Modern instrument panels provide more information about the vehicle than ever before. What used to be a few crucial warning lights and a check engine light has turned into a self-diagnosing system that will tell you exactly what’s happening.
AT oil temp means that the automatic transmission oil temperature has crossed the upper limit. There is no other way to fix the problem but to drive, or tow your vehicle to a Subaru dealership or mechanic.
The AT, or A/T oil temp light will light up and start flashing if the oil inside the transmission becomes too hot. Simply speaking, transmission is a set of gears inside a housing. The clutch connects the engine with the transmission to allow the power transfer.
The engine spins the crankshaft at different speeds but always delivers the same amount of power. The direct drive or 1:1 gear ratio happens when the transmission is in the fourth gear. This means that without a transmission, the car would constantly be in fourth gear, which would make it incredibly difficult, if not impossible to get moving.
That’s why lower gears exist. They convert several revolutions of the engine into a single revolution of the wheels. The highest gears, called overdrive, spin faster than the engine, allowing the car to reach greater top speeds.
It’s good to know all of this, but if you want to take only one fact out of it – the transmission is a power converter, not a power generator. It’s designed to operate in set conditions of an enclosed environment.
Like I said in the article covering the engine oil light (you can find it here) whenever you see a warning light with the word oil in it, immediately pull over and turn off the engine.
This rule isn’t up for debate and has no exceptions. Transmission oil is somewhat cooled by the airflow beneath the vehicle, but that’s not enough. Stop the parts from moving as soon as possible.
If you’ve read my other guides on Vehicle Freak, you know I’m all for DIY repairs. The way I see it, you’re learning a new skill and equipping your garage with new tools by just using the money you’d give to a mechanic.
However, some repairs are just beyond a DIY job. You might assume that changing the transmission oil is no different from changing engine oil – but it’s an entirely different beast. You take a look at the following video guide and see just how much work and skill go into changing the oil.
The first thing to realize is that transmission oil is changed at set intervals. Your service book should have a record of the last oil change, and when to change it again. Overheating transmission oil is likely caused by a mechanical issue inside the transmission, something only a professional can identify and repair.
Subaru is not a cheap vehicle to maintain, especially the powertrain. The cost of a fluid transmission change is around $200, and that’s the cheapest possible fix.
Determining the actual cost of repair is difficult without knowing what’s broken, but you should expect the expenses to start at $1,000, with an average cost of around $2,000. A complete transmission refurbishment or replacement will set you back as much as $3,500.
My advice would be to have the vehicle inspected and the transmission oil changed. If the problem hasn’t been solved, weigh the current value of the vehicle to several thousand dollars in repairs. If the math doesn’t add up, sell the car instead of repairing it, and use it to buy another vehicle.
Of course, like any responsible car manufacturer, Subaru includes an oil change light in all of its vehicles, or at the very least, a service indicator. You should still keep your own records as it’s a good practice, helps you stay on top of maintenance, and ultimately increases resale value.
Hot transmission fluid could indicate a low oil level or a mechanical issue that’s causing friction and generating heat. Whichever the case, you should have a mechanic inspect and repair it, rather than doing the job yourself.
Subaru transmission fluid generally runs at 175° Fahrenheit. The temperature can be a bit higher than that, but anything beyond 200° is considered unsafe.
I hate to disappoint you with a guide that’s only going to point you towards a mechanic, but in some cases, that’s the best, and only course of action.
Transmission is far too complex of an assembly for any home mechanic to tackle, and even the local jack-of-all-trades mechanics refuse to work on them. An authorized dealership or a Subaru mechanic will assist you in identifying and solving the problem.
Check out these related topics about Subaru cars:
How Many Gallons Does A Subaru Outback Hold?
How Does Subaru Outback Remote Start Work?
How Long Do Subaru Cars Last? – Complete Explanation
