Thermostat questions

[TBSS]

isn't it heat that cuses mechanical breakdowns? if puttong a larger tranny cooler on your transmission increases tranny life, wouldnt it prove true that a cooler running engine would last longer? im not stating, iam asking because it seems to  make sense but i could be wrong!!!!!  Also why would youre mileage take a hit????

 

 

 

 

 

Korey

<{POST_SNAPBACK}>

So, following this line of thinking, if we could keep engine & tranny temps down to ambient (60-90 degrees), then this would be ideal, right?

 

The reason the answer is no is because there is an idea operating temp that is part of the design of the equipment....this is what the thermostat is designed to do - keep the engine and tranny at optimum, ideal, designed operating temps.

 

There was an article floating around talking about why 160 degree stats were bad...interesting article, don't know if anyone remembers where it is.

[TBSS]

The last article on this web page, entitled "Fan Control", says a few things about being too low on temps, and what the possible downsides are.

 

Still can't find the article I was looking for though....

[ytnova]

I used 190 as a general reference, knowing good and well this value is application specific. The pcm wants to get into closed loop asap, newer stuff is even in closed loop within minutes, yet alone seconds. Alot of people plug in scan tools and look at the enhanced side of a obdII vehicle and base there info off of that. That fact is you really need to look at the generic side also, especially things like mode$01-09 data. Most techs might really be suprised what values the pcm substitutes and what data the pcm receives, but actually ignores. The reality is the pcm's stratagy is to please and protect the cats while still being driver freindly. To answer your question, no I do not do reprogaming, but I do repair vehicles that people keep screwing up for a living. It seems alot of people are out there reprograming, that really don't understand how all of obdII vehicles work, yet alone what a new CANs vehicle is, or the statagy behind them. That is the reason I suggested going with some of the guys on here who program instead of a "one fits all hand held tuner."

[Holty]

well, thanks for all the replies folks. i'll be contacting pcmforless for a tune, but probably not wasting my time/money on the tstat. thanks.

 

btw, sorry for bringing this up again, i've searched and found numourous threads on it, but none of them are really too conclusive.

[tawss04]

i'm assuming you've never done any programming work. the pcm doesn't wait until 190º to go into closed loop. try again...

<{POST_SNAPBACK}>

Technology has allowed the pcm to go into closed loop earlier

 

Just for info- The only reason these engines and all engines run at these higher temps is to reduce tail pipe emissions and nothing else. Lowering the running temp a few degrees will not have any detrimental effects

[KoreySS]

So, following this line of thinking, if we could keep engine & tranny temps down to ambient (60-90 degrees), then this would be ideal, right?

 

The reason the answer is no is because there is an idea operating temp that is part of the design of the equipment....this is what the thermostat is designed to do - keep the engine and tranny at optimum, ideal, designed operating temps.

 

 

 

i undestand where you are coming from and toatally agree! however i did not mean ambient thats just rediculus! however is lowering it from 195 to 160 (35*) that much below operating temp to cause harm, i dont think so. but it is cool enough to improve performance. why do you think they dont sell a 75* t-stat? that would be too cold. 160* is a good operating temp

 

 

Korey

[TBSS]

So, following this line of thinking, if we could keep engine & tranny temps down to ambient (60-90 degrees), then this would be ideal, right?

 

The reason the answer is no is because there is an idea operating temp that is part of the design of the equipment....this is what the thermostat is designed to do - keep the engine and tranny at optimum, ideal, designed operating temps.

 

 

 

i undestand where you are coming from and toatally agree! however i did not mean ambient thats just rediculus!  however is lowering it from 195 to 160 (35*) that much below operating temp to cause harm, i dont think so. but it is cool enough to improve performance. why do you think they dont sell a 75* t-stat? that would be too cold. 160* is a good operating temp

 

 

    Korey

<{POST_SNAPBACK}>

Interesting comments earlier about emissions....is that really why engine and exhaust temps are what they are?

[zippy]

without going too much into detail on this endless discussion, the reason 192-195 is the most common selected thermostat temperature is simply heat. tailpipe emissions could be fixed at lower operating temperatures without a problem. engine crankase emissions on the other hand cannot. if you live in a very cold climate (when temps never make it above 32º) the moisture and other vapors never escape the oiling system. this leaves deposites, makes oil dirty quick, and causes oil contamination. the main issue is heaters. anytime gm has used a 180 stat in cars there are many complaints of poor heating in the cold months. engines such as the 2.4L DOHC, 6.6L Duramax, and 5.7L LT1 all use theremostats basing the operating temps at around 180. if you've ever ridden on one of these vehicles in single digit or colder weather you'll see why the 195 is chosen so often by the factory. that area of temperature also happens to be cool enough to not cause problems when you're in texas and it's 110º out. most of the info here is simply misinformation. on top of that there have been many articles written about why it's good or bad to run the cooler thermostat. more often than not this info is based on opinion by the writer and that writer gives facts and statements based on info he's read somewhere else...

