So... I've been debating this since I put in a transmission oil cooler in 2013.
Do we skip the bottom section of radiator where ATF exchange heat with coolant?
I have it connected but it got me concerned since I discovered trace of oil floating on top of coolant in the reservoir. (Yes could be other things, but would like to eliminate possible point of breakage)
I'm not sure if the ATF pressure is helping keep coolant in, but I will remove it and see what happens. Either way bad rad's gotta go and it's not gonna take the trans with it(water contamination).
Never tried creating poll but here we go.
Oh if you could write your comment on why you chose to hook it up/bypass it, it would be great.
What the frick I went to answer the door and bathroom and now I can't post poll..... welp.... let's "post" our poll then.. thank you.
Quote:
Originally Posted by thoiboi
If you already put in an external cooler, then by all means bypass the Radiator lines. No singular point of failure sounds good to me
I agree. Also,, those screw-in hose clamps I used gets loose over time so I'm "supposed to" to check once in a while but thank you China they rusted the "STAINLESS"-stamped screw turning mechanism it's on there solid lol..
Also I used the B&M racing transmission cooler that works like a thermostat. Forgot how thick... will check this weekend probably.
I was under the impression it was a transmission fluid warmer for cold weather, either way I bypassed it entirely. The only downside is having to let the car warm up a bit longer, I can definitely notice a difference between driving shortly after starting the car vs. driving when the car is warm (in terms of how the shifts are performed). I usually let it warm up for 5 min, then take it easy the first 10 miles before doing any kind of spirited driving. (Edit: I never installed a transmission cooler, Type S comes with one stock).
Currently I have the holes plugged at the warmer (bottom of rad). Been thinking of getting a manual model radiator, as it does not have these fittings.
My recommendation is to keep the OEM Trans Cooler/Warmer, whatever you want to call it.
I am going off of my experience from a 700r4 or 4l60E. The Trans Cooler/Warmer is on the cold side of the radiator, not only does it bring the ATF up to temp faster, it also helps cool the trans fluid. Cruising in overdrive with the torque converter locked I see about 175 degrees, this is perfect. Towing a 4000lb trailer in 3rd (1:1) I see 185 to 210 degrees depending on ambient with a 195F thermo stat. If I run 185 degree Thermo, I can see the trans and engine temp shift down the 10 degrees.
A Water to ATF cooler is extremely efficient and packages well.
I would be curious to see what the TL Auto trans temps are while running.
I was under the impression it was a transmission fluid warmer for cold weather...
Highly unlikely. Why? By the time the radiator starts to warm up in cold weather, the transmission should have long since gotten up to operating temperature.
When I was installing mine, I referenced Type-S 5AT's plumbing so I put the "air cooler" after "water cooler". Thinking, car can now dissipate leftover heat after OEM "water cooler". In 2013-2014 I towed a loaded 6x12 single trailer over 3000 miles up and down WV was no problem. (But my 1-year-old side motor mount went so I got pissed and put 3 innovatives...) Changed fluid(3x3) once since then and tranny still shifts fine. I guess if it ain't broke don't fix it... Was concerend about slightly oily film floating on top of coolant in the reservoir.
Anyhow... so am I correct to assume, as long as I make sure the aftermarket cooler can cool more than OEM "water cooler", it's okay to bypass?
Highly unlikely. Why? By the time the radiator starts to warm up in cold weather, the transmission should have long since gotten up to operating temperature.
I mean, that's what you may think but that's now how it works. Radiator and coolant gets up to temp wayyyy faster than the trans fluid. A quick search of this website, Accord forums or even the Acura TSB's will confirm it is indeed an ATF warmer.
Why else would they design the transmission fluid to run through the bottom of the radiator when they already have a completely isolated and dedicated transmission fluid cooler present?
To warm the fluid up when the coolant is warmer than the trans fluid and to cool it down when the coolant is colder than the trans fluid.
Why else would they design the transmission fluid to run through the bottom of the radiator when they already have a completely isolated and dedicated transmission fluid cooler present?
To warm the fluid up when the coolant is warmer than the trans fluid and to cool it down when the coolant is colder than the trans fluid.
The point is, it is exceedingly unlikely the coolant will ever be warmer than the ATF. The only possible scenario I can come up with is if you start the car on a cold winter day and let it idle for maybe a half-hour, and even then I doubt the ATF will be cooler than the coolant.
