This is a continue thread.
https://dodgeforum.com/forum/2nd-gen...ml#post1908519
I pretty much hyjack the OP thread and wanted to continue in respect of OP.

From my searches it seems temps. at 165ish is normal for the 180 stat. From the info. for the Hypertech it says that the 180 stat. starts to open at 180 and should be fully open at 200, but does not cause the engine to run at 180.

IDK. Everything runs fine. My heat is there, temperature sensors is fine, fan clutch fine, gauge seems to be fine. The truck runs fine. BUT for some reason I got this ****ing gremlin in the back of my head telling me to put the 195 thermostat back in.

I guess my question is what is every ones normal temp with the 180?

****ing gremlin.

 

****ing gremlin.


with my old 195º stat, the temp would come up to the dead center between the mark above 130º and 210º and stay there, in 110º as well as 15º outside air temps.

my new 195º stat goes up to about 1/16" below the 210º mark then drops back down to the same dead center temp that it used to run.

when i first got my truck, before a new radiator and thermostat, it used to run about 1/16" below the 210º mark. how weird is that.
and i have good heat and don't ping. hmm...

 

LOL nice gremlin!

I been reading into it more, and it seem everyones temps are different in huge way. IDK why. Maybe everyone has gremlins too.

 

mines around 180 id say.....i had a problem with it "running hot", and i was thinkin that i was getting faulty tstats, changed a couple stats, changed radiator, waterpump was new,......turned out that the sensor was wrong....

 

If your running below 180º, you have a real problem and here's why. The ECU is programmed to go into closed loop mode when engine temp reaches 180º. It's counting on a timer to switch between what is called, open and closed loop mode. In order to switch to closed loop mode, there's two requirements that must be met in order to enter closed loop mode and one of those is that the engine temp must reach 180º. Even if all the other requirements are met and the timer reaches full time, it will never go into closed loop mode.

If your not familiar with those two modes, here's a general summary:

Open loop mode is used at time of engine warmup and is based on fixed parameter values. No monitoring of A/F mix is present. The two parameters that are used are the IAT and ECT. The ECT is the primary sensor that provides feedback to the ECU as well as the IAT.

In this mode, the O2 sensor inputs are not monitored. In this mode, the ECU is not in control of the A/F ratio. This is a rich running mode used for the sole purpose of starting the vehicle. IT's dumping more fuel at time of startup to get the vehicle started quick and keep it running.

Only after the engine reaches 180º and the timer has been met, can it switch over to closed loop mode. In this mode, the ECU now uses variable parameters based on sensor feedback from all your sensors - not just two. Plus, it also uses the CPS as well for aid in controlling your timing.

In order to find out if your truck is running cold, you must use a scan tool and note what the ECU says your temp is. IF it's at 180º your good to go but, if it is low- it needs to be removed and the OEM stock one put back in.

Depending on the year, it can be less or worse depending on where they set the temp limit parameter.

 

Very good info. much appreciated. I got a scan tool and will be checking it out. Here something just before you posted. I was out running today and keep a close eye on the temp gauge was the same 165ish. I figure I head home and remove my K&N air filter to sell on ebay and put my stock back on. Went for lunch and notice my temp. was floating around 170-180! Trunk even ran better? Weird. After reading your post it seem it coincides with the IAT, ECU, ect.

 

I believe the FSM states the engine must reach 147*F to enter closed loop, and it must reach that temperature by a preprogrammed time based on the coolant temp reading at start up, or the truck will throw a P code (usually P1281) for engine too cold too long

 

I was gonna say if it needs to reach 180 thats cutting it close for all us with the 180 stat.

 

Again, it depends on which ECU program you have. Some are set to different limits. Most average around 180ºF. This is why you find some that have no problems running a 160-T-Stat and some that do. That's the reason why. I believe that this can be addressed and resolved by using a DART or equivalent.

 

It is for some yes. Some have wider tolerances so, the temp doesn't have to be dead nuts. There's a percentage of people who have no issues and a smaller percentage that do not. Those who have the ECU programmed to a 140 range don't have issues running any T-stat including a 160 for that matter. However, there are some that have tried running a 160 T-stat and had received the error code. This again, is due to what the temp limit was set to.

The only way to really monitor this is to use some type of scan tool to see where it transitions from open to closed loop on each truck.