Im sorry, but it is kind of funny GM 21-NA-199

[Grumpy Bear]

2 hours ago, 16LT4 said:

 

Maybe maybe not, but heat soak is the best explanation I've come up with. 

 

A friend of mine reminds me when I observe a result I don't fully understand the reasons for to:

 

"Never argue with results".

 

Doing so won't change the result. 

[BlaineBug]

3 hours ago, 16LT4 said:

 

Maybe maybe not, but heat soak is the best explanation I've come up with.  Also, don't discount heat soak; if under-hood engine air can cost an engine 20-30 hp (based on fuel trims and trap speeds from engineer friends who log this sort of thing for fun), it will certainly help heat anything in the engine bay.  Even in sub-zero ambient temperatures, snow/ice melts off my insulated hood surfaces within a few miles/minutes, so heat-soak is definitely a factor.

 

Here's some information I obtained on another one of my vehicles to compare intake temperatures with and without the factory "cold air" intake snorkel installed, taking note of IAT (which is closely equivalent to engine-room air temp, of 100*F):

 

On the same loop, in the same direction every time, at the same range of speeds 30-65 mph. Some N52 E83 data from today:

Ambient air temp: 27.5*C

After 5 mile drive to get to operating temp as per ECT: IAT 29.5*C.

I stopped, removed the intake snorkel elbow from the air inlet to the air box. IAT shot up to 33.5*C within a few hundred yards. By the end of the loop, IAT hit a max of 38.2*C, dropping back to 37.2*C when I slowed down to a stop at the starting line.

Back to starting point. Re-installed the elbow. IAT dropped to 33.4 within 100ft, and ranged 31.5-33.5*C while driving.

Some interesting points. Regardless of whether the intake elbow was in place, idle temp after both loops was the same 36.5-37.5*C.

With the elbow OFF, 65 mph showed a 2*C WARMER IAT than at 35-40 mph. Under full throttle acceleration, where one wants power, IAT reached 39.5*C; if I sustained throttle position even longer, I would fully expect even hotter IAT.

With the elbow on, however, full throttle application saw the reverse. From 33*C at cruise at 45mph, I could instantly drop IAT to 29*C with my right foot, and then watch IAT more slowly raise back to its starting position once the throttle pedal was released. As long as I maintained the call for power with my right foot, IAT remained close to ambient air temp, unlike elbow off. Elbow On showed a smaller IAT temp delta at all speeds, only 2-3*C range compared to about 5*C, with the range occurring closer to ambient temp.

Elbow on IAT stayed within 10*C of ambient air temp at low-load conditions with only a 2*C delta at higher load conditions, while elbow off showed a minimum of 10*C and 12*C, respectively.

The divergent IAT data implies a few things: 1) under-hood airflow/air temp equalization is virtually nonexistent on this chassis and has no affect on IAT. If it did, IAT and vehicle velocity would have inverse relationships regardless of elbow installation. 2) further support that the factory air intake truly is a “cold air intake”, as lifting those valves higher and opening the throttle butterfly increase cold air velocity, combatting engine heat soak on the air intake tubes. The same speed-dependent elbow-on IAT data from above was replicated at a constant speed of 35 mph by downshifting into lower gears, increase engine RPM and intake air velocity, attempting to remove airflow as a variable.

 

I can agree on hot temperatures degrading performance when it comes to combustion air, but this is much different that heat transfer to aluminum lines flowing oil.  One reason why I've always stuck with factory air intake boxes.  Some cold air setups get it right but most don't, either sucking hot air from the engine compartment OR acting as a straw to suck up water, which I've seen happen.  Neighbor had a Mazda blow an engine in a flood as his "cold air intake" was mostly a K&N conical filter relocated closer to the asphalt pavement, D'oH!

