Interesting Oil Temp finding...

TyCorr

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I will add to that and say that hotter block/coolant temps lead to higher efficiency because you have less heat loss due to less temperature differential between the combustion chamber and the surrounding metal.

Ok but where people are drawing questions is once the stat opens the coolant is free to climb to whatever temp the ambient air and load dictate. I mean if a 180deg stat kept water or oil temps 20 deg cooler during a prolonged drive id be surprised. Ive never seen a difference. I changed water pumps and went to a cooler tstat last summer and my oil.still gets to.about 210 degrees once the truck is doing its thing.

Do yu have any ideas what effect 180 vs 200 deg water temp has on the temperature of a combustion.chamber or cylinder temps?
 

lincolnlocker

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I will add to that and say that hotter block/coolant temps lead to higher efficiency because you have less heat loss due to less temperature differential between the combustion chamber and the surrounding metal.

yes!! way better explanation of what i gave.

live life full throttle
 
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Ok but where people are drawing questions is once the stat opens the coolant is free to climb to whatever temp the ambient air and load dictate. I mean if a 180deg stat kept water or oil temps 20 deg cooler during a prolonged drive id be surprised. Ive never seen a difference. I changed water pumps and went to a cooler tstat last summer and my oil.still gets to.about 210 degrees once the truck is doing its thing.

Agreed. Cruising down the road unloaded in my truck and in the Texas heat, my oil temps range from 200-210* (at the hpop rez) depending on my speed and coolant runs around 204-212*.. Today cruising into work oil temp stayed between 202-205* and I was cruising at 70mph with ICP at 1400psi on flat ground. I've noticed if I change to a tune that keeps ICP lower while cruising, my oil temps drop 1-2*.
 

dirk0

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I don't know about the temp differential being an issue. Tuning will come into play at that point. The 180, 203, 205 stats will get to operating temp at the same rate. So if there is a loss of power due to thermal differences, play with the injector timing. No?

With a 20 degree difference, there isn't THAT much change in the thermal dynamics within the block. With the huge cooling system (and relatively small oil cooling system), the margins within the block are minimal. For those of us with big oil and injectors that move a lot of oil, the difference of 20 degrees makes quite a bit of difference.

I'd rather have sub 200 degree oil that isn't breaking down as fast. Can't really address oil sheer or aeration as much, but anything to help will work.
 

TyCorr

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I don't know about the temp differential being an issue. Tuning will come into play at that point. The 180, 203, 205 stats will get to operating temp at the same rate. So if there is a loss of power due to thermal differences, play with the injector timing. No?

With a 20 degree difference, there isn't THAT much change in the thermal dynamics within the block. With the huge cooling system (and relatively small oil cooling system), the margins within the block are minimal. For those of us with big oil and injectors that move a lot of oil, the difference of 20 degrees makes quite a bit of difference.

I'd rather have sub 200 degree oil that isn't breaking down as fast. Can't really address oil sheer or aeration as much, but anything to help will work.

Exactly with one clarifier: the 20.degrees was a hypothetical thermal change. I honestly dont.think oil is.going to stay below 200 deg F in hot weather without running more oil.coolers. Coolant ALWAYS exceeds 200 as well regardless of tstat. Once that mother opens the rating on the "thermal valve"(tstat) becomes about 90% irrelevant. At least in my findings. The water cooling system in these trucks is very nice as far as Im concerned and the oil drives the bus in this situation. If the.hpo gets up to 200ish, the water is gonna follow suit once the system is open and left to its own.
 

dirk0

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Exactly with one clarifier: the 20.degrees was a hypothetical thermal change. I honestly dont.think oil is.going to stay below 200 deg F in hot weather without running more oil.coolers. Coolant ALWAYS exceeds 200 as well regardless of tstat. Once that mother opens the rating on the "thermal valve"(tstat) becomes about 90% irrelevant. At least in my findings. The water cooling system in these trucks is very nice as far as Im concerned and the oil drives the bus in this situation. If the.hpo gets up to 200ish, the water is gonna follow suit once the system is open and left to its own.

As I posted before, I noticed 25-40 degree lower oil temps depending on the ambient temps\load in the back.

The radiator in these trucks shed heat like crazy. I learned that when a fan clutch decided to come apart right as I got to the house one afternoon. After using an air chisel to remove the damn thing, I drove the truck 20 miles to work in stop and go traffic as well as back home in the Texas summer heat. I couldn't run the A/C, but the truck never over heated. Trans temps were higher, but I had a 30k derale remote cooler with it's own fan, so it wasn't a big issue.

So..

If the tstat is full flowing at 180 degrees instead of 203-205, the radiator is already removing that heat fairly quick. Oil is able to stay cooler. Even trans temps are a slight bit lower.

Also, anything over 35-40mph, the fan isn't really doing anything unless you're pulling a lot of weight and it's hot out. Pulling a '35 TT, I only hear the fan kick in a few times on trips. The cooling system on a 7.3 is a beast.
 
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Oil temps on my truck dropped about 10* across the board when I switched to the 180* t-stat. I used to see 210-220 when I had the 203* t-stat and now im at 200-210. I'm happy with the temps I see now, I just wish I could get down to that 190 range while cruising.

