Jump to content


Welcome to Ultimate Subaru Message Board, my lurker friend!

Welcome to Ultimate Subaru Message Board, an unparalleled Subaru community full of the greatest Subaru gurus and modders on the planet! We offer technical information and discussion about all things Subaru, the best and most popular all wheel drive vehicles ever created.

We offer all this information for free to everyone, even lurkers like you! All we ask in return is that you sign up and give back some of what you get out - without our awesome registered users none of this would be possible! Plus, you get way more great stuff as a member! Lurk to lose, participate to WIN*!
  • Say hello and join the conversation
  • Subscribe to topics and forums to get automatic updates
  • Get your own profile and make new friends
  • Classifieds with all sorts of Subaru goodies
  • Photo hosting in our gallery
  • Meet other cool people with cool cars
Seriously, what are you waiting for? Make your life more fulfilling and join today! You and your Subaru won't regret it, we guarantee** it.

* The joy of participation and being generally awesome constitutes winning
** Not an actual guarantee, but seriously, you probably won't regret it!

Serving the Subaru Community since May 18th, 1998!

Guest Message by DevFuse
 

Photo
- - - - -

Trans Converter Lock-Up Question


  • Please log in to reply
2 replies to this topic

#1 Exocet

Exocet

    New User

  • Members
  • PipPip
  • 17 posts
  • Central NY

Posted 26 December 2003 - 08:56 PM

My 94 Legacy's automatic transmission takes longer to lock-up the torque converter in the winter. I know that it should, as it waits for the transmission to get up to temp before locking up. However, it seems a bit erratic in terms of the distances you have to drive before lock-up occurs. For similar ambient temps (20-30 deg F), most of the time it locks-up within 1-2 miles of driving, other times it goes 10 miles without locking up. It only behaves this way in the winter. During the summer, this doesn't happen. Lock-up is almost immediate. This would appear to indicate a possible problem with the temp sensor in the transmission. But, it could be more serious I suppose. Anyone have anything similar happen?

#2 alias20035

alias20035

    Subaru Fanatic!

  • Members
  • 357 posts
  • Canada

Posted 27 December 2003 - 12:44 AM

Originally posted by Exocet
My 94 Legacy's automatic transmission takes longer to lock-up the torque converter in the winter. I know that it should, as it waits for the transmission to get up to temp before locking up. However, it seems a bit erratic in terms of the distances you have to drive before lock-up occurs. For similar ambient temps (20-30 deg F), most of the time it locks-up within 1-2 miles of driving, other times it goes 10 miles without locking up. It only behaves this way in the winter. During the summer, this doesn't happen. Lock-up is almost immediate. This would appear to indicate a possible problem with the temp sensor in the transmission. But, it could be more serious I suppose. Anyone have anything similar happen?



Possibly a bad engine coolant temperature sensor. The torque convertor will only begin to lock when the engine is warm, not when the transmission is warm. As far as I know the transmission sensor is just there to indicate transmission overheat conditions.

By not locking up the torque convertor, the engine will warm up faster and more importantly the catalytic convertor will "light up" faster to reduce emmissions. This fact is stated in your owner's manual, and I believe that there are a few TSB's out there to provide to owners who complain about odd cold temperature transmission performance.

The engine coolant temperature sensor is a very routine item, practically affecting all Subaru's at one point or another. Erratic transmission low temperature performance is one of the signs of trouble, but usually improper idle is the primary symptom.

But if the torque convertor eventually does lock up, it's very possible that nothing is wrong. Track how long it takes the engine to warm up, if the engine takes a long time to warm up the torque convertor should also take longer to begin normal operation.

To help your engine warm up faster turn off your heat until the engine is warm, with the exception of blowing air through the defrost vents to avoid frost buildup on the windshield.

If the engine takes a really long time to warm up, or you never get "hot" heat, then it is possible that your thermostat is stuck open, and your engine is running too cold, which will in turn prevent the torque convertor from locking up.

At 0 C (32 F) both my 93 Legacy and 01 Outback were at temperature within 3 or 4 minutes of driving.

At -10 C (14 F) it takes about 6 minutes of driving to reach temp.

Even at -30C (-30F) it only takes about 10 minutes.

If your engine takes more than 10 minutes to warm up you either are taking away too much engine heat to warm the interior or have a thermostat that is stuck open.

Below -7C (20F) it is advisable to plug in your cars engine block heater (if you have one, if not consider getting one). You only need to plug in the block heater 3 hours before startup, you do not need leave it plugged in overnight, and timers are availble to turn on the block heater automatically. By using the block heater you will cut your engines warm up time by half or more, improve cold weather starting, reduce fuel consumption (saves way more $ of fuel than the $ electical usage), and reduce engine wear. Subaru block heaters usually replace the driver's side engine coolant drain plug.

Given that you are in central NY you should have a block heater already installed? They are standard items on all Subaru's in upstate NY, VT, ME, and NH, and have been since at least 1990. SNE (Subaru of New England) orders all Subaru's from the factory with the block heater already installed.

#3 Exocet

Exocet

    New User

  • Members
  • PipPip
  • 17 posts
  • Central NY

Posted 27 December 2003 - 03:27 PM

Thanks for the informative response. The car seems to warm up normally, within 3-4 minutes of normal driving. The car doesn't have any noticeable cold weather driveability problems. The coolant sensor went bad about 40K miles ago and was replaced. That doesn't mean it isn't going bad again, it just isn't bad enough to cause driveability problems or trip the "check engine light".

This morning, after sitting all night in a 35-40 deg F garage, I drove the car about 10 miles at 65-70 MPH. The torque converter didn't lock up until after driving 7-8 miles. The outside temp was about 35 deg F.

The car does have a block heater, but since it is parked in a garage, it has rarely been used.

I suppose I should pull the coolant sensor and check it, or just replace it, if it isn't too expensive.




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users