Automatic transmission overheating

fandizzle

fandizzle

Forum Member
Joined
Sep 14, 2008
Messages
221
Location
brissy
Car Model
XT
Hi guys,

I have a problem with my 2006 auto forester xt! When I am driving on the beach or up steep hills under load my transmission temp will rise up to 140 degrees with ease! Yes I know that's hot. And yes I've got a gauge that tells me the temperature. I've got a larger mishimoto oil cooler with a fan on it that is seperate to the radiator. There doesn't appear to be any slip.

Has anyone had a problem or can help me?

Thanks
 
Perhaps something is impeding the air flow through your tranny cooler on either the inlet or outlet side?

e.g. large spotlight; sump guard.
 
DO you have it "locked" into a single gear or just left in "D"
Also have you left the factory cooler (in the radiator) left in the flow-path?
 
Is the factory cooler bypassed? Is the fluid level ok? How is the fan wired in? Temp sensor? Manual switch? Constant?

Process of elimination. Make sure the fan is working. Make sure the fluid is flowing. Bypass the stock cooler if you haven't already in case it's clogged. How old is the external cooler? Could that be clogged up? If all seems normal, make sure it's not a faulty temp sensor.
 
Trust me I've exhausted all of the basic solutions. I've hard my bar off a million times. Its a brand new cooler. Ive wired the fan up into the cabin so I can turn it on whenever and yes it works. Auto box has been serviced with the best oil in it
 
Any update on this? I'm curious about what the issue could be.
I'm not incredibly familiar with the internals but was this the first transmission service it's had? Could the clutch packs be slipping? Is there enough pressure to flow through the cooler? Could the sensor be faulty or is it or the lines close to something else that could be heating it up like the exhaust?

Most don't heat up too bad even with the cooler bypassed. We bypass them all the time so customers can drive their car until we can put new lines/radiator in. So I'm just curious what could be happening.
 
It's had two services in the year I've had it. Yea that's a good idea about the packs but here is no slippage at all! I think the next trick will be to pop the return Jose off the transmission to see if it's pimping through and back into the box. My transmission. Sensor to my gauge is new and the AT transmission dash light also comes on around 130 so I don't think there is any fault there
 
Transmission internals aren't my strong point. Seems they're all way too different these days. But I will say this. Once you reach over a certain number of miles on them, servicing them can be a baaaad idea. lol.

I never did the service on my Sentra but now that it has just over 100k miles, I'm scared to service it. :poke:
 
A torque converter lock up mod will do it. Ive been doing this to Forestets both turbo and non turbo (mosy turbo due to the same issue). With an upgraded tranny cooler it has fixed the over heating issues when towing or in soft sand(high load situations offroad).
Ive also fitted a few aftermarkey lock up aystems to 200 series landcruisers and various auto 4wds.
 
An issue here is that Fandizzle should not require work around mods to fix his transmission problem. He and I have the same car with the same performance/off road mods and I never have trans temp problems under more demanding driving conditions. We have talked through his situation at length in an attempt to fault find the source of the heating but no solutions have worked to date. He's had the car to several specialists who are also stumped.
 
It's not even when I engage the lock up, it's in any gear anytime. Have you any experience with the larger PWRcooler with the fan?
 
I'm stumped as well. I'm assuming the temp sensor is mounted on the cooler? If not, maybe bypass the cooler and run the stock cooler to eliminate a blockage in the cooler. Manufacturing defect perhaps? I see that a lot.

You can also try and check the pressure before and after the cooler. And make sure non of it is running near anything else hot. Other than that I haven't a clue. Unless the wrong fluid was put in your car. If have to assume you checked the fluid level but you never know. I've seen a lube tech drain the tranny instead of the oil by mistake. Lol

Is there a temperature change from fan off to fan on? What does it do in steady state driving above 30?
 
I've been watching this thread and hoping that someone comes up with an answer. I have AT and the normal OEM external AT cooler (still running through the radiator) and yes, it will get hot on sand but reflected though the radiator temp increasing. Crossing the Simpson, Morton and Fraser were all OK only issue is when I go onto Stockton beach in very soft sand and travelling with the wind - against the prevailing wind and there is no issue. Seems like you have done all the right things to keep the AT cool and maybe it is a ATF flow issue.
 
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