On a cold start the coolant will ALWAYS reach operating temp before the trans fluid. How? Because the transmission only starts to dramatically warm up with operation, ie driving. Sure it warms slowly during idle, but not as fast as driving. After 5 min of idling I'm gonna wager that the coolant temp is much warmer than the transmission temp. They implemented this warmer function as a way to increase the rate the ATF gets to operating temp. Not sure why you're so insistent on arguing about something that has a documented function from the manufacturer. Especially when you don't even have an auto.
Coolant heats faster than trans fluid. I would agree the coolant assists in bringing the trans fluid up to a good operating temp quicker.
While the coolant in the engine may well heat faster than the ATF, the coolant in the radiator is another story entirely. On a cold winter day, the thermostat will only open to allow a trickle of coolant through with the engine running at idle, and that will mean, even after a half hour of idling the coolant in the radiator will be cooler than the ATF. If the vehicle is being driven during the warm up period (by far the best practice) then there is absolutely zero chance of the coolant in the radiator from ever being warmer than the ATF.
Hmm warming AND cooling ...... that makes me wanna not touch it ... yet I'm fiddling with several feet of 3/8" high pressure fuel line..... Both makes "sense" to me but if anyone has a definitive proof that would really help me make up my mind.
Come on folks, this is getting silly. If you don't believe me, and why the hell would you want to, this is the internet after all, just go out and measure the temperature of the coolant in the radiator, you'll find it is well below the temperature of the tranny at virtually all times. What I think is happening here is folks assume because the thermostat keeps the engine at 180°F this means that is also the temperature of the coolant in the radiator; no, not even close. Said another way, if the radiator coolant temperature was the same as what it is in the engine, then there wouldn't be any cooling and temperatures would spiral out of control quickly. To make this point even more compelling, I've measured radiator coolant temperatures of under 100°F on cold winter days; ain't no way that's going to help warm up the transmission.
I have a harbor freight infrared thermometer I got for fun...
Not sure if it can measure metal parts (description said, won't work on reflective surfaces)
but if anyone can suggest a way to get some kind of measurement with it, I'm all ears.
I suppose the warmup argument is valid enough. I'm just as concerned (probably more so actually) about any benefit the connection to the radiator might have during operation when fully warmed up. It seems based on what I've read, that most ATF's run around 175F - 200F during operation. The coolant is cooler than that, especially by the time it gets to the bottom of the radiator (hot coolant comes in the top, cooled is sent back to the engine from the bottom, which is where the ATF cooler portion flows though) , so it seems that it would have a cooling effect by running the ATF though the "cooler" in the radiator. Cooler ATF is a good thing obviously. Mind you, not cold, but cooler during operation. Based on that, I've left mine alone.
For ~$100 you can get a B&M cooler that would be sufficient in replacing the ATF cooler in the bottom of the radiator. I've heard several times of the radiator failing internally and allowing trans fluid and coolant to mix.
Modern vehicles use an in-radiator transmission cooler for several reasons:
cost - a fluid to fluid cooler of the type used (it’s just a little plate cooler in one radiator end-tank) doesn’t need to be anywhere near as big as an air to fluid cooler, which reduces the size and therefore cost of the cooler. It’s also protected from corrosion caused by road debris and salt, so it lasts longer, weighs less resulting in lower vehicle weight and higher fuel economy, and simplifies vehicle assembly.
fuel economy - the trans cooler being installed inside the engine cooling system results in the transmission fluid reaching operating temperatures sooner, which reduces power wasted in the transmission during warmup. Essentially, waste heat from the engine cooling system is used to warm the fluid instead of wasting still more energy churning the more-viscous cold transmission fluid within the transmission to heat it.
except under extreme towing conditions, it keeps the transmission fluid at approximately the same temperature as the coolant, resulting in a more predictable transmission fluid temperature than if the cooler was separate.
Modern vehicles use an in-radiator transmission cooler for several reasons:
cost - a fluid to fluid cooler of the type used (it’s just a little plate cooler in one radiator end-tank) doesn’t need to be anywhere near as big as an air to fluid cooler, which reduces the size and therefore cost of the cooler. It’s also protected from corrosion caused by road debris and salt, so it lasts longer, weighs less resulting in lower vehicle weight and higher fuel economy, and simplifies vehicle assembly.
fuel economy - the trans cooler being installed inside the engine cooling system results in the transmission fluid reaching operating temperatures sooner, which reduces power wasted in the transmission during warmup. Essentially, waste heat from the engine cooling system is used to warm the fluid instead of wasting still more energy churning the more-viscous cold transmission fluid within the transmission to heat it.
except under extreme towing conditions, it keeps the transmission fluid at approximately the same temperature as the coolant, resulting in a more predictable transmission fluid temperature than if the cooler was separate.
