Last post on Sep 05, 2012 at 3:32 PM
You are in the Subaru Forester Maintenance & Repair
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Subaru Forester, SUV
#21 of 31 Clunking transmission followed by AT oil temp warning light and check engin
Jun 15, 2011 (6:03 am)
I have a 2010 Subaru Forester with automatic transmission with 20,000 miles on it. Recently we were in slow freeway traffic for about an hour and a half and the transmission started to clunk alarmingly. Soon after this the AT oil temp warning light came on with a check engine light. We got off the expressway and put it in neutral and after the lights went off we proceeded to where we were going without incident. All weekend no further problem but we stopped at our dealer on the way home and they put the car on their machines to evaluate. Though they saw the event on the history they found nothing wrong with the auto. On the next long trip (about 5 hours) the car was cruising along at 55 miles/hour and again severe clunk followed by the AT oil temp warning light, check engine light and the sport light. A dealer has our auto and we have a loaner. They are driving it around the chicago area to see if it will do it again because they see the event on the history but can't find anything wrong. We will go to pick it up this weekend (6 hour drive) but they don't know what to do for it. Is this common problem?
#22 of 31 Re: Clunking transmission followed by AT oil temp warning light and check engin [deedee59]
Jun 15, 2011 (8:34 am)
This is the first it has come up here, so I doubt it is overly common! If there is that sort of slipping happening in the transmission, I would think it should be noticeable in the fluid itself, either as a burned smell or discoloration due to the overheating of the fluid. Sounds like a fluid flow issue to me. These things operate under hydraulic pressure, so if the pressure goes funky, it will slip out of gear (or not attain a gear in the first place).
Could also be the lock-up on the torque converter; perhaps it is going from lock to unlock in rapid succession? Generally you'll notice the TC lock engaging at the end of acceleration, when you just get up to speed and after the car has shifted into drive. It is very subtle, but there is a final drop in RPM as it settles into cruising speed.
Just throwing out ideas....
#23 of 31 Re: Clunking transmission followed by AT oil temp warning light and check engin [deedee59]
Jun 18, 2011 (5:07 pm)
I'm having the same problem with my 2010 Forrester. I've had it in to the dealer twice. Both times they could not find the problem. The second time they reprogrammed the car's computer. Now, after a 1,000 mile trip with no problems, the problem has occurred again. I'm taking the vehicle to the dealer again next week and may consider invoking my state's "lemon law." Very frustrating ....
#24 of 31 Re: Clunking transmission followed by AT oil temp warning light and check engin [ugen68]
Jun 19, 2011 (11:19 am)
We just picked it up at the dealership and they said that the car had a P0712 code for an intermitent short in transmission harness. Transmission harness was replaced and transmission relearned. We have driven about 350 miles in one trip back home with no problems exhibited. Subaru treated us well.
#25 of 31 Re: Clunking transmission followed by AT oil temp warning light and check engin [deedee59]
Jul 18, 2011 (12:19 pm)
Glad to hear it.
#26 of 31 Re: Check Engine, Dynamics & Cruise Light on 2010 Subaru Forrester [sube2010]
Dec 22, 2011 (2:51 pm)
I have exactly the same problem:
2010 forester with automatic transmission
engine light on+dynamics control light on+blink cruise control light
send to dealer several times, they can't find any code related to this problem, recently it gets worse, one time when I stopped at red light, many lights are on and after turn green, the car just didn't move at all, so I have to restart the car to make it move.
Sube2010, how do you solve the problem finally?
The dealer seems to be clueless
#27 of 31 Re: Check Engine, Dynamics & Cruise Light on 2010 Subaru Forrester [zariesq]
Jan 09, 2012 (3:25 am)
I had a similar problem this summer. It was finally fixed by my dealer by replacing a defective fluid chamber that immediately precedes the transmission. This chamber controls the flow of fluid to the transmission and hydraulically controls the functioning of the transmission. I have had no problems since this repair.
#29 of 31 Re: Check Engine, Dynamics & Cruise Light on 2010 Subaru Forrester [zariesq]
Sep 05, 2012 (9:47 am)
Same problem - 1st time AT temp, Stability, & ABS lights came on while I was in VA. Shut it off for 10 minutes, and all was fine - for 3 months. Last week I was on the Masspike and the car felt like it had been hit. RPM went to 4500, tranny was locked in 3rd. Couldn't even manually upshift. Then the same lights came on and it shifted. Shut it off, restarted, and all lights were off. Started pulling back on the highway, another jarring jolt (enough to chirp the tires), and the lights came back on. No check engine light though. Dealer kept it for a day, and couldn't find anything. No codes means no problems. They said it was down a quart of tranny fluid, but no signs of leaks. They car had just been serviced by them so I asked how the fluid could be low. "You have to check the transmission fluid cold. Went it comes in for service the car is hot so we can't check it." What a line of B.S. The dipstick has two marks - one cold, one hot. Needless to say, that service department has little credibility with me anymore. I reported the problem to Subaru of America, but they claim to have no history of such occurrences. Now they do. The car's going back to the dealer for a week this time after talking to the G.M. I'm not holding out any hope. Nice to have a car with less than 13000 miles on it that you can't trust.
#30 of 31 Re: Check Engine, Dynamics & Cruise Light on 2010 Subaru Forrester [rennwood]
Sep 05, 2012 (1:50 pm)
"... They said it was down a quart of tranny fluid, but no signs of leaks. They car had just been serviced by them so I asked how the fluid could be low. "You have to check the transmission fluid cold. Went it comes in for service the car is hot so we can't check it."
My Owners Manual contradicts that dealer's statement. It says:
"Though the fluid level can be checked
without warming up the fluid on the
“COLD” range, we recommend checking
the fluid level when the fluid is at operating
! Checking the fluid level when the
fluid is hot
Check the fluid level monthly.
1. Drive the vehicle several miles to raise
the temperature of the transmission fluid
up to normal operating temperature..."
Your symptoms are not of low fluid, but something more serious. Maybe your Transmission Control Unit (the E in the 4EAT) has gone haywire.