Towing package radiator 1995 - 2000 ls400
The following users liked this post:
bradland (07-28-18)
07-28-18, 01:52 PM
#18
Is there anything about the AT cooler that makes input-vs-output matter? I assume you could swap either way with no problem, right?
Regarding the experiment, if you're going to that length, it might also be good to get some measurements of the cooling system - radiator hoses, certain parts on the radiator.
Any parts removal (intake thing above the radiator, under-engine splash panels) would be better to get done before driving - easier to do when "cold" and it won't delay taking of the measurements.
Also, most decent multimeters come with a thermocouple attachment, and that might be a more accurate sensor for this application, if you're going to get under the car and remove panels anyway. Maybe more common than an IR pyrometer.
And I would expect that if you were to measure things after a short slow drive home from work, the coolant would be up to temp, and the AT cooler would have done its job to warm up the AT to that temp, holding it there. But if you had a longer drive that made the AT work more, maybe the AT cooler would actually be bringing the ATF temp down to approach coolant temp. ... which is another thing to factor in for your experiment.
Regarding the experiment, if you're going to that length, it might also be good to get some measurements of the cooling system - radiator hoses, certain parts on the radiator.
Any parts removal (intake thing above the radiator, under-engine splash panels) would be better to get done before driving - easier to do when "cold" and it won't delay taking of the measurements.
Also, most decent multimeters come with a thermocouple attachment, and that might be a more accurate sensor for this application, if you're going to get under the car and remove panels anyway. Maybe more common than an IR pyrometer.
And I would expect that if you were to measure things after a short slow drive home from work, the coolant would be up to temp, and the AT cooler would have done its job to warm up the AT to that temp, holding it there. But if you had a longer drive that made the AT work more, maybe the AT cooler would actually be bringing the ATF temp down to approach coolant temp. ... which is another thing to factor in for your experiment.
07-28-18, 03:18 PM
#19
Moderator
07-28-18, 04:43 PM
#20
Lexus Champion
Thread Starter
Is there anything about the AT cooler that makes input-vs-output matter? I assume you could swap either way with no problem, right?
Regarding the experiment, if you're going to that length, it might also be good to get some measurements of the cooling system - radiator hoses, certain parts on the radiator.
Any parts removal (intake thing above the radiator, under-engine splash panels) would be better to get done before driving - easier to do when "cold" and it won't delay taking of the measurements.
Also, most decent multimeters come with a thermocouple attachment, and that might be a more accurate sensor for this application, if you're going to get under the car and remove panels anyway. Maybe more common than an IR pyrometer.
And I would expect that if you were to measure things after a short slow drive home from work, the coolant would be up to temp, and the AT cooler would have done its job to warm up the AT to that temp, holding it there. But if you had a longer drive that made the AT work more, maybe the AT cooler would actually be bringing the ATF temp down to approach coolant temp. ... which is another thing to factor in for your experiment.
Regarding the experiment, if you're going to that length, it might also be good to get some measurements of the cooling system - radiator hoses, certain parts on the radiator.
Any parts removal (intake thing above the radiator, under-engine splash panels) would be better to get done before driving - easier to do when "cold" and it won't delay taking of the measurements.
Also, most decent multimeters come with a thermocouple attachment, and that might be a more accurate sensor for this application, if you're going to get under the car and remove panels anyway. Maybe more common than an IR pyrometer.
And I would expect that if you were to measure things after a short slow drive home from work, the coolant would be up to temp, and the AT cooler would have done its job to warm up the AT to that temp, holding it there. But if you had a longer drive that made the AT work more, maybe the AT cooler would actually be bringing the ATF temp down to approach coolant temp. ... which is another thing to factor in for your experiment.
The radiator operates at 185 F....which is what the engine ECU recognizes. ..however all information available on tranmission temperature vs transmission life expectancy suggests this temperature is above optimum operating temperature.
I like the fact that the radiator imparts heat into transmission cooler/heat exchanger (in radiator) to assist with fluid warm-up...but think even a small fiinned cooler in series with the return fluid outlet will increase transmission life by decreasing returning transmission fluid temperature to 145F-165F.
185F -195F is too high...
Everyone has burnt and or varnished synthetic transmission fluid at 80,000 - 100,000 miles...temperature plays a major part in fluid degradation (besides 20 years of use)
Can anyone aquire a temperature reading at transmission cooler metal return line fitting after a spirited drive in 80F + temperature. Thanks.
07-29-18, 11:18 AM
#21
BTW, the coolant-to-ATF cooler is liquid-liquid, so it will be very efficient, and the output should get pretty close to coolant temp. But the secondary air-to-ATF cooler (above) is much less efficient since it is air-liquid, and varies with air flow and air temp. But the air will be cooler than the coolant, so it will take out some heat.