I agree with points one and three, your second point is untrue. There is absolutely zero warming effect of the ATF gained from the coolant. Why? Because the coolant is virtually always cooler than the ATF.
I agree with points one and three, your second point is untrue. There is absolutely zero warming effect of the ATF gained from the coolant. Why? Because the coolant is virtually always cooler than the ATF.
I don't know... It sounds purely coincidental that it may happen and fluid dynamics would dictate that it MAY happen, but it's hard to say that it's designed to happen that way.
Our cooling system work such that the warm coolant is coming from the engine via the top hose and cooled coolant is going into the engine block via the bottom hose, or is is vice versa? I think any warming of the ATF via the radiator is neglible
I don't know... It sounds purely coincidental that it may happen and fluid dynamics would dictate that it MAY happen, but it's hard to say that it's designed to happen that way.
Our cooling system work such that the warm coolant is coming from the engine via the top hose and cooled coolant is going into the engine block via the bottom hose, or is is vice versa? I think any warming of the ATF via the radiator is neglible
Yes, the hot coolant exits the engine and enters the radiator at the top. The coolant works its way down through the radiator, gets cool(er), and then goes back into the engine via the water pump.
Yes, the hot coolant exits the engine and enters the radiator at the top. The coolant works its way down through the radiator, gets cool(er), and then goes back into the engine via the water pump.
If that's the case, by the time the coolant hits the ATF lines, it'll be "cool" and nowhere near "Operating temperature"..
For ~$100 you can get a B&M cooler that would be sufficient in replacing the ATF cooler in the bottom of the radiator. I've heard several times of the radiator failing internally and allowing trans fluid and coolant to mix.
I already have the B&M cooler after OEM water cooler. It has been great for the past ~6 years. I guess now the question is if OEM water cooler provides any benefit as to being a "heater" occasionally or keeping the temperature stable as opposed to the B&M cooler cooling it as much as it can.
I already have the B&M cooler after OEM water cooler. It has been great for the past ~6 years. I guess now the question is if OEM water cooler provides any benefit as to being a "heater" occasionally or keeping the temperature stable as opposed to the B&M cooler cooling it as much as it can.
Keep it, it's there to keep the ATF fluid at the optimal temperature which extends it's life and change interval
Quote:
Originally Posted by horseshoez
Name me even one scenario where the heat in the lower radiator will be 160°F and the ATF will only be 100°F. I don't think you can.
Your transmissions real source of heat generation is from slipping of the torque converter when it's not locked you are taking mechanical energy and generating heat in the ATF fluid. When the TC is locked cruising at steady state there is minimal thermal input to the ATF fluid. Why do you think OEM's tell you to check the ATF fluid level after it has been driven for over 20 to 30 minutes?
Maybe this will help you regarding temps in the radiator?
Heat Load to the Cooling System
The heat load to the cooling system is related to the flow through the radiator and the temperature drop through the radiator by the following expression:
Q = M * cp *dT
Where Q is the heat load BTU/min.
M is the mass flow rate of the coolant in BTU per pound per degree F
dT is the temperature drop through the radiator in degrees F, and * indicates multiplication.
Since a gallon of coolant weighs about 8.3 pounds, we can replace M in the expression by 8.3 times the coolant flow in gallons per minute, or GPM.
The resulting expression is as follows: Q = 8.3 * GPM * cp * dT
Since the specific heat of the coolant is essentially constant and the coolant flow rate is constant at rated engine speed, the expression tells us something that surprises most people. That is, for a given heat load and coolant flow rate, the coolant temperature drop through the radiator will be constant, and nothing anyone can do to the design of the radiator can change that. Adding rows or fins or face area or whatever will not change the temperature drop through the radiator. As a general rule, cooling systems are designed to operate with a coolant temperature of about 190 degrees F at the radiator inlet and have about a 10 degree F temperature drop through the radiator at rated power and rated coolant flow. This will result in a bottom tank temperature of 180 degrees F.
