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Unread 12-02-2011, 07:26 PM   #16
Redfire03
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I have the same issues with my 5.9. I have checked the same things as you, and got the exact same results. I have also changed the thermo and coolant several times to try and get it warmer.

I have just learned to deal with the luke warm heat during the winter.

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Unread 12-02-2011, 07:48 PM   #17
zachjf
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Well I guess i'm gonna be the guinea pig on this deal and swap in a 210 thermostat as I'm not spending another winter freezing my *** off! That or I might figure out some higher temp fan switches and see if that makes a difference, as cold as its getting here, high 20's at nite, its miserable to drive.

Another thing is I think I may do is disable the broken factory heated seats or use the stock switches and get some of the newer style with carbon fiber elements and wire them up, as long as the input voltage is the same it should be a direct swap and it might be more bearable.
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Unread 12-02-2011, 10:36 PM   #18
Candymancan
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If we are all having issues with the heat in the 5.9's there has to be something else doing it. My guess and as someone mentioned to me in another thread is its sensor related. Maybe the temp sensors in the dash arent what they used to be or something ?

See i dont have an issue with heat, my heat can get so hot itll burn me. My problem is the heat comes and goes, its wierd.


I wouldnt put a 210f thermostat in there if i were you. These engines dont like running hot, why dont you just unplugg the low speed fan sensor and leave the high speed plugged in ? That will raise the vehicle temp up to what a 210f thermostat would.
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Unread 12-02-2011, 11:22 PM   #19
zachjf
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Quote:
Originally Posted by Candymancan View Post
If we are all having issues with the heat in the 5.9's there has to be something else doing it. My guess and as someone mentioned to me in another thread is its sensor related. Maybe the temp sensors in the dash arent what they used to be or something ?

See i dont have an issue with heat, my heat can get so hot itll burn me. My problem is the heat comes and goes, its wierd.


I wouldnt put a 210f thermostat in there if i were you. These engines dont like running hot, why dont you just unplugg the low speed fan sensor and leave the high speed plugged in ? That will raise the vehicle temp up to what a 210f thermostat would.
Candyman; mine does the same thing but I have to be sitting for a decent amount of time to make it happen, while driving its never above what the picture above shows, has to be sitting idle for a long time to actually hit 210.

As far as the 195 vs 205 I thought of that but a few people on the RAM forums have run the 205 degree thermo's in their 5.9's without issue and actually increased their gas mileage in the process, only by a few 10th's of an mpg, but I think I'm gonna try that first.

I did do a little testing with the thermo I took out, which was a standard Stant 195, against the Stant SuperStat 180 I had bought and noticed something slightly odd.... at the point the cheapo 195 stant was fully open, roughly 185 degrees water temp, the expensive SuperStat 180 was only half way open. Part of the issue may just be cheap POS thermostats. I have a 195 SuperStat on order but it wont be here till monday, after I swap in the SuperStat I'll post up my results.

As far as the fan switch goes, I also found 220 degree fan switches which may let the engine heat up to its optimal heat range before activating the fan. Either swap will be ok since 10degrees is far from causing a catastrophic failure and may fix, what seems to be, a 5.9 issue for those of us living in colder regions of the country.
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Unread 12-02-2011, 11:32 PM   #20
e30nate
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are you running a 50/50 coolant mixture, if its been getting colder, and you have more water than anti-freeze, it wont let it heat up as well as it should.
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Unread 12-02-2011, 11:41 PM   #21
zachjf
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its actually a little less than 50/50 at this point, more like 40% coolant, 60% water but there's has been no change either way because of it.
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Unread 12-03-2011, 12:21 AM   #22
ZJ5point2GCL
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Thats plenty enough water temp to have toasty heat, i bet your heater core is plugged.
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Unread 12-03-2011, 01:02 AM   #23
CatSplat
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Quote:
Originally Posted by ZJ5point2GCL View Post
Thats plenty enough water temp to have toasty heat, i bet your heater core is plugged.
I second that suggestion, heater core blockage of some kind. A good reverse core flush might do the trick for you.
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Unread 12-03-2011, 01:13 AM   #24
zachjf
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well, I'll give it a shot but the heater hoses get just as hot as the upper radiator hose, which isn't all that hot. TBH I'm thinkin about havin the radiator shop do an acid flush/refill on the whole system so I can at least cross that off the list as a possibility.
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Unread 12-03-2011, 05:21 AM   #25
jrayburn
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this is probably going to sound crazy but have you checked your water pump? I have a 4.0 that had no heat issues and would run hot at idle but temp fine driving. Again my jeep was running hot but no inside heat. I replaced the rad, therom, thermo housing and got the engine to stop over heating. Still no heat inside. The hoses were warm but not so hot that it would be bad to touch at rad and heater core. Thru me for a loop. The only thing I could think of was it wasn't circulating properly which made me think to check the pump. My rad hose didn't have pressure on it. When I pulled the water pump the flanges on the propeller were completely rusted away. Changed water pump problem solved.
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Unread 12-03-2011, 08:09 PM   #26
zachjf
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I actually havent checked the water pump, not really an easy way to do that without removing it but I'm not above going that route if need be.

This is my current plan of attack on fixing this;
1) Stant SuperStat thermostat to replace the cheapo
2) Stant HD radiator cap
3) acid flush of system and re-fill
4) water pump
5) 10 degree higher thermostat or 10 degree higher fan switch/or/disconnect stock low speed switch

Something has gotta be causing the cold running issue and I'm glad to know its not just me having it. For an engine that ran hot enough to require a vented hood from the factory you'd think this would be a non issue!
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Unread 12-07-2011, 06:04 PM   #27
jrayburn
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lol you'd think. . The water pump shouldn't be too hard. I'd check it just to make sure
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Unread 12-07-2011, 07:40 PM   #28
Candymancan
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Quote:
Originally Posted by CatSplat View Post
I second that suggestion, heater core blockage of some kind. A good reverse core flush might do the trick for you.

Yea thats what im thinking, not plugged up completetly but enough to cause fluctuations. Sadly i dont have a air compressor to push air through the hoses.

As for the waterpump, that isnt my issue as my pump is brand new, and even my old original one was fine as far as the properler thing inside.. I would be worried about one rusting tho... that doesnt sound good..
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Unread 12-07-2011, 07:48 PM   #29
KoreaZJ
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Heater core blockage? Blocked with what?
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Unread 12-07-2011, 08:05 PM   #30
phitmein
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Candyman you don't use air pressure you use a garden hose and run water threw it in both dirrections.

Becareful when removing the hoses because if you pull on them to hard you can break the heater core inlet or outlet pipe.

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