07-29-18, 12:29 PM
#22
Racer
No disagreement from me on this. Just a matter of whether you need to do something. Two of my cars are Honda Odyssey minivans with notoriously weak transmissions. I have this installed on both of them, following the cooler in the the radiator:
https://www.amazon.com/Long-Tru-Cool.../dp/B008AYQ0R0
https://www.amazon.com/Long-Tru-Cool.../dp/B008AYQ0R0
Nephew just bought a new one.Of course,Honda claims its fixed.I sure hope so,but then again they have been saying that for years now.Honda just fell to #8 on JD Powers,man alive have they lost their way,wow!
07-29-18, 12:36 PM
#23
Racer
So lexus has a tranny problem...I dont think so.This transmission is EXCELLENT and massively durable as proven.Do partial fluid changes frequently and it will never die.Their engineers arent stupid.The auto makers engineers worldwide arent stupid.IF temp killed trannys they would cool them further.
Another 'fix' looking for a problem that doesnt exist on our cars.Waste of time,money,effort and electrons.MAINTAIN your car,including fluid changes.Period.No rocket science here.
Another 'fix' looking for a problem that doesnt exist on our cars.Waste of time,money,effort and electrons.MAINTAIN your car,including fluid changes.Period.No rocket science here.
07-29-18, 02:17 PM
#24
Lexus Champion
Thread Starter
So lexus has a tranny problem...I dont think so.This transmission is EXCELLENT and massively durable as proven.Do partial fluid changes frequently and it will never die.Their engineers arent stupid.The auto makers engineers worldwide arent stupid.IF temp killed trannys they would cool them further.
Another 'fix' looking for a problem that doesnt exist on our cars.Waste of time,money,effort and electrons.MAINTAIN your car,including fluid changes.Period.No rocket science here.
Another 'fix' looking for a problem that doesnt exist on our cars.Waste of time,money,effort and electrons.MAINTAIN your car,including fluid changes.Period.No rocket science here.
A well maintained 1UZ-FE engine will easily last 500,000 + miles...
Not many automatic transmissions last that long....
One of the factors to transmission life expectancy is operating temperature....
I didn't conjure this one up....
Right now am requesting whether anyone can provide transmission fluid temperature readings at inlet and outlet of transmission cooler fittings...
In that way what you know then is more than what you know now.
Thanks.
07-30-18, 01:37 PM
#25
Racer
Keep the fluid changed/refreshed.Thats the answer.
Last edited by spuds; 07-30-18 at 01:53 PM.
07-30-18, 01:59 PM
#26
That million mile LS400 is still going. Did Matt install in a trans cooler? I do agree that reducing temps can play a part as well as regular fluid changes. I'm not aware on this forum of owners having an ATF fluid analysis to check additive package longevity to the intervals. Having that data will provide additional insights.
07-30-18, 03:04 PM
#27
Lexus Champion
Thread Starter
No.IMO the factor of heat relates to transmission OIL longevity.Burn up the oil and burn out its additives,burn up the tranny.Why do you want to keep used up,DIRTY oil in your tranny in ANY event? You sure dont need a 'sludge' (lol,had to say it) of metal particles and clutch material floating around the tranny.None of that is healthy.
Keep the fluid changed/refreshed.Thats the answer.
Keep the fluid changed/refreshed.Thats the answer.
In the meanwhile the transmission fluid is at (or above) engine temperature... (not supposing cooler) which, based on information appears too hot.
For maximum life, what then is optimum fluid temperature??
Anyone wirh data for our transmission(s)
Plastic and or elastomeric transmission components endure longer at lower operating temperatures.
Posted transmission temperature charts don't provide whether life expectancies are based on changing fluid at regular intervals.
Wondering too whether said charts pertain to synthetic fluid.
My guess is these statistics are based on not changing fluid at all...
No one is suggesting life expectancy, even with regular transmission fluid changes, is improved by increasing operating fluid temperature ..
Still seeking temperature readings at transmission cooler fittings at radiator....
07-31-18, 09:26 AM
#28
Well the fluid changes are definitely frequent enough. Should have no issues there.
One of my other cars is an X5, and this thread came up recently, which might be similar to a solution Yodaone is looking for.
https://xoutpost.com/bmw-sav-forums/...-solution.html
The first post tells the whole story, with pics.
My summary: Basically, on the X5's the engine coolant thermostat is at 108*C, and often runs hotter than that. This is done for emissions and fuel economy, NOT for AT longevity. The AT cooler attached to the radiator (separate, but is a coolant-to-ATF liquid-liquid heat exchanger) basically sets the ATF to that temp, and the AT is hopefully strong enough to tough it out past the warranty period or typical trade-in time of BMW's typical customers.
