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2005 6.leaker little/no heat

1970Custom

They call me Spuds
14,107
447
Middleton, ID
So as the temps have been gradually falling, I've discovered that I lack anything close to acceptable heat output. At idle it's cold and while cruising it's lack luster at best.

The cooling system seems full, hoses are solid and reservoir is full. I'm Thinking either the control valve isn't working correctly or the heater core is plugged which leads me into more thinking that I'm not thrilled with...

Thoughts?
 

Austin

FTF's #1 Knob Polisher
10,350
297
Cumming, GA
EATC or manual controls?
 
probably a blend door issue.... a search will turn up enough info to read for days.
 
Nice heater no doubt. I particularly like the slide design but I'm on the fence with the grips. I've looked at them but never held one. Is it a shooter like most Sigs? In any case she's a find that's for certain. I'm sure you came out on the barter.


-rob3isme
 

1970Custom

They call me Spuds
14,107
447
Middleton, ID
Okay kids;

On auto it will put out heat, not a huge amount though; BUT, rarely does it go where I need it. If I hit defrost, it loses heat gradually but puts the air in the correct location.
 

Sparky83

Virginia Chapter member
5,566
219
Norlina NC
im with randy... the 6.0's are widely known for blend door issues... theyre operated off an both an electric motor and vacuum actuator..both sit behind the glove box and are easy to test... the other possibility would be the vacuum valve under the hood could be stuck not letting enough hot coolant to pass through.. if not eiither of those the vacuum pump sits on the pass side fender... beyond those id say youll end up having to check on your engine temps.. if its not getting warm there then you have thermostat issue...
 

CowboyBilly9Mile

Charter Member
7,118
442
USA
Okay kids;

On auto it will put out heat, not a huge amount though; BUT, rarely does it go where I need it. If I hit defrost, it loses heat gradually but puts the air in the correct location.

Bring me up to speed.......somewhere in here, didn't you mention you got a new ride and if so, I assume it's implied that it has EATC? And if yes, does it have a lot of miles?
 

CowboyBilly9Mile

Charter Member
7,118
442
USA
Okay kids;

On auto it will put out heat, not a huge amount though; BUT, rarely does it go where I need it. If I hit defrost, it loses heat gradually but puts the air in the correct location.

What caught my attention was the item made bold above. The previous rendition of EATC head unit, a single zone head unit, which is *probably* just cosmetically different than the superseeding model (single zone), was known to have a valving issue after lots of use (IMO, 181K would make it a candidate). Internally, there were, I believe, four sliding valves, piston in cyl style, electronically operated, and they have o-rings on them that degrade/fail with use, resulting in vac leakage and thus, issues with the air being directed to where it it desired. The fix for this is $99 on ebay or to troll the net, find the size of o-rings needed, replace them and use a light coat of silicone grease during reassembly. There used to be a youtube vid on how to replace those o-rings; if it's not still there I believe I downloaded it and can email it to you. You may even find someone selling a repair kit with those 0-orings on ebay.

Suggestion, with the above knowledge....a) troll the net a bit and see if this issue applies to your head unit and model b) If you have the vac operated on/off valve in one of your heater hoses, and when it's blowing cool/cold when it should be hot, see if that valve is open, partway open or closed. This, based on a vac leak on those o-rings. Food for thought and something easy to look into.
 
Last edited:

Sparky83

Virginia Chapter member
5,566
219
Norlina NC
So why heat on auto but as soon as I flip to defrost it gets cold? I can switch right back to auto and it'll warm back up?


theres a difference between vent heat and defrost settings. when its just on "heat" whether it be dash or floor or vents, your A/C pumps not running.. but when you switch to defrost your compressor kicks on.. was something they did to keep your compressor "active" in the winter so it wouldnt be locked up when you went to use it in the summer. If your blend doors are not operating fully the cold from the evaporator when the compressors running on defrost is counteracting the heat coming off the heater core.. also if your heater core is operating less efficient in comparative to the evaporator in addition to the blend doors the air charge would be cooled further than the amount of heat being exchanged in the air flow.
 

CowboyBilly9Mile

Charter Member
7,118
442
USA
Here Eric, should it get down to this:



*This is what guys on ebay are getting $100 + shipping to do. IMO, this vid deserves to be put up as a sticky.
 

CowboyBilly9Mile

Charter Member
7,118
442
USA
That is the valving inside the EATC head unit.
 

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