Sent from my SAMSUNG-SGH-I337
 

TyCorr

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Oil temps on my truck dropped about 10* across the board when I switched to the 180* t-stat. I used to see 210-220 when I had the 203* t-stat and now im at 200-210. I'm happy with the temps I see now, I just wish I could get down to that 190 range while cruising.

Sent from my SAMSUNG-SGH-I337

And that is EXACTLY what id expect to see. I get that a thermostat opening at 180 is.moving full coolant quicker but its a three or four minute diference from 180 to 200+. Especially in the summertime.

Im not against tye 180 at all. On the.contrary I like it more than a 203. I was.simply.stating that I wouldnt expect.huge differences.

Dirk0- I agree that the 7.3 has an excellent cooling system. Capacity and capability are unmatched.
 

Lang

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Is there a thread on how the fan operates? Is it suppose to run continuously or...
 

lincolnlocker

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Is there a thread on how the fan operates? Is it suppose to run continuously or...

no it is not supposed to run continuously. it will sound like a 747 under the hood... i didnt even know mine worked till last summer working in kansas when it kicked on iw as like wtf is that....

live life full throttle
 

Gearhead

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Anybody every think about why it would be important to make sure the oil temp gets up to 215 or so minimum temperature? I'll give you a clue...... 212F is an important temperature.....
 

lincolnlocker

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boils moisture and other impurities out if the oil.. thats why alcohol burning cars usually have to change their oil way more often... it doesnt get hot enough..

live life full throttle
 

HVFC6040

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Didnt care when I was paying for it... If I wanted mileage I would get a Nissan Titan and rock the **** out of it getting 20-22 mpg.

Whoever told you titans get 20+ is either fos or completely clueless. Best I ever got was 17 from Nola to Austin and back. 99% of titans can't break past 18.

Titans get the worst mileage out of all mid size trucks.

Can someone explain the logic with lower temp tstats? To me it seems that just because the tstat opens at a lower temp it would still allow the engine to run at regular operating temp.
 

Barnhartal

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A 180 stat allows the coolant to start circulating around 175° instead of 195 with a 203. Therefore it takes more heat to get it up to operating temp. So yes eventually it will get up to the same temp. On a stock engine youd have to push it a lot harder for a lot longer. For those of us making more power were making more heat. So in theory we should get to operating temp about the same time as a stock truck with stock tstat.
If your putting around not asking for more power you'll probably never get to operating temp.
 

Cody

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Anybody every think about why it would be important to make sure the oil temp gets up to 215 or so minimum temperature? I'll give you a clue...... 212F is an important temperature.....

In for this answer..

I have a 180 t-stat, I'd love to hear what Matt has to say
 

lincolnlocker

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Anybody every think about why it would be important to make sure the oil temp gets up to 215 or so minimum temperature? I'll give you a clue...... 212F is an important temperature.....







boils moisture and other impurities out if the oil.. thats why alcohol burning cars usually have to change their oil way more often... it doesnt get hot enough..

live life full throttle







In for this answer..

I have a 180 t-stat, I'd love to hear what Matt has to say

i think my answer is correct.

live life full throttle
 

dirk0

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Meh.

Moisture is in the oil is going to be removed more over time than straight heat.

Being slung around pressurized, pressurized AGAIN, through the injectors and other areas of the engine for example, is breaking down the oil. Also, if I remember correctly.. fluids always keep an equilibrium of liquid and gas in a given space. Vapor pressure. The pressure is always constant, changing only with temperature. That being said, the fluctuation between ambient temp and oil temp will vaporize the moisture over the time you start the engine and drive. The vapor pressure (water\moisture\blow-by\whatever) is removed via the CCV. Oil doesn't "have" to reach 212*.

For oil to have "water\moisture burned off", it would have to really be in a pressurized environment.

Also, think about this. There are 2 vehicles. Exactly the same year, engine, trans, color, shape, everything! Except for the mileage.


  • Vehicle A: 30,000 miles. 10 years old. Only driven on occasion. Oil changed every 3,000 miles all routine mait. done properly.

  • Vehicle B: 130,000 miles. 10 years old. Driven everyday, 20-30 miles to work. Oil changed every 3,000 miles and all routine mait. done properly.
 

Lang

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Meh.

Moisture is in the oil is going to be removed more over time than straight heat.

Being slung around pressurized, pressurized AGAIN, through the injectors and other areas of the engine for example, is breaking down the oil. Also, if I remember correctly.. fluids always keep an equilibrium of liquid and gas in a given space. Vapor pressure. The pressure is always constant, changing only with temperature. That being said, the fluctuation between ambient temp and oil temp will vaporize the moisture over the time you start the engine and drive. The vapor pressure (water\moisture\blow-by\whatever) is removed via the CCV. Oil doesn't "have" to reach 212*.

For oil to have "water\moisture burned off", it would have to really be in a pressurized environment.

Also, think about this. There are 2 vehicles. Exactly the same year, engine, trans, color, shape, everything! Except for the mileage.


  • Vehicle A: 30,000 miles. 10 years old. Only driven on occasion. Oil changed every 3,000 miles all routine mait. done properly.

  • Vehicle B: 130,000 miles. 10 years old. Driven everyday, 20-30 miles to work. Oil changed every 3,000 miles and all routine mait. done properly.

Think about what...
 

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