1998 1500 v8 5.9L thermostat change
#12
The 15 degree temp difference isn't really helping your engine run cooler..... Your computer is calibrated for the 195 degree stat. Going lower than that, the computer is adjusting mixture to try and convince the engine to fully warm up. (hence, the "too cold too long" codes that some folks experience) You are actually compromising the efficiency of your engine with the 180 degree stat. It might make a couple degree temp difference in intake air temps, but, any benefit from that is negligible.
Also, you state that it makes a big difference in under hood temps, but has no effect on heater performance? Do you not see the disconnect there? Most of your under hood heat comes from the exhaust manifolds in any event. They are a LOT warmer than 195 degrees.
So, unless you have a tuner that wants to take advantage of the lower temp thermostat, running the lower temp on an otherwise stock engine, isn't doing you any good at all. If you overheat on hot days, really working your engine, doesn't matter WHAT temp thermostat you have in there, it's still gonna overheat. That's a product of the cooling systems capability to dissipate the heat. Rate of heat transfer is directly proportional to the difference in temp...... a hotter radiator will shed heat faster, than a cooler one, given the same conditions. If you are generating more heat than the radiator can get rid of, thermostat temp ceases to be a part of the equation.
Also, you state that it makes a big difference in under hood temps, but has no effect on heater performance? Do you not see the disconnect there? Most of your under hood heat comes from the exhaust manifolds in any event. They are a LOT warmer than 195 degrees.
So, unless you have a tuner that wants to take advantage of the lower temp thermostat, running the lower temp on an otherwise stock engine, isn't doing you any good at all. If you overheat on hot days, really working your engine, doesn't matter WHAT temp thermostat you have in there, it's still gonna overheat. That's a product of the cooling systems capability to dissipate the heat. Rate of heat transfer is directly proportional to the difference in temp...... a hotter radiator will shed heat faster, than a cooler one, given the same conditions. If you are generating more heat than the radiator can get rid of, thermostat temp ceases to be a part of the equation.
I never said your cab/heater core maximum heat won't be affected with the 180, but all things considered it will still feel pretty hot, not scadling like the 195 hot is but it will make you sweat after 20 minutes in the cab and to me thats doing its job, warming you up!. This is only really a minor problem below 5 degrees and if you warm your truck up for a few minutes prior to going anywhere you don't even think about it. I can settle with heat a few degrees colder for those few days a year where its super cold. I did keep the 195 in my Neon, the truck does a lot of work and keeping temps of my Magnum lower was a big priority to me. Also your thermostat may be a 180 but temps can still range anywhere from 177-190 in different driving conditions even with the 180, I had my Laptop bluetooth OBD-2 scanner hooked up and that way I was able to monitor for fun all the different sensors and conditions. So while the 180 will keep is consistently cooler its not like it will prevent it from heating up completely either.
I have a 97 Ram with a 360, I have 12,000 miles on it since July when I put my 180 thermostat in, changed valve seals,changed plenum & did a tune up with one range colder 3923 Autolite Plugs and modded my throttle body. Zero problems, 16.7mpg average when I'm being nice to it and low end power galore with no off the line stumble like some 360s I've driven so I think that the 180 & the colder plugs make a difference even prior to modding my tb. It runs very strong and NO check engine light, if it was going to throw one it would have already in the 7 months I've had it since doing the above. I'm getting pretty much max advertised mpg with colder plugs and 180 thermostat and in previous threads I have people with 11-13mpg and 195 t-stats telling me I have efficiency issues lol.
OBD-2 parameters are that at 160 degrees is where the PCM enters Closed loop (considered warmed up), people using 160 thermostats are going to be the ones seeing any potential driveability issues, though I've heard of people on hot summer days removing them with no problems but who knows, I would trust that you would be boarderline starting to experience efficiency issues at 160.
Last edited by JoshSlash87; 02-11-2013 at 08:54 PM.
#13
Remove the alternator for improved access. This means also just loosening the 4 bolts on the A/C and the nut holding the frigerant lines. It is a biznitch to get the hose clamps on/off properly if you have to. Running extension for the socket to the tstat housing is a breeze.