Edited December 8, 2021 by BlaineBug

[mikeyk101]

So this topic got me thinking, which usually isn't very productive, but I digress... So previous generations did not use a trans thermostat or cooling lines. Transmission fluid stayed exclusively inside the transmission housing??? and therfore relied on cooling from fluid in the pan. That is unless an aftermarket trans cooler was added. So a factory trans cooler eventually got added but was temperature controlled as to allowing fluid to flow on earlier models to the radiator and later models to the condenser. So someone came along and was able to devise the "pill flip" mod which essentially allows fluid to constantly circulate instead of after reaching a certain temperature. This will obviously slow the fluid warm up as some of it is constantly flowing free from the heat of the transmission. I have seen elsewhere where trans fluid needs certain temperatures to allow proper shifting. But GM finally recognized that their initial 190⁰ thermostat is probably not correct and causing unintended consequences. So my pondering makes me wonder why not eliminate the trans fluid cooling system completely and go back to what they originally had unless you plan on doing some towing or carrying large payloads. If one was intending on using this as a daily driver, there really seems no need for the trans cooling. In my case, when towing the toyhauler, the cooling combined with the recently updated thermostat will be a good idea. But why offer trans cooling for cases where it would have never been really needed in the first place??? 

[Grumpy Bear]

4 hours ago, mikeyk101 said:

So this topic got me thinking, which usually isn't very productive, but I digress... So previous generations did not use a trans thermostat or cooling lines. Transmission fluid stayed exclusively inside the transmission housing??? 

 

Not quite. All automatic transmissions since the mid 1960's (GM) have had the ATF cooled via a cooler in the radiator tank. 2014 GM decided to use a thermostat to improve fuel economy.

 

From the 1960's until 2014 they cooled unregulated. Even my 64 Malibu SS Powerglide had a tank mounted trans cooler and no thermostat. So did all my TH350's, TH400s, 4T65E's and TH700R's. Every Ford I've ever owned going back to the FMX all had radiator tank coolers as well as did my AMC Torqueflite 727. 

[mikeyk101]

Good info, thank you @Grumpy Bear

[BlaineBug]

1 hour ago, Grumpy Bear said:

 

Not quite. All automatic transmissions since the mid 1960's (GM) have had the ATF cooled via a cooler in the radiator tank. 2014 GM decided to use a thermostat to improve fuel economy.

 

From the 1960's until 2014 they cooled unregulated. Even my 64 Malibu SS Powerglide had a tank mounted trans cooler and no thermostat. So did all my TH350's, TH400s, 4T65E's and TH700R's. Every Ford I've ever owned going back to the FMX all had radiator tank coolers as well as did my AMC Torqueflite 727. 

Ford has been using a radiator/condenser mounted transmission cooler thermostat with their 4R70W since at least 1998, likely among other models as well.  I can't speak to what the temperature of that thermostat was set to but I never recall hearing any issues with it or premature transmission failure, either.

Edited December 9, 2021 by BlaineBug

[Grumpy Bear]

2 hours ago, BlaineBug said:

Ford has been using a radiator/condenser mounted transmission cooler thermostat with their 4R70W since at least 1998, likely among other models as well.  I can't speak to what the temperature of that thermostat was set to but I never recall hearing any issues with it or premature transmission failure, either.

 

My newest Ford was right around 1998 (Mustang) and it a manual. A quick search shows Fords thermostat starts opening at 185 F, a few degrees lower than GM. Good to know. Thanks! 

[BlaineBug]

Here's a comparison to my last data involving transmission temperature with the original bypass/thermostat.

Today I was driving in city traffic at speeds no higher than 35-40 mph (average speed much lower of course) for about 2 hours with a couple of stops being made along the way.  Ambient outdoor temperature this time was lower by about 5 degrees, around 45 degrees.  Transmission temperature never rose higher than 151 degrees, and most commonly seemed to hover from 147-150.  That's an improvement of at least 40 degrees, and coincidentally, the temperature of the new and "revised" bypass/thermostat pill is labeled V135 while the old bypass/thermostat pill is labeled V180.  That's a difference of 45 degrees, so that's fairly equal to what I'm seeing.

