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Heater Problems - Need Help!

Old Jan 4, 2008 | 06:45 AM
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Heater Problems - Need Help!

This is my first diesel truck, so I am not familiar with a lot that goes on with this type of engine. My problem is when driving the truck with the heater on, it blows warm air as long as I have my foot on the accelerator, when I let off, the air goes cold. I would not believe this to be normal. Sitting in bumper to bumper traffic can get cold in the early morning rush hour. This site has been great answering all my questions so far. I can use your help again.

Thanks
Kirk

2003 F-250 7.3L Diesel 4x4 Single Cab
 
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Old Jan 4, 2008 | 06:50 AM
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Welcome to FTE.
Two things come to mind.
Clogged heater core. (Not as hard a job as you might think on the PSD.)
Thermostat stuck open and not allowing the engine to heat up.
It doesn't take much of a crack for that to happen.
 
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Old Jan 4, 2008 | 06:56 AM
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My truck actually had a t-stat that had a BUNCH of passage holes in it, from the manufacturer. Don't know who the manufacturer of the t-stat was but that darn truck was doing similar to what you describe. I'd start w/a 203 t-stat and don't forget a new housing. Made a HUGE difference in my truck.
 
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Old Jan 4, 2008 | 07:27 AM
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Thanks for the information, I will go check these things out. I'll let you know what I find out.
 
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Old Jan 4, 2008 | 07:31 AM
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Originally Posted by thundertex
Thanks for the information, I will go check these things out. I'll let you know what I find out.
If it ends up being a clogged heater core, remove the glove box and then you can remove the access panel for the heater core.
 
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Old Jan 4, 2008 | 07:40 AM
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This is so dumb I am almost reluctant to point it out. Being low on coolant can also cause this problem.
 
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Old Jan 4, 2008 | 09:02 PM
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I have the same problem just noticed it yesterday, now I know the reason why. I believe my T-stat might be my problem
 
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Old Jan 4, 2008 | 09:15 PM
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Originally Posted by Markadeck
This is so dumb I am almost reluctant to point it out. Being low on coolant can also cause this problem.
I don't think that's dumb. Sometimes I feel odd posting what seems like an obvious thing here because so many of you are much more knowledgable than me, but I've also read many posts where the obvious was past by and later pointed out and that's what ended up being the problem. I'd vote for restriction in the heater core. If it's the T-stat or you just end up changing it make sure put the T-stat in with the arrow pointing toward the back hole. I havn't changed to the 203 yet, because I'm not sure what the benefit would be.
 
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Old Jan 4, 2008 | 09:34 PM
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"I havn't changed to the 203 yet, because I'm not sure what the benefit would be."

Check out diesel site, they have wuite a good explanation of the 203 t-stat. I can tell you without a shadow of a doubt, my truck runs better, but my truck went from extremes, from never warming up, to the 203. When I bought the truck it had that crap t-sat in it that did not let the motor warm up, so I don't know what it would've run like with a 195 in it. But I can say that if I were to replace a 195, it would be with the 203.
 
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Old Jan 5, 2008 | 07:03 AM
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Originally Posted by Markadeck
This is so dumb I am almost reluctant to point it out. Being low on coolant can also cause this problem.
Yeah, let's not forget the obvious! Good post.
.
On the 203 'stat. I'm still on the fence on whether I want one myself. When I tow the trailer, the engine is working pretty hard and I would rather have a little extra cooling for the engine.
 
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Old Jan 5, 2008 | 09:18 AM
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Originally Posted by Kwikkordead
.
On the 203 'stat. I'm still on the fence on whether I want one myself. When I tow the trailer, the engine is working pretty hard and I would rather have a little extra cooling for the engine.
I'm with you Kwik,I don't think I want to start on the higher threashold of the heat the engine will withstand
I have always had more dificulty keeping an engine cool enough than warm enough,with the heat of the south I've found it quite easy to run temps 10 deg hotter than T-stat settings
 
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Old Jan 5, 2008 | 09:57 AM
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If you change you T-stat change the housing too. They are a piece of junk. A one time use only. I got the billet one and the 203 T-stat from diesel site and it works great.
 
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Old Jan 5, 2008 | 10:17 AM
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Kwik, My experiance with t-stats and cooling systems has been that the t-stat does not dictate how hot the truck runs, it controls minimum temp, but has no influence on max temp. ANother words, if your truck is running too hot, the temp of t-stat has no affect on that, there is another issue at hand. A 195 T-stat will open at 195, it's up to your cooling system to keep the truck down to 195.
 
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Old Jan 6, 2008 | 08:52 AM
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Originally Posted by TurtleRacing
Kwik, My experiance with t-stats and cooling systems has been that the t-stat does not dictate how hot the truck runs, it controls minimum temp, but has no influence on max temp. ANother words, if your truck is running too hot, the temp of t-stat has no affect on that, there is another issue at hand. A 195 T-stat will open at 195, it's up to your cooling system to keep the truck down to 195.
Same here.
But you should hear my radiator fan roar when I am pulling the trailer. The engine is definately getting hotter than 195!
I am more comforatable with that extra margin of cooling in the summer months.
For my VW Rabbit, I run the hottest thermostat available: 92c. Factory is 87c.
I would run the 203 in the truck if the trailer wasn't as big as it is
 
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