I agree that not required to remove them though like Ham Bone said.
I agree that not required to remove them though like Ham Bone said.
#14
Actually Exhaust manifolds cool off relatively fast, even though they do reach the hottest temperatures on the vehicle. The thing that stays hot and affects performance is the aluminum keg manifold, because the engine radiates all its heat through it like a giant heat sink, or like stove top aluminum pan that conducts heat for cooking food. My exhaust manifolds have cooled to the touch longer before the keg intake ever has, even when I have a fan pointed at the engine prior to working on it, the keg will still be too hot to touch. The 180 thermostat has made a pretty noticeable difference in making that keg run cooler and not bake your face off when working on the engine when its hot or checking your oil.
#15
#16
Yes, it all helps by the coolant itself being cooler going through the keg in the coolant passages and by that cooling the iron heads & block down so less heat over all transfers through metal to metal contact (yes I know theres gaskets between the metal to metal contact zones described, but they don't curb the heat so it basically is metal to metal contact). The same physics as to why our plenum gaskets blow...aluminum likes to conduct heat energy. The keg is where a lot of that heat gathers & escapes and its a huge chunk of aluminum!.
Last edited by JoshSlash87; 02-11-2013 at 09:14 PM.
#17
Not so. As HeyYou stated, PCM will be working agaist it.....meaning running richer.
Absolutely true!
Then it would be helpful to state that it is your opinion. I only know of one person on the forum (there may be more that I am unaware of) that has any experience in the automotive industry. And his experience counters your opinion.
I am 100% with you on that!
The 15 degree temp difference isn't really helping your engine run cooler..... Your computer is calibrated for the 195 degree stat. Going lower than that, the computer is adjusting mixture to try and convince the engine to fully warm up. (hence, the "too cold too long" codes that some folks experience) You are actually compromising the efficiency of your engine with the 180 degree stat. It might make a couple degree temp difference in intake air temps, but, any benefit from that is negligible.
Also, you state that it makes a big difference in under hood temps, but has no effect on heater performance? Do you not see the disconnect there? Most of your under hood heat comes from the exhaust manifolds in any event. They are a LOT warmer than 195 degrees.
So, unless you have a tuner that wants to take advantage of the lower temp thermostat, running the lower temp on an otherwise stock engine, isn't doing you any good at all. If you overheat on hot days, really working your engine, doesn't matter WHAT temp thermostat you have in there, it's still gonna overheat. That's a product of the cooling systems capability to dissipate the heat. Rate of heat transfer is directly proportional to the difference in temp...... a hotter radiator will shed heat faster, than a cooler one, given the same conditions. If you are generating more heat than the radiator can get rid of, thermostat temp ceases to be a part of the equation.
Also, you state that it makes a big difference in under hood temps, but has no effect on heater performance? Do you not see the disconnect there? Most of your under hood heat comes from the exhaust manifolds in any event. They are a LOT warmer than 195 degrees.
So, unless you have a tuner that wants to take advantage of the lower temp thermostat, running the lower temp on an otherwise stock engine, isn't doing you any good at all. If you overheat on hot days, really working your engine, doesn't matter WHAT temp thermostat you have in there, it's still gonna overheat. That's a product of the cooling systems capability to dissipate the heat. Rate of heat transfer is directly proportional to the difference in temp...... a hotter radiator will shed heat faster, than a cooler one, given the same conditions. If you are generating more heat than the radiator can get rid of, thermostat temp ceases to be a part of the equation.
Absolutely true!
I am 100% with you on that!
#18
Anyone who wants to say the 180 degree thermostat sucks and that the 3923s suck can line their Ram up against mine and we'll compare stats of miles per gallon and performance and real world driving. The dyno information is there on Mopar Spead Tweaks, Mopar Action,Hot Rod Magazine and various websites dedicated to it and my odometer doesn't lie 12,000 miles without a code tripped and I have performance that can hang with a Hemi truck.
