I fully understand that sometimes trail-side repairs require a certain amount of MacGyvering. Gutting a T-stat or removing it completely in order to get off the side of the mountain is totally acceptable. However I don't see it as acceptable to do this on a daily basis
Not trying to say it is acceptable .... but the acceptability of longterm running without a t'stat .... is dependant on the weather and the length of time the engine will be running.
Since its hardly likely that those two criteria will always be suitable - every time the engine is started .... The thermostat levels the playing field by creating a constant minimum warm up temp. After its done its job and is fully open ... Its up to the cooling system to prevent problems.
But I'm reverting back to my original question, how does a 180* T-stat make a Jeep Cherokee run at 195* when almost everyone I have ever talked to says their XJ's run right around 210*?
1/. When ambients and windchill are cold enough to increase the radiator efficiency to its best potential.
2/. When the radiator is so big it "overcools" ...
for lack of a better word ... and the 180* thermostat is not fully opening ... because it has to restrict flow to keep the temp up.
The 4.0l typically runs at about 210* as per previous posts mentioning this ..... The 195* thermostat starts to open at 195* and is fully open at 210*
.... and a 1row radiator cools adequately enough to maintain a 210* temp in light load conditions ... in not too hot weather temps ... if all the cooling system components are in very good order.
The 2row rad is slightly better .... but neither are good enough to provide a low enough liquid temp at the rad outlet for a 180* t'stat to play with - to consistently provide an average 195* running temp ...
Theres a few fudge factors to consider ... ambients/windchill, ... cherokeekid88's post ... and even my own situation ....
2row copper/brass with a wider finspacing than stock radiators,
Stock type waterpump,
HD fanclutch,
195* t'stat,
10/90 coolant mix,
Separate tranny cooler ... and,
a little bit of venting happening at the rear corners of the hood ...
.... which provides me a constant ... 195* running temp all year round - give or take a few degrees on the coldest (30*) & hottest (110+*) days.
Yes its a 195* t'stat ... but I was lucky and it behaves like 188*/190* so the next one wll have to be a 190* or a bit less.
a little disclaimer ... No lift or big wheels ... or driving on the rev limiter
Pretty sure everyone here understands a thermostat only sets the minimum temp ... twas one of the reasons I posted that I reckoned this was a good thread.
Now how do we explain what Cherokeekid88 just said....
I really don't care how many people come on here and claim they replaced their thermostat with a 180* unit and they are running cooler than before. It's not because the thermostat is rated at 180*... It has to be because of some other overlooked factor.
Those factors would be weather for starters ... and then - changes from stock e.g.
Cherokeekid88 mentioned vents and waterwetter etc.,
... So he needs to list his exact, current setup ... and how it performs under heavier loads ... otherwise the newbs will think a 180* t'stat in a wornout, stock, 1row cooling system ... will perform miracles ...