My truck is a 2003 4.7L gas engine. (Don't know if that makes a difference...) But certainly a fan would continue to blow for a good 30 secs. or so after switching off the iginition. But has I mentioned to Butch1581 (above), this seems to stop happening just at about the same time that the heating problem began. A complete flush is gonna have to happen for sure. (I just hope it's not the damn water pump...!)

 

Only an electric fan can be set up to run after the motor is shut off. The e-fan will not provide much cooling, since the water pump is not turning anymore. It'll cool the radiator. Cooling stops when the motor does -- has for a long time.

 

Bakerman I see location is Ukrane ? is the vehicle there? wondering what the pcm configuration is- look on emissions label if an export version things may be different,

the 180 t'stat will cause some issues - may set a code, consume more fuel, affect things such as timing, even shift points,

why lower t'stat anyway?

 

Never, ever had that issue. No code will be set, un-measurable amount of extra fuel will be burned over the coarse of an entire tank. The T-stat doesn't control timing. Engine temp does. Lower the t-stat 15* will have no effect on timing.
As far as shift points...Umm, that's the transmission. And again, the enigne is still fully warm at 180* so no shift points will be changed.
Maybe some of those would happen if you just ran w/out a t-stat, but not for just gettig a 15* cooler one.

Generally a lower temp t-stat would nee to paired with the on/off cycle of an electric fan to get maximum benefits if there is an e-fan??

 

Going to a 180* will have NO effect on timing. Will consume more fuel as it richens the A/F ratio slightly, but by a such a minute amount that you won't notice. Will NOT effect shift points (I'd like to know how you came up with that conclusion), and I've yet to see one throw a code...

 

the rational was:
temp has an affect on shift points- ck an OEM service manual...
I am not sure if ambient or ECT is read by PCM and shared over buss but mentioned it -

the code I was concerned w p0116 and thru p0119

" minute amount that you won't notice" fuel is $- the LTFT will notice.

there is also the "sludge" arguement as lower temps MAY not remove moisture... questionable to me ....

and what is gained... is the big question

need to be aware of these items especially when troubleshooting.

 

the ECT is a secondary temp source for trans controller (shift point) and the default if a trans sensor fails along with run time and something I forgot already...

althogh only 15deg ..... what is gained for all this change ?

 

I needed to richen my A/F ratio because after having a CAI and Tuner (set to performance which advanced timing), the addition of Long Tube Headers brought me out of spec on the lean side. Not CEL out, but close as read by my local performance shop. I was given three choices to correct this:

1) Custom Tune
2) Piggyback ECU or A/F controller
3) 180* Thermostat

The $25 thermostat brought me back well within specs, actually just a hair lean from stock factory specs.

If you've ever read my previous posts when the subject has come up, I DO NOT recommend a cooler thermostat for a bone stock truck. But if you have mods that work to lean out your A/F ratio, such as CAI and tuner, it is a good mod to balance out that ratio.

Even if you do your own work, as I do, it's never a bad idea to have a local shop check your settings and check your work....

 

Temp does control shift points, but that's when the engine is cold-warm. Shift points will not change from an engine that is 130* to one that is 210*. The only diff. is when the engine is cold-kinda warm. Ever notice your truck shifts harder in colder weather??? Yet it shifts the same when the truck is just getting warm to fully warm.

If fuel is $$$$ then you shouldn't own a V8. if your in need of a Big truck and are Fuel concious, then going easy on the throttle will save you gas. As Hammer said Miniscule diff. same as what I said, over a whole tank i would be surprised if you burned just 1cup more fuel. Now how much does that equate to? Well 1cup is .068 gallons. At $2.79 per gallon. That's a whopping 19cents. There's more difference in the amount that gas flusctuates than there is to be worried about the gas issue.

Sludge. It's not really sludge that the issue concerns. It is moisture. Sludge is from dirty oil, not moisture. ALl engines need to get above 170* to properly burn off inside engine moisture. This is where the guys who run 160* t-stats run into issue's, but then agian, most of those guys run only at the track. Anything above 170* is fine for even a stock engine. main reason behind the 195* stock t-stats are because of emissions.

What is gained.....Cooler engines produce more power. Now, how much is negligable???

As far as those codes go, driving very short distances all the time could even throw one of those codes. There's not enough diff from 195-180 to make any difference. Only difference would be the temperature difference that an electric fan would kick on vs when the t-stat would open. Not an issue on the Hemi's. The 4.7's i dunno. If they have an e-fan, then I suppose i could see a code popping up every now and again.