A cooling system whose heat load and coolant flow rate results in a 10 degree F coolant temperature drop through the radiator will have that same coolant temperature drop whether the radiator has a very small face area and flat fins or a very large face area and louvered fins. The difference is that the large louvered fin radiator will be more effective than the small radiator at transferring heat to the cooling air, meaning that it can do it with a much lower difference in temperature between the core and cooling air. The small radiator may require such a high difference in temperature between the core and the cooling air and the core that the coolant may reach boiling temperature before the core is able to transfer all of the heat load to the cooling air. While both radiators would have the same coolant temperature drop through the radiator, we would say that the larger radiator had better heat transfer performance if its top tank temperature (Inlet coolant temperature) stabilized at, say, 180 degrees F while the smaller radiator stabilized at 220 degrees F.
TL;DR: A general rule, cooling systems are designed to operate with a coolant temperature of about 190 degrees F at the radiator inlet and have about a 10 degree F temperature drop through the radiator at rated power and rated coolant flow. This will result in a bottom tank temperature of 180 degrees F.
There seems to be some misunderstanding regarding the content of the article you referenced; that as well as how automatic transmissions work and make heat. First about that last point, it actually surprised me when you said:
Your transmissions real source of heat generation is from slipping of the torque converter when it's not locked you are taking mechanical energy and generating heat in the ATF fluid. When the TC is locked cruising at steady state there is minimal thermal input to the ATF fluid.
Why was I surprised? Because your user name seems to indicate you drive a car with a manual transmission, and by your logic, manual transmissions won't get warm. The thing is, automatic transmissions make heat, a pretty fair amount of it, at ALL TIMES, even when sitting in Park or Neutral for extended periods of time.
Now to the article, it is addressing a situation where an engine rated at 200 HP is run constantly at full power and has a 190°F top tank temperature and a 180°F bottom tank temperature with an average core temperature of 185°F. With this in mind, I have several points:
If the example engine is run at a constant 200 HP, then the temperature of the transmission will be well into the 200°F zone, regardless of whether the torque converter is locked or not. Result: The ATF is significantly hotter than the coolant.
If the example engine is run at steady state freeway speeds, the engine constant output would be, depending upon the car, somewhere in the 20-40 HP range, and the heat coming out of the transmission will be proportionally lower as well. Using the sample 100°F day used in the article, I would expect the average core temperature to be more in the 150°F range while the ATF may drop as low as the 190°F range. Result, the coolant will be much cooler than the ATF.
Then there will be days where the OAT is much lower than 100°F, this too will drop the average core temperature, and by extension the ATF temperature, but never will the ATF get cooler than the coolant.
Meh I have a Van with a 700r4 or an non electrically operated 4L60E , it's my tow vehicle. I installed a trans temp gauge. It has a transmission heat exchanger in the radiator for oil and ATF as part of a HD tow package. It also has a locking TC.
Towing:
Thermostat 195f
ECT 210F
Trans Temp: 175F-185F
AC on
ECT 215F
Trans Temp 185F-195F
Thermostat:185F
ECT: 200F
Trans Temp:165F-175F
Stopped in Traffic:
ECT Temp: 210F
Trans Temp: 210F
Not Towing:
Thermostat 195F
ECT: 200F
Trans Temp:165F
Trans Temp Desired to extend life 175F, GM calls out changing ATF 10,000mi to 20,000mi if used for towing or used as a taxi (stop and go)
Oil Temp is usually 10-20 degrees warmer than ECT.
Engine is around 190F to 200F
I have an engine oil to coolant heat exchanger on my Integra ( found on OBD1 B18C1 and Integra Type R's) oil temps gauge on it (track car) and it dramatically reduces the oil warm up time.
OP, I would keep the OEM heat exchanger hooked up prior to the B&M cooler, unless you have a thermostat for the aftermarket ATF cooler if this a street driven car.
Meh I have a Van with a 700r4 or an non electrically operated 4L60E , it's my tow vehicle. I installed a trans temp gauge. It has a transmission heat exchanger in the radiator for oil and ATF as part of a HD tow package. It also has a locking TC.
Towing:
Thermostat 195f
ECT 210F
Trans Temp: 175F-185F
AC on
ECT 215F
Trans Temp 185F-195F
Thermostat:185F
ECT: 200F
Trans Temp:165F-175F
Stopped in Traffic:
ECT Temp: 210F
Trans Temp: 210F
Not Towing:
Thermostat 195F
ECT: 200F
Trans Temp:165F
Trans Temp Desired to extend life 175F, GM calls out changing ATF 10,000mi to 20,000mi if used for towing or used as a taxi (stop and go)
Oil Temp is usually 10-20 degrees warmer than ECT.