Edited December 10, 2021 by BlaineBug

[16LT4]

On 12/8/2021 at 11:23 AM, BlaineBug said:

 

I can agree on hot temperatures degrading performance when it comes to combustion air, but this is much different that heat transfer to aluminum lines flowing oil.  One reason why I've always stuck with factory air intake boxes.  Some cold air setups get it right but most don't, either sucking hot air from the engine compartment OR acting as a straw to suck up water, which I've seen happen.  Neighbor had a Mazda blow an engine in a flood as his "cold air intake" was mostly a K&N conical filter relocated closer to the asphalt pavement, D'oH!

How the heating much different?  My entire house is heated quite comfortably by a small iron box kept at 450*F, by radiant and convective heat transfer.  If trapped engine heat under the hood was insignificant, the snow/ice on my hood in the winter wouldn't be melting off the hood within a few miles of driving, especially with the insulation material beneath the hood.  Hot air can't be both significant with regards to density-power yet insignificant to other parts found within that same space.

 

I popped the hood yesterday to take note of the routing of the ATF cooler lines: they are tucked in between the engine block and the starboard exhaust manifold, which gets to 300+*F within minutes.  One of my cars' sole method of producing cabin heat is by blowing air over the exhaust manifolds and then pumping that heat into the cabin, and I have HOT air out of the vents within less than a minute of starting the car, even in sub-0 ambient air temperatures.  So yes, simply flowing ATF past a heat source will heat because the tubes are being constantly heated.  Last I checked, the Sun does a pretty good job at heating the Earth entirely by radiant heat transfer. 

 

Note: I'm not discounting the effectiveness of GM's updated AT thermostat, simply stating that I've yet to see a single negative effect of flipping the pill in my application.

Edited December 10, 2021 by 16LT4

[dieselfan1]

On 11/22/2021 at 10:40 AM, dieselfan1 said:

We need some solid cold weather data here. 

I'm in Minnesota and it was 10°F here this morning.

On my lifted truck the pill is flipped and it got to around 117°F after a 10 minute warm up, 15 miles on a county road 50 mph 4th gear tow/haul on, and a couple miles 30 mph 2nd and 3rd gear.

I try to keep my R's around 1800-2000 rpm so it don't lug.

I'm afraid once it gets colder it ain't going above 100°. Especially on the highway. What do you think Grumpy???

 

Guys, please chime in with all your cold weather pill flipped data here....

More cold weather data....

My pill is flipped.

Two days ago it was -2° F.

15 minutes warm up.

20 miles at around 50 mph.

3rd and 4th gear only.

Tow/haul on like always.

Trans temp when I rolled out of my driveway was 48°. Temp on arrival was 102°.

After this I took a 75 mile run.

55 mph max. Never got above 111°.

Then i went another 110 miles with a few stops. Mostly around 10°-15° outside. Trans temp never got above 145°.

Now I'm wondering what happens when it's -15° to -20°???

Edited December 10, 2021 by dieselfan1

[Black02Silverado]

This is the temp of our 2016 Suburban with the new GM thermostat installed with a 90 mile and then stop and go the last 4 miles.  Outside temp was 55F.  On the interstate it was below just a little on the 150 mark.

 

 

[BlaineBug]

2 hours ago, 16LT4 said:

How the heating much different?  My entire house is heated quite comfortably by a small iron box kept at 450*F, by radiant and convective heat transfer.  If trapped engine heat under the hood was insignificant, the snow/ice on my hood in the winter wouldn't be melting off the hood within a few miles of driving, especially with the insulation material beneath the hood.  Hot air can't be both significant with regards to density-power yet insignificant to other parts found within that same space.