There are ways of mechanically fooling the computers or just the fact the computer doesn't care about certain parameters that run within its range. I ran 17psi of boost on my Neon for a year and a half by installing a check valve on the map sensor called a missing link, don't ya think if our PCM's were so freaking smart they would try to adjust for 17psi of pressure in a situation where vacuum is always supposed to be present? Why don't I run the turbo anymore? 17psi and 16 valves driving a Mitsubishi TE04h Turbo small turbo basically kills the turbo bearings and keeping the girl happy = money, so I sold the turbo kit I homemade!.
I agree with others that the cold air intakes and throttle body spacers are mental voodoo that doesn't work but looks great when you pop the hood, its dyno proven that its bs. I only promote things that I know others have dyno proven and I've tested to an extent. I find it offensive that people would go to the extent to say they would not trust somebody to work on their vehicle because they disagree with their opinion without having solid proof to back their own opinion up while holding others to a gold standard.
Plus if somebody knows an engineer who says certain things, you gotta remember not everything you hear is completely true even from them, sometimes they put out disinformation on purpose so that people do not bypass emissions or kill themselves racing. Lets not forget Chrysler Corp employees are the same ones who lied to us and the insurance companies and said the 426 Hemi put out only 425hp...yeah at 4400 Rpm 6000 Rpm was a different story! lol Its like that episode of mythbusters where they supposedly confirmed that the blood hounds that catch escaped convicts cannot be beat and that they will find their objective inmate each time, not true, that show on Discovery Channel (I almost Got Away With It) shows real stories of people who break out of jail fooling the blood hounds all the time and escaping to freedom.Point is they're not going to encourage you to beat a blood hound they want you to think you'd have no hope. There was a guy at a car show who said he worked for Chrysler and that the 426 Hemi only makes 350hp by todays net standards but theres countless videos of stock 426 Hemi cars on chassis dynos saying something very different....430hp to the wheels with a torqueflite trans! and net ratings measure Engine power with full engine accessories and NO trans. So the 430hp to the wheels kind of dismisses that supposed Chrysler workers opinion that I talked to years ago. For the record I still think Gross is a better way to measure power. But anyway thats another topic!
Last edited by JoshSlash87; 02-12-2013 at 03:45 AM.
#20
Some reading for the advocates of colder stats:
http://www.importtuner.com/tech/impp...ncrease_power/
http://www.tuneruniversity.com/blog/...the-advantage/
And then we have this article, which actually shows benefits from a colder stat. I would point out however, that the control system in this test includes a Knock sensor, and the computer tries to run as much advance as it can, and this is where they think the power gains came from. Our trucks don't have one, so we don't get that benefit.
Also, the keg absorbs FAR MORE heat from the rest of the engine, which is hotter than the coolant.... than it does from the coolant running thru the crossover at the front....
So basically, the conclusion I draw from these various tests, done on real world cars is, if you have a system that can dynamically alter spark advance with a knock sensor, giving the PCM the ability to know when it's "too much", a colder stat can help you pick up some power. Without it, it's pretty much a wash, and can actually decrease engine efficiency/longevity.
That is why Hemifever recommends a 180 stat with his tunes. He dials up the timing advance, to get more power from the engine.
http://www.importtuner.com/tech/impp...ncrease_power/
http://www.tuneruniversity.com/blog/...the-advantage/
And then we have this article, which actually shows benefits from a colder stat. I would point out however, that the control system in this test includes a Knock sensor, and the computer tries to run as much advance as it can, and this is where they think the power gains came from. Our trucks don't have one, so we don't get that benefit.
Also, the keg absorbs FAR MORE heat from the rest of the engine, which is hotter than the coolant.... than it does from the coolant running thru the crossover at the front....
So basically, the conclusion I draw from these various tests, done on real world cars is, if you have a system that can dynamically alter spark advance with a knock sensor, giving the PCM the ability to know when it's "too much", a colder stat can help you pick up some power. Without it, it's pretty much a wash, and can actually decrease engine efficiency/longevity.
That is why Hemifever recommends a 180 stat with his tunes. He dials up the timing advance, to get more power from the engine.