following happens?

1. The car starts to shake as soon as I reach 3000 rmp. Is this normal?

Yes. The LS (at least all of the auto tranny LS's) have a built in rev limiter that limits you from revving past 3000rpm in neutral. Once it hits around 3000rpm, the computer shuts down fuel delivery, causing the shaking you experienced.
 
That is a relief. Okay after doing the heater test, which came out "passed" and after purging the air out by increasing the rpm for 5 minutes. My heater still blows cold air. I am thinking about taking it to the dealer and paying them $125 to flush out my heating/cooling system the right way. Should I do that or try something else? Am I waisting my money?
 
It maybe the AUX pump, I had the same problem and after I replaced the pump, good as new.

But try this first....with the car running and the DUAC system off...hold the OFF and FLOOR buttons together for a few seconds and then press the AUTO button. This does a system check on the DUAC system. When completed everything on the display should be lit up and the numbers should read all 8s...if another number shows then that's your error code for you to get checked.

Also run the car at about 3000 rpm for about 5 min with the DUAC at full heat. Then turn off the car for about 10 sec then restart. This will purge any air you may have trapped in your heating core.

GL ;)


Is there a similar diagnostic for the '03+ ?
 
It will be the same for all Ford products with the DUAC system for any year. :wrench
:I
 
I don't have a 'floor' button but a button that toggles between floor, vent, defrost and combos thereof.

Try holding off and different buttons for couple of seconds and the pressing auto or some other combination you can come up with.
It may work
 
That is a relief. Okay after doing the heater test, which came out "passed" and after purging the air out by increasing the rpm for 5 minutes. My heater still blows cold air. I am thinking about taking it to the dealer and paying them $125 to flush out my heating/cooling system the right way. Should I do that or try something else? Am I waisting my money?

A flush is not really needed at this age. I cant imagine any buildup of crud that would clog anything at this point. Im guessing you simply need a really good bleeding, which is simple if you follow the DIY on this site. It's all under the hood. No need to even get under the ground. You may need to flush 2-3 times to get every bit of air out of the system.

Also..are you 100% certain you arent leaking any coolant on the ground? If you have the V8, it would be dripping just behind the drivers side front wheel/wheelwell. That would indicate a cracked coolant reservoir. The craks often form at the bottom of the reservoir, and may not be visible from looking under the hood.
 
OK I've had the same problems heat when the long skinny pedal is pushed but none when at idle, I ran the little test and every thing came out right and I tried the bleed method but still no heat at idle well lukewarm(cool)?:confused: no leaks coolant is at level and no leaky heater core


I do think that there might be air in it some where b/c back in the summer I changed the breaks and I jacked one side up realy high and let it down then the other and I drove it 1/4 mile or so and the computer shut the car down b/c it got to hot I shut it off and let it cool then started it back the temp gauge went up like a rocket so I turned on my heat to try and make it back home and herd it bubble then the temp gauge dropped any ideas...
 
:confused: :mad: :confused: :mad: :confused: Ok what if I went to the tech articles and found the bleeding instructions, followed them step by step twice and bled and bled and lost the heater core bleeder and then cussed a lot, no but I did do it and at first it would blow hot air at an idle I drove it around no problems but then when I got home I ran the temp down to 75 and then back up to 90 and it never started blowing warm agian until I reved it then as soon as it idled back down it started blowing cool agian not cold but not warm either...:mad: :confused: :mad: :confused: :mad:
 
MaroonLS I think you may have to got to the cheatership and pay them to do a diagnostic :(

But sounds like you may need a new AUX pump....
 
Yeah I dont think so I have no intensions on doing that I would rather figure it out on my own:D I dont know Im just one of those guys,

I dont want to sound stupid but I guess its the only way to learn what exactly is the aux pump and what does it do?
 
I have the exact same problem with my 02 LS V8. Lukewarm at Idle, Hot while revving. I've done some 1-hour drives down the highway with no change, so I don't think I have air in my system. I was thinking that the waterpump was getting weak, so I was considering replacing it and the thermostat at the same time.

I would remote start the car, get in, and freeze my arse. Even though engine temp is half-way.

Also, my engine temp normally reads at exactly half, or just a hair above. Is that normal? (I'm used to little Japanese 4 cyl's that read just below half).
 
I have the exact same problem with my 02 LS V8. Lukewarm at Idle, Hot while revving. I've done some 1-hour drives down the highway with no change, so I don't think I have air in my system. I was thinking that the waterpump was getting weak, so I was considering replacing it and the thermostat at the same time.

I would remote start the car, get in, and freeze my arse. Even though engine temp is half-way.

Also, my engine temp normally reads at exactly half, or just a hair above. Is that normal? (I'm used to little Japanese 4 cyl's that read just below half).

mine reads exactly half too. and I still have the same problem as you guys... except mine never gets really hot.. it does get a tiny bit warmer when im moving rather than idling but no more than 5 deg. What I find odd is that even if I auto-start it for 10 minutes or so.. the initial blow of air i get out of it might as well be from the a/c, its freezing, then progresses to the sweet feel of luke warmness. boooo.. im going to the dealer cause im a lazy arse
 
mine reads exactly half too. and I still have the same problem as you guys... except mine never gets really hot.. it does get a tiny bit warmer when im moving rather than idling but no more than 5 deg. What I find odd is that even if I auto-start it for 10 minutes or so.. the initial blow of air i get out of it might as well be from the a/c, its freezing, then progresses to the sweet feel of luke warmness. boooo.. im going to the dealer cause im a lazy arse

Let me know how that turns out. It would help me a lot! I feel your pain on those cold days...and when the dealer invoice gets handed to you too.

Also, any idea how to program the dealer/factory installed remote starter to more than 5 minutes? Hoping to do it myself if I can avoid the dealer.
 
Yup. I haven't waited with a stop watch or anything like that, but it's nowhere near the standard ten minute mark. One morning I remote starting it then went and brushed my teeth. When I looked out the window after, it was running, then turned off as I watched. I don't know why the previous owner wanted it to only run for such a short time, but to each his own.
 

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