Here is an interesting post by HankL, right here on dodge forum. Interesting read.

There are too many variables for me to be able to reverse engineer what I THINK is happening....... a couple degree temp change in the air from driving from full sunlight, to shaded forest will change O2 readings, and injector pulse width. In order to state FOR CERTAIN what the PCM thinks about engine temp, and how it reacts to it, I HAVE to be able to see the programming.

 

I've seen people say the 180 stat won't make the truck run any cooler. But others say with the 180 the heat won't work as well. If the truck doesn't run cooler with the 180, why would the heat in the cab be any different between 180 and 195 stats? Also, the stated reduced pinging with the 180...what would cause that? I assume a richer fuel mixture. Wouldn't the richer fuel mixture be caused by the PCM seeing cooler engine temps?

I'm not arguing that the 180 stat let's the truck run cooler...but it would appear to. I have a 195 and don't plan on changing it. Just curious how it doesn't run cooler. I mean I understand if its 90 degrees outside and you're pulling a trailer, the thermostat won't affect engine temps. But it seems like it would affect engine temps in most other circumstances where the cooling system isn't at the edge of its ability to keep the engine cool. Like I said, not arguing a point, maybe I'm missing something.

 

I installed the intake without a hitch yesterday and got almost everything hooked back up. I will finish up today and start her up. The only problem i had was i wrung off a intake plate bolt but i was able to drill into it and pull it out. Haha i just about had a heart attack when that happened.

 

Using your logic, if your 180º fails then you should replace it with a 160º.

Wow. Just wow. First of all, the pinging problems, when they happen, are due to the plenum gasket issue. The faulty Dodge work-around was a software update commonly referred to as "The Death Flash". Secondly, not every truck responds well to the Autolite 3923 spark plugs. There are plenty of threads here with varied reports on that. And as far as the plate issues -- yes, the aluminum plate makes a difference because aluminum and steel have different expansion rates when heated. Longer bolts have nothing to do with the equation. Again, in regards to a 180º thermostat

 

Uh no... and your grabbing at straws and trying to twist what I'm saying..... keep going with this though because your doing more for my credibility then your own....

BTW the expansion. And Contraction rates when it comes to this application, is so minuscule that they have no effect... every expert in metallurgy seems to agree it doesn't hold water here...the only real benefits are the fact that its thicker...for one it can provide even pressure to the gasket and you can use the longer bolts without the possibility of them bottoming out like they might on the factory setup...

 

With Your logic a magnesium AC VW block would never work since you've got steel cylinder walls against a magnesium block with no gasket...

 

I have Torque on my phone too, Augie, and I gotta tell you: it beats most of the paid for programs I have.. a matter of fact, the two best programs I have were both free..

you gotta tune to get the benefits of running a 180.. you can run a 180 w/o, but you're going to be gobbling down fuel..

the 195 IS for emissions.. pretty much period.. the EPA's concept is that the higher temperature burns excess gasses and runs cleaner, and at the cost of performance..

the 180 allows the engine to run cooler when it's not under heavy load.. the funny thing about it, though, is that your temperature is going to be more related to the health of your overall cooling system than what 'stat you use.. at some point, the 'stat is open- plain and simple- it's going to rely on the water pump's volume and velocity, the cooling surface/exchange, and the 'drag' of flow (or lack thereof) to maintain operating temperature.. If you're not asking much from the engine, the 180 flutters open and closed, and regulates the temperature.. if you're running WFO, the engine is going to achieve 180+, and from that point forward, it's all about the health and configuration of your entire cooling system..

the engine actually closes loop between 125* and 140*.. it doesn't need to achieve full operating temperature to close loop.. the 'stat is going to be what determines when the engine decides to circulate to maintain a temperature, that's pretty much all it does..

the coolant temperature element is going to sniff for temp (duh), compare it to intake temperatures (IAT), density (MAP), and adjust- before it settles on a trim (it never really settles, it's an ongoing process) it will use the o2's to reconcile it's actions.. it's a pretty cool process that i find pretty dang interesting..

I add this to say:

if your engine is closing loop at 140*, and the sensors are reading away as they are supposed to do, there is only one reason you're going to run rich with a 180 and one only- the PCM is EXPECTING 195 at some point.. When it doesn't achieve that, it dumps fuel to more positively ignite the load, and it maintains ignition timing under 15*.. when you PROGRAM for a 180*, it reduces the fuel because it KNOWS you're at operating temperature, and it KNOWS it can advance spark safely.. point is: if you DON'T program for the cooler 'stat, you're not reaping much benefit from running a cooler 'stat.. it will give the IMPRESSION of running better because it's running richer, and it won't ping simply because it's cooler and the PCM isn't advancing timing- but you're still not getting any gain from the 180 to speak of..

you DO if you program..

 

I want to agree, the cooling system being in proper working order will give plenty of heat into the cabin at operating temp. I had never flushed a heater core until I got my Ram. But then again I live in south Texas so AC is more of my concern.

 

ok, So when Torque is showing my timing change with the throttle and its well over 15degrees thats wrong? and if it runs richer shouldnt that be effecting my mileage? and my plugs are light tan?
my theory is maybe not all pcm's are so picky about temp beig exactly 195... afterall even 195 stats have a normal fluctuating range of +- 4 degrees right? if when under load my truck actually hits 185 degrees It could be in the safe zone for normal activity?
I guess this would explain why some get such bad mileage...if they only drive short distances the truck is never running at optimum conditions...especially in the winter..

 

double post