The guy had a specific issue on his AT that he traced (using the boatload of sensors these X5 are equipped with) to the ATF temp rising above 95C.
So he put in the biggest external ATF cooler he could fit, after the stock coolant-to-ATF cooler, along with a bypass thermostat set at 80*C to prevent overcooling (which would be a real concern if the air was cold, etc., given an external cooler that big). Now the ATF runs at a solid 80*C and ... the AT problem is gone, still 20k+ miles later. If you read the discussion, there are still some people saying it was unnecessary.
One of my other cars is an X5, and this thread came up recently, which might be similar to a solution Yodaone is looking for.
https://xoutpost.com/bmw-sav-forums/...-solution.html
The first post tells the whole story, with pics.
My summary: Basically, on the X5's the engine coolant thermostat is at 108*C, and often runs hotter than that. This is done for emissions and fuel economy, NOT for AT longevity. The AT cooler attached to the radiator (separate, but is a coolant-to-ATF liquid-liquid heat exchanger) basically sets the ATF to that temp, and the AT is hopefully strong enough to tough it out past the warranty period or typical trade-in time of BMW's typical customers.
The guy had a specific issue on his AT that he traced (using the boatload of sensors these X5 are equipped with) to the ATF temp rising above 95C.
So he put in the biggest external ATF cooler he could fit, after the stock coolant-to-ATF cooler, along with a bypass thermostat set at 80*C to prevent overcooling (which would be a real concern if the air was cold, etc., given an external cooler that big). Now the ATF runs at a solid 80*C and ... the AT problem is gone, still 20k+ miles later. If you read the discussion, there are still some people saying it was unnecessary.
07-31-18, 01:16 PM
#29
Lexus Champion
Thread Starter
Well the fluid changes are definitely frequent enough. Should have no issues there.
One of my other cars is an X5, and this thread came up recently, which might be similar to a solution Yodaone is looking for.
https://xoutpost.com/bmw-sav-forums/...-solution.html
The first post tells the whole story, with pics.
My summary: Basically, on the X5's the engine coolant thermostat is at 108*C, and often runs hotter than that. This is done for emissions and fuel economy, NOT for AT longevity. The AT cooler attached to the radiator (separate, but is a coolant-to-ATF liquid-liquid heat exchanger) basically sets the ATF to that temp, and the AT is hopefully strong enough to tough it out past the warranty period or typical trade-in time of BMW's typical customers.
The guy had a specific issue on his AT that he traced (using the boatload of sensors these X5 are equipped with) to the ATF temp rising above 95C.
So he put in the biggest external ATF cooler he could fit, after the stock coolant-to-ATF cooler, along with a bypass thermostat set at 80*C to prevent overcooling (which would be a real concern if the air was cold, etc., given an external cooler that big). Now the ATF runs at a solid 80*C and ... the AT problem is gone, still 20k+ miles later. If you read the discussion, there are still some people saying it was unnecessary.
One of my other cars is an X5, and this thread came up recently, which might be similar to a solution Yodaone is looking for.
https://xoutpost.com/bmw-sav-forums/...-solution.html
The first post tells the whole story, with pics.
My summary: Basically, on the X5's the engine coolant thermostat is at 108*C, and often runs hotter than that. This is done for emissions and fuel economy, NOT for AT longevity. The AT cooler attached to the radiator (separate, but is a coolant-to-ATF liquid-liquid heat exchanger) basically sets the ATF to that temp, and the AT is hopefully strong enough to tough it out past the warranty period or typical trade-in time of BMW's typical customers.
The guy had a specific issue on his AT that he traced (using the boatload of sensors these X5 are equipped with) to the ATF temp rising above 95C.
So he put in the biggest external ATF cooler he could fit, after the stock coolant-to-ATF cooler, along with a bypass thermostat set at 80*C to prevent overcooling (which would be a real concern if the air was cold, etc., given an external cooler that big). Now the ATF runs at a solid 80*C and ... the AT problem is gone, still 20k+ miles later. If you read the discussion, there are still some people saying it was unnecessary.
The author posted before and after transmission temperature readings from diagnostic tool...the "before" transmission fluid temperature resembles coolant temperature..
Our Lexus transmissions incorporate a temperature sensor however am unsure whether diagnostic tools display this information...
Last edited by YODAONE; 07-31-18 at 01:23 PM.
07-31-18, 02:19 PM
#30
Racer
I can write the final post now.....
This has completely eliminated the harsh 1-2 downshift that so commonly plaques our cars.Shifting is also notably smoother across the board.Also lower temps we all agree will increase the longevity of our transmissions as shown in the heat charts.
Feel free to just copy/paste this when youre done.