180 vs 190 thermostat ?

[HDR]

The recent heat we're having here has made me think about installing a 180 thermostat in my truck. My truck has 190 now and with a outside temperature above 100 degrees my ECT will get up to 200-205. Would 180 be better?

 

[Shadrach]

The engine is designed to run with a 190. If your rad and coolers are clean inside and out you shouldn't have any issues. Even bugs screens and mesh can make a difference. Of course more fuel added to the cylinders creates more heat. Shad

 

[JR]

^^^^ agreed. 190 is where theyre designed to run. As long as your cooling system is properly maintaind you wont have any issues. 205 is not overheating these engines.

 

[BIGNASTY]

Sons truck is a recent transplant from So Calif he ran a 180 when he lived in Redlands and had no problems running out to glamis in sand buggy season it worked out fine dont think people understand just how hot it can get there and Palm Springs/ Parker Dam boating ITS SMOKEING HOT NOW!!!!!

 

[rscurtis]

Changing to a 180 won't make any difference. If the indicated temperature 205*, the thermostat is wide open. The 180* stat will also be wide open at that temperature.

 

[BIGNASTY]

Changing to a 180 won't make any difference. If the indicated temperature 205*, the thermostat is wide open. The 180* stat will also be wide open at that temperature.

Just 10* sooner

 

[HDR]

So whats over heating?

 

[rscurtis]

Probably nothing. You're reaching the momentary limit of the cooling system. As the temperature of the coolant goes higher, the gradient with ambient will be larger, limiting any increase. Also, at some point, the fan will supply additional cooling.

 

[JLandry]

So whats over heating?

245 degrees.

With a 15psi radiator cap and a 50/50 mix of conventional coolant to water, the coolant mix won't boil until 265 degrees.

From the owner's manual:

13. Temperature Gauge

The temperature gauge indicates engine coolant temperature. Any reading within the normal range indicates that the cooling system is operating satisfactorily. The gauge needle will likely indicate a higher temperature when driving in hot weather, up mountain grades, in heavy traffic, or when towing a trailer. If the needle rises to the “245°F” mark, stop the vehicle, shift into N (Neutral), and increase the engine idle speed for 2 to 3 minutes. If the temperature reading does not return to normal, shut your engine OFF and allow it to cool. Seek authorized service immediately. See Cooling System information in the section on “Maintaining Your Vehicle. ”

NOTE: Engine idle speed will automatically increase to 1000 rpm at elevated coolant temperatures to improve engine cooling.

 

[HDR]

that makes me feel a whole lot better.

 

[Mark31]

JLandry, your comments reminded of my 440 cu in '74 D200 Dodge. To half way get along with that truck in hot weather, we drained the antifreeze and ran straight water with a can of Mac's #13 (water pump lube, rust inhibitor) from Napa. Although the boiling point for a mix is higher, it is easier to take the heat out of water than a 50/50 mix. I most certainly am not recommending this for a Cummins because I don't have a clue!! Mark

 

[rashwor]

I will stick my 0. 02 in here. My '05 came with the 190 stat in it. It has always run at 200 on the gauge when empty and about 205 - 210 loaded. Back in June, my water pump went out. Ahhh, the perfect time to change the stat to a 180 and put my new coolant in that I had been wanting to do!!!! The Karma!!



I put the 180 in and now it runs about 190 empty and still runs 205 - 210 loaded. My tow temps did not change. Also, I suspect that this winter the in cab heat will be less than what I would prefer... I may be going back to a 190 this winter. If I had it to do again, I would leave the 190 stat or replace with another 190 stat since it produced zero change on the loaded temps and those are the ones I specifically wanted to change.

 

[Blu-meanie]

I ran the 180° in my 2001 truck, for a short while. It was winter, noticable heater temperature difference. I changed it back to the 190°.
This is in Northern Commifornia, so those with "real" winters won't want to change it.

 

[MStaggs]

My truck sure has been running hot in this heat.
If I sit in a lot of traffic, the temp really starts to climb.
I was towing my trailer (12000#) the other day through the city and it started climbing way up to the point I had to turn the damn heater on to stop it from climbing any more.
It has been running a bit warmer since a recent re-build. I wonder if the reman injectors are putting more fuel in than before as EGT's seem higher also.

 

[rscurtis]

I once sat in summer traffic for 3 hours on the approach to the GW Bridge with my signature truck. The temperature would slowly creep up to about 210*. Turning on the AC, which would energize the fan, would bring it right down. I have no idea how long the truck would have to sit idling for the fan to be energized by coolant temperature alone.