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AT Oil Temp flashing immediately after starting enging, transmission rebuilt 2 years ago

1.6K views 5 replies 6 participants last post by  Brandon5736  
#1 ·
I bought our 08 Outback (automatic) about 4 years ago in a pinch when my husband and I were stranded away from home. Not knowing too much about cars we bought it unaware that the transmission was slipping. We took it to a local transmission mechanic who replaced it, but he said the valve body was on back order for upwards of a year. He asked if we wanted to pay for it upfront and that when it came in he would call us replace it, so we agreed. He told us that since he couldn't replace it that we should redline it occasionally. Fast forward a year and a couple months, no word from the mechanic so I give him a call, receipt in hand. He goes on to say that we had no such agreement, he never ordered the valve body, and that his warranty only spans one year (despite the fact that he never completed the job or even gave us the part). I looked back at the receipt and he had a very vauge note about replacing the valve body at a later date. He didn't have anything itemized, just a flat charge of $2000. I tried to debate with him over the language on the receipt, only to be hung up on several times, so I never was able to get any resolution.

A few days ago I was driving home, after the car had been sitting for a couple of hours, when the AT Oil Temp light starts flashing. Luckily I was near a friend's house, so I was able to pull it over immediately and park it to take a look. We let the car cool for a while then started it up again. It only took about a minute for the light to start flashing again, enging not even warm yet. We haven't been experiencing and slipping or knocking, fluid looks clean.

After asking a few friends who know a bit about mechanics and they said it could be the valve body needing cleaned/replaced. I only just remembered that the transmission mechanic said to redline it occasionally, which we haven't done at all. My question is, if the engine isn't even warmed up, could the fluid really be getting that hot that quickly, or is it maybe a sensor/filter gone bad? Should I try to redline it to clear it out, or is that a big risk considering? If the valve body does need manually cleaned or replaced, is it in an accessible spot to reach fairly simply?
 
#2 ·
It's pretty unlikely that the transmission fluid is getting hot that fast if the engine isn't even warmed up. Sounds more like you might have a sensor problem or something wrong with the wiring. I wouldn't recommend redlining the car to try and fix it, that could actually make things worse if there's a serious issue going on. As for the valve body, it's pretty complex and usually needs a bit of the transmission taken apart to get to it, so you might want to let a pro handle that.
 
#3 ·
. . . we bought it unaware that the transmission was slipping. We took it to a local transmission mechanic who replaced it, but he said the valve body was on back order for upwards of a year.
Did the local mechanic replace the transmission? If so, with a new one, a "rebuilt" one, or a used one? And, was it replaced knowing the replacement was faulty, i.e., needed a valve body?

My question is, if the engine isn't even warmed up, could the fluid really be getting that hot that quickly, or is it maybe a sensor/filter gone bad?
There's two ways the AT Oil Temp light warns of a problem. One is by turning on and staying on, i.e., steady, the other is it flashes on and off. The first indicates that the temperature of the transmission fluid is unusually high. The latter indicates that the on-board diagnostic system has detected a fault, other that the fluid temperature being too high.

When the light is flashing, the related code or codes can be read through the OBD connector port, using a scanner tool that can access the transmission's control module. The code will indicate the area of the problem, and that can help diagnosis and repair. (Some auto parts stores will read codes for you, although not all have readers that can read the transmission codes.

In regard to the fluid level, this is checked with the car on a level surface, warmed up, and engine running. If it's checked with the engine off, it could show full or above full, but that is not correct.

Incidentally, the information above, and a lot more, is in the 2008 Owners Manual. If the car did not come with the manual, a copy can be downloaded from Subaru. Go to https://techinfo.subaru.com/stis/#/login, click on "Online Reference", select Owners Manual in the list on the left side, the year, model and trim to the right, and Search. The 2008 Owners Manual will be listed on the next page (as of this writing), with a download arrow to the right.

It would be helpful if the engine type (2.5 non-turbo, 2.5 turbo, or 3.0), transmission (manual, 4-speed or 5 speed), and the mileage. were indicated here.
 
#5 ·
Solenoid issues usually come up as problems in either the 4 or 5 speed trans. It doesn't require a valve body replacement. Sometimes it's a harness problem.

As @plain OM posted, the TCM has faults stored and the fault(s) will give a direction to go.

Your only option with the shop is small claims.
 
#6 ·
I recently had the same issue along with a check engine light. It seemed to be ECM issues. The computer was not communicating between the engine and transmission. The only difference is I had a Bluetooth scanner plugged in at the time. After shutting the car off and clearing codes it seemed to be fine. Also did yours seem to go into a "limp" mode too?