 

I popped the hood yesterday to take note of the routing of the ATF cooler lines: they are tucked in between the engine block and the starboard exhaust manifold, which gets to 300+*F within minutes.  One of my car's sole method of producing cabin heat is by blowing air over the exhaust manifolds and then pumping that heat into the cabin, and I have HOT air out of the vents within less than a minute of starting the car, even in sub-0 ambient air temperatures.  So yes, simply flowing ATF past a heat source will heat because the tubes are being constantly heated.  Last I checked, the Sun does a pretty good job at heating the Earth entirely by radiant heat transfer. 

 

Note: I'm not discounting the effectiveness of GM's updated AT thermostat, simply stating that I've yet to see a single negative effect of flipping the pill in my application.

I'm mentioning that the heat under the hoot has no significant impact on the aluminum trans cooler lines running through the engine compartment.  Also the lines are very low in the engine compartment and heat rises.  The baseboard heating radiators in your home are also much different as well.  If your radiators were just copper or brass pipes running around the room it would heat but not as well as having the fins on them to allow airflow to pickup the heat as it passed over them.  Also as you know the radiator covers of the old days as well as the sheet metal covers on more modern baseboard hydronic heating are also essential to help guide air over the heat exchanger.

[BlaineBug]

45 minutes ago, Black02Silverado said:

This is the temp of our 2016 Suburban with the new GM thermostat installed with a 90 mile and then stop and go the last 4 miles.  Outside temp was 55F.  On the interstate it was below just a little on the 150 mark.

 

 

Is there any way to cycle through the menu where the digital speedometer read out is to actually get a digital numeric readout for your trans temperature?  The Denali/Premier fully digital gauges are fancy but I can't see a precise reading.  I'm going to guess 155-160 "ish" for your trans temperature based on what that gauge shows.

[Black02Silverado]

2 hours ago, BlaineBug said:

Is there any way to cycle through the menu where the digital speedometer read out is to actually get a digital numeric readout for your trans temperature?  The Denali/Premier fully digital gauges are fancy but I can't see a precise reading.  I'm going to guess 155-160 "ish" for your trans temperature based on what that gauge shows.

No actual digital reading.  Just the gauge.  Now my Silverado has both which is nice.

[16LT4]

3 hours ago, BlaineBug said:

I'm mentioning that the heat under the hoot has no significant impact on the aluminum trans cooler lines running through the engine compartment.  Also the lines are very low in the engine compartment and heat rises.  The baseboard heating radiators in your home are also much different as well.  If your radiators were just copper or brass pipes running around the room it would heat but not as well as having the fins on them to allow airflow to pickup the heat as it passed over them.  Also as you know the radiator covers of the old days as well as the sheet metal covers on more modern baseboard hydronic heating are also essential to help guide air over the heat exchanger.

 

I don't have hydronic baseboard heaters in my house, and don't use the electric ones, and never said I did. 

 

I exclusively heat with a single hot, cast iron box, kept above 300*F from November through March by the ignition of cellulose.  It has no blowers, no fans, and no shrouding to direct heat flow.

 

The increased heating rate of the ATF flowing past the "hot boxes" now that it is allowed to flow past them is hypothetically why my ATF heats up faster.  Can you provide an alternative hypothesis to explain the data?

 

Heat rises, until it reaches the ceiling, and then heats downward.  The junction between the exhaust manifold and the engine block serves as a ceiling.  I 100% PROMISE you that if you were to lay under the truck, reach your hand up under the exhaust manifold, you WILL feel radiant heat from several inches away.  In the engine room of our ships, the exhausts (12" diamater schedule 80 pipe) are insulated with lagging 360*, not just on their tops, because while heat does rise, it also radiates out 360* from its source.  The radiant heat from aftermarket exhaust headers has been known to "cook" starters, which are often found beneath (or at least next to) them, hence one of the reasons for header wrap and mini-starters.

 

Dieselfan's data above with the pill flipped also shows a faster rate of ATF heating then my truck ever saw prior to flipping the pill, even in the 50s or 60*s F.

 

So, I'm happy with my quicker heating coupled with markedly reduced heat ceiling.