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Not sure if you have an AWD or RWD, but here's a pic of the cooler on the RWD 350. It's on the passenger side of the tranny.
In the pic the bell housing is on the right (towards the front of the vehicle) and the Park/Neutral switch is on the left (towards the back of the vehicle).
I would assume it is adequate to cool the tranny as no one has had tranny failures on the 3IS.
The specific operating temp will vary depending on location and operating conditions.
Fluid adjustment is done between 97-126F...but really the tranny can go higher than 126F depending on location and operation.
So while driving around in 80* ambient temps, my coolant was 186*F but the transmission was 201*F. And that was not racing around. Without redesigning the transmission cooler, would there be any negative impact to run a aux cooler in the coolant lines that supply the transmission cooler so that the coolant has a lower temperatue than the engine before cooling the ATF?
I ran an aux transmission cooler on my old Subaru Legacy GT when I tuned it.
For Lexus and these transmissions though, I don't think I'd touch it for any typical street driving. These transmissions, especially the 6spd, have proven to be incredibly reliable. I see no reason to make changes unless you plan on tracking it or something.
Does the IS350 have a separate tranny cooler outside of the radiator? I didnt see any cooler ports on replacement radiators.
my understanding is the 6 speed tranny uses external cooler lines with engine coolant to cool off the transmission. I have seen a video where after 2-3 full laps at a track the transmission engine temp warning indication appeared.
So while driving around in 80* ambient temps, my coolant was 186*F but the transmission was 201*F. And that was not racing around. Without redesigning the transmission cooler, would there be any negative impact to run a aux cooler in the coolant lines that supply the transmission cooler so that the coolant has a lower temperatue than the engine before cooling the ATF?
If you wanted to rig up a seperate cooler, I don't see an issue with that. You would need to figure out which line is the inlet and run it into the aux. cooler and from the cooler back into the transmission cooler. You'd need to find space in the front of the vehicle to place the cooler...the downside is that you have now created several new points where the coolant system could fail.
It's great that you have been monitoring the temp.'s, but I guess the question is...is there a problem? Since the A/T Temp. light hasn't come on, then it's not overheating.
It's like trying to fix an engine overheating issue when the Engine Temp. gauge is reading in the middle...there's nothing to fix cause there's nothing broken.
Originally Posted by Drcoffee
Is there a alternate part that incorporates an aux cooler, let’s say from a Tundra or Tacoma with a tow package? The RWD uses the 8sp trans.
No one has made an attempt to fit an aux. cooler as no one has run into a cooling issue, so I don't think there is an answer to your question.
If you do install one, perhaps you can post what you did for the install. It's possible that someone somewhere may want to do the same.
B&M Transmission Cooler Model: 70264 - Brand New - MSRP $100+ - i think i pad 175 but prices went down on it Brand New Radiator Hoses Goodyear - 25 ft. genuine - $60 Radiator Hose insulation cover - $15 7" Cable Ties - $3 Mookeh Trans Temp Gauge - Brand New - LED never installed - $75
What happened later to Sedans on Hondas at least was they only added Trans coolers way after adding them to MiniVan or SUV...this led to a lot of failures from V6 owners, not so much to 4cyl. but the Horsepower difference is substantial
On the 3IS, if we already got one, only thing i would recommend if you ABSOLUTELY want to "upgrade" stay OEM and see if other Models that may have bigger coolers could help
either way, please post your results....you may be a pioneer man as i don't know of anyone changing the OEM one
here's my old Thread for the 2003 Honda Accord V6:
also, i wouldn't worry too much about that Automatic Transmission Temperature number...when i was monitoring my Coolant...it was around there to give you a reference point:
05-16-20, 12:32 PM
Does the IS350 have a transmission cooler