Engine is around 190F to 200F
I have an engine oil to coolant heat exchanger on my Integra ( found on OBD1 B18C1 and Integra Type R's) oil temps gauge on it (track car) and it dramatically reduces the oil warm up time.
Can you measure Trans Temp, ECT temp on start up too and then a few minutes after starting up too?
OP, I would keep the OEM heat exchanger hooked up prior to the B&M cooler, unless you have a thermostat for the aftermarket ATF cooler if this a street driven car.
Sorry, not sure how I missed this thread.
While interesting, the numbers presented are not terribly valid for this discussion. Two things, we're talking about 3G TLs here not large towing vehicles, and second, without OAT and average core radiator temperatures, the numbers are effectively meaningless.
Can you measure Trans Temp, ECT temp on start up too and then a few minutes after starting up too?
The ECT always beats the trans temp at coming up to temp. My trans temp starts reading at 100F, it takes 20 to 30 minutes to get the trans up to temp, long after the engine is warmed up.
Quote:
Originally Posted by horseshoez
Sorry, not sure how I missed this thread.
While interesting, the numbers presented are not terribly valid for this discussion. Two things, we're talking about 3G TLs here not large towing vehicles, and second, without OAT and average core radiator temperatures, the numbers are effectively meaningless.
Towing is considered severe duty, thus generating a greater amount of heat in the transmission. Although it's not the same auto transmission let alone size of vehicle, the Auto trans operates the same, however the TL is much more controlled. It has loads of inputs compared to mine that uses a throttle position cable to know what the demand is.
Why I mention it, what requires more energy moving a TL or Towing 4000lbs? Which generates more heat in the trans ? The numbers above show it and show they ATF operates at lower temps while not towing, or normal use.
With more modern automatic transmissions against the example I gave you (700r4) the TL is leaps and bounds better as far as efficiency and design.
Crack open the service manual and note the TL PCM is using the following to control how the transmission operates.
Engine RPM
TPS Sensor Signal
ECT Sensor Signal
Barometric Pressure signal
MAP sensor Signal
ATF TEMPERATURE SIGNAL
Consider the J32 uses an integrated exhaust manifold surrounded by coolant, this reduces warm up time, reducing warm up time reduces emissions by allowing the engine to operate in the window that generates the least amount of emissions.
The whole name of the game is to get the engine and trans within their optimal operating temp windows as fast as possible which reduces emissions and maximizes fuel economy. <- The point you disagreed about.
The ECT always beats the trans temp at coming up to temp. My trans temp starts reading at 100F, it takes 20 to 30 minutes to get the trans up to temp, long after the engine is warmed up.
The thing you're missing here is just because the engine is warmed up, that in no way means the radiator has achieved it's peak run-time average core temperature. Said another way, after only 20-30 minutes, the radiator is still well below the coolant temperature in the engine.
Quote:
Originally Posted by 6spd-GERCO
Towing is considered severe duty, thus generating a greater amount of heat in the transmission. Although it's not the same auto transmission let alone size of vehicle, the Auto trans operates the same, however the TL is much more controlled. It has loads of inputs compared to mine that uses a throttle position cable to know what the demand is.
Why I mention it, what requires more energy moving a TL or Towing 4000lbs? Which generates more heat in the trans ? The numbers above show it and show they ATF operates at lower temps while not towing, or normal use.
With more modern automatic transmissions against the example I gave you (700r4) the TL is leaps and bounds better as far as efficiency and design.
Crack open the service manual and note the TL PCM is using the following to control how the transmission operates.
Engine RPM
TPS Sensor Signal
ECT Sensor Signal
Barometric Pressure signal
MAP sensor Signal
ATF TEMPERATURE SIGNAL
Consider the J32 uses an integrated exhaust manifold surrounded by coolant, this reduces warm up time, reducing warm up time reduces emissions by allowing the engine to operate in the window that generates the least amount of emissions.
The whole name of the game is to get the engine and trans within their optimal operating temp windows as fast as possible which reduces emissions and maximizes fuel economy. <- The point you disagreed about.
You can argue all you want, the Gen 3 TL never experiences a warmer radiator core than ATF temperatures under normal operating conditions.
No singular point of failure sounds good to me 
