Heating Problem - Plz Help!!!

[Rastlin]

I have a 2000 Lincon LS V6 w/ a manual 5speed tranny. I have this problem though - the AC runs fine and the cold air blows on the hottest days (in FL enviroment), however, for the past few weeks its been getting pretty cold outside (40s - 60s) and I have noticed that my heating is not working properly. The hot air will only blow when my engine is doing at least ~2700 RPMs ... so I've been driving on 3rd gear which cannot be good for the car. The best heating is when the RPMs reach 3000+ and the hotter air always blows from the passanger side and a little bit cooler air from the drivers side. Once the engine goes below ~2500 RPMs the air gets cold very fast (within a couple of seconds). I tried to look up forums with similar problems and could not find anything. If anyone knows what is causing this please let me know and possible ways to fix it. I'd rather try to fix it myself w/ someone's help before going for the service at the local dealership... I had a bad experience with them in the past when I took my car for them to fix it and know that they will charge me $80 just to look at it.
Thanks again!!!

 

[the_ancient]

have you checked the coolant level?

if it is low it will effect the flow through the heater core, at lower RPMs you will not have the proper flow.


Probally a long shot, but I always start with the easy stuff and move up from there.

 

[lsondubz]

Well when I am sitting at a dead stop in my 00 LS8 with the heat full blast it is blowing hard but when I go to accelerate the air really starts coming out, Ive been noticing too that when its on 90 it is warm air but not very hot like I would think...what can I do?

 

[Quik LS]

early LSes (and older cars in general) had an issue with their blender valves - meaning the mixing of cold/hot.

not hard to fix - but a real bear to get at as you have to pull most of the dash out.....

 

[the_ancient]

early LSes (and older cars in general) had an issue with their blender valves - meaning the mixing of cold/hot.

not hard to fix - but a real bear to get at as you have to pull most of the dash out.....

if that was the problem I dont see how RPM levels would effect the temp.


It has to be a Flow problem in the heater core for that, Meaning Bad stat, Clogged core, Weak Pump, or Low Coolant Level.... IMO

 

[Rastlin]

Re: heating problem

I did an oil change couple days ago and all of the fluids were fine (including coolant). I will check in the morning to make sure. Also, I never had a problem with an air coming fast (blower works fine). I am almost thinking that it could be a pump thats failing and thats why the hot air comes out only at higher RPMs but I never had a problem with the cooling. AC always blew cold air even on a 100 degrees days. Another thing that I was thinking of is thermostat which would explaing why the temperature coming out of the passanger vents is several degrees different than the air coming out of drivers side vents, but again, wouldnt it effect my cooling as well? and why would it only not give me heating at low RPMs? Is there a way to check a thermostat or how hard is it to get to it and replace it? Also, is there a seperate heating system in the LS? or is air being heated by flowing through the hot engine? Thanks again for all the replies!!!

 

[Rastlin]

Re: heating problem

I also want to add that I have noticed that the clutch on the AC compressor turns on and off kind of loud... I mean I can hear it from the inside, but its been like that ever since I got the car about 5months ago and since the AC - cold air - was working fine I assumed that its normal. Could the AC compressor have antything to do with my heating going bad?

 

[the_ancient]

I did an oil change couple days ago and all of the fluids were fine (including coolant). I will check in the morning to make sure. Also, I never had a problem with an air coming fast (blower works fine). I am almost thinking that it could be a pump thats failing and thats why the hot air comes out only at higher RPMs but I never had a problem with the cooling. AC always blew cold air even on a 100 degrees days. Another thing that I was thinking of is thermostat which would explaing why the temperature coming out of the passanger vents is several degrees different than the air coming out of drivers side vents, but again, wouldnt it effect my cooling as well? and why would it only not give me heating at low RPMs? Is there a way to check a thermostat or how hard is it to get to it and replace it? Also, is there a seperate heating system in the LS? or is air being heated by flowing through the hot engine? Thanks again for all the replies!!!

well a "crude" way, and kinda hard unless you have done it several times, is to wait until the engine heats up and feel the hoses for Flow.... but that will not tell you if it is the stat or the pump. Honestly though I doubt it is the pump.

You can also remove the Stat and put in in to hot water and see if it opens at the proper temp, but if you want that far just replace it, they are not that expensive anyway.

I dont know how hard they are to get on on the LS, never change mine on my LS.

as far as how the heat works, All cars have a heater core, which is more or less a small radiator, or heat exchanger, that the hot coolent flows through, this is what supplies the heat

Look for coolant hoses going in to the firewall, that is where your heater core is located.

 

[Rastlin]

Re: heating problem

I got mine to work!!! I checked the coolants levels in both tanks... the main tank (by the windshield) was a little bit low... filled it up and the hot air started to come out at low RPMs!!!! Thanks to all that posted threads with ideas!!!