[TBSS]

Okay, so let's say (just hypothetically) that I live in Southern California and don't use the heater but once or twice a year.

 

At what temperature would I need to operate my vehicle in order to be sure that the moisture makes its way out of my crankcase? Would I be alright with a 160* stat? Or a 170*? Which one would be ideal? Would I see an increase in performance? How much?

 

What about the gas mileage issue? Is it real?

[BenKey]

With the 160 stat, my engine only runs 10-12 degrees less than it did with the stock stat, although there is a 35* difference in their rating.

[vette dude]

isn't it heat that cuses mechanical breakdowns? if puttong a larger tranny cooler on your transmission increases tranny life, wouldnt it prove true that a cooler running engine would last longer? im not stating, iam asking because it seems to  make sense but i could be wrong!!!!!  Also why would youre mileage take a hit????

 

 

 

 

 

Korey

<{POST_SNAPBACK}>

So, following this line of thinking, if we could keep engine & tranny temps down to ambient (60-90 degrees), then this would be ideal, right?

 

The reason the answer is no is because there is an idea operating temp that is part of the design of the equipment....this is what the thermostat is designed to do - keep the engine and tranny at optimum, ideal, designed operating temps.

 

There was an article floating around talking about why 160 degree stats were bad...interesting article, don't know if anyone remembers where it is.

<{POST_SNAPBACK}>

No 60-90 degrees would not be ideal, at that point you would be exchanging so much heat through the cooling system that the engine would be putting out almost no mechanical energy.

I would like to see this article you are talking about.

[SS_bnoon_SS]

With the 160 stat, my engine only runs 10-12 degrees less than it did with the stock stat, although there is a 35* difference in their rating.

<{POST_SNAPBACK}>

 

That's because changing to a lower stat has nothing to do with overall cooling system efficiency. You need to change fan turn on temps to a lower setting in programming ('03-'04). If that's still not enough, you would need either larger CFM fans or a larger radiator in order to run nearer the stat opening temp.

 

Or it could just be you got a stat that's out of spec. I've purchased a 160 that didn't open until 175 degrees = factory defect, proven on a stove top with boiling water and a food thermometer. Took it back and got another one that opened at 163 = acceptable.

[BenKey]

With the 160 stat, my engine only runs 10-12 degrees less than it did with the stock stat, although there is a 35* difference in their rating.

<{POST_SNAPBACK}>

 

That's because changing to a lower stat has nothing to do with overall cooling system efficiency. You need to change fan turn on temps to a lower setting in programming ('03-'04). If that's still not enough, you would need either larger CFM fans or a larger radiator in order to run nearer the stat opening temp.

 

Or it could just be you got a stat that's out of spec. I've purchased a 160 that didn't open until 175 degrees = factory defect, proven on a stove top with boiling water and a food thermometer. Took it back and got another one that opened at 163 = acceptable.

<{POST_SNAPBACK}>

'03 or '04, doesn't matter, we don't have electric fans, nor is their ANY kind of setting in the PCM for them. Talk to me about '05, then you're talking, but that's not me. I have an '03 (Although I have added electric fans and they are controlled by the PCM - but that didn't change anything - they are set to turn on at 150, if you want to know - means they run always). I never considered a t-stat having anything to do with efficiency - that I would more relate to coolant type, pump rating, radiator type/size, fan, but not the t-stat. All it does is open up earlier, nothing more.

 

If my 160 stat is out of spec, then so is the stock one. Your truck will run hotter than 195, which is the stock temp. My motor actually runs exactly at 187, almost always. And, just because I'm reading that, doesn't necessarily mean my t-stat is operating out of spec. It all depends on where the temp is taken, but the t-stat could still be opening when it's supposed to, although I haven't checked on my stove. The dash gauge gets it's sampling from the driver's side head.

 

The big thing is using the gauge, it's not accurate. Close, but not accurate. I read mine from logging ECT, not reading my gauge.

[zippy]

most all 160 thermostats in a gen III small block run at 172-174º. this is the temperature i shoot for either way. with the exception of the possibility of setting codes P0125 and P0128, there is no reason not to run a cooler thermostat. (unless of course your average outside temperature is below 30º). there is no reason to consistantly run the engine at 195º and above.

[HOLSTEIN]

i cook on my stove