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01 Forester
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Discussion Starter #1
So being that I do live in Canada, it is starting to get a little chilly. Since its been under about 10*c, when the Foz is cold, the transmission will not shift into 4th. It takes until the temp gage gets to the normal place and then will downshift and its fine for the rest of my drive. Happens everytime its below 10 or so. Is there anything I can do to try to fix this? I'm on the highway pretty quickly for my drive to work, so I am using more gas than I need to while I'm in 3rd instead of 4th until it warms up.

Any ideas anyone?

Thanks
-Rick

'01 Forester with auto
 

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2003 Subaru Forester SG5 5MT
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199 Posts
I guess you were going to say 'upshift'. As far as I know it's Ok. It was like that on my prev. auto sf5 Foz when it's below zero outside. atf needs to get warmer that's why it is being warmed in the contour in main radiator when it's cold (just like cools down when it's too hot).
 

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2015 Highlander AWD XLE 6AT
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4,259 Posts
Any ideas anyone?
The "cold non-upshift" is probably normal; my old pickup behaves similarly. Not sure about Subaru's instantiation, but my pickup's AT includes an internal bypass valve that keeps circulating ATF out of the external warming/cooling circuit (separate oil-to-water- and oil-to-air radiators in series) until it warms up a bit.

HTH,
Jim / crewzer
 

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2008 LL Bean (4EAT)
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4,909 Posts
... its been under about 10*c, when the Foz is cold, the transmission will not shift into 4th. It takes until the temp gage gets to the normal place and then will downshift and its fine for the rest of my drive. Happens everytime its below 10 or so. Is there anything I can do to try to fix this? I'm on the highway pretty quickly for my drive to work, so I am using more gas than I need to while I'm in 3rd instead of 4th until it warms up...
Manufacturers use the automatic transmission to help the engine warm up faster. In the case of my Forester, the transmission is programmed to upshift at higher RPMs until the engine is warmed up.

2008 Forester Owners Manual, page 7-11:
NOTE
. When the engine coolant temperature
is still low, your vehicle’s automatic
transmission will up-shift at higher
engine speeds
than when the coolant
temperature is sufficiently high in
order to shorten the warm-up time and
improve driveability. The gearshift timing
will automatically shift to the normal
timing after the engine has warmed
up....
In the case of my Scion xB, the manual states that the automatic transmission will not upshift unto 4th gear until the blue temperature light has gone out. This would be 137F according to the ScanGauge on my Scion which is not automatic. The manual says this is to hasten warm up. So I don't shift my 5-speed into 5th until the blue light is out.

In your case, either of those two methods might be used, or maybe there is no such fancy control, and your fluid is just to cold and thick to allow an upshift for until it warms up a little.

Edit: Just noticed you said 10C. I was thinking you had said 10F. 10C is not cold enough to slow shifting.

In any case, your engine would not be saving gas running cold in 4th gear. It will save more gas by warming up faster at higher RPMs in 3rd, so that it can run efficiently sooner.
 

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In any case, your engine would not be saving gas running cold in 4th gear. It will save more gas by warming up faster at higher RPMs in 3rd, so that it can run efficiently sooner.
Do you have any documentation that supports this ?? I agree that a warm engine runs more efficient that a cold one, but I doubt that you will "save" gas by running cold in a higher gear until the engine warms up.

I'm not saying that I know for a fact that you are wrong, it just doesn't sound right to me.

When I take off in the morning I use the auto stick to push my 09 into 4th as fast as possible. Part of the reason is that I've got to believe that running the engine slower while it's cold results in less wear on the internals.
 

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2008 LL Bean (4EAT)
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Do you have any documentation that supports this ?? I agree that a warm engine runs more efficient that a cold one, but I doubt that you will "save" gas by running cold in a higher gear until the engine warms up...
Obviously you are not saving gas as you run cold at higher RPMs in 3rd. You are warming the engine faster so it will be able to save gas in any gear sooner.

You asked why your Forester stayed in 3rd longer when cold. Are you asking for documentation on why Subaru and Toyota force their engines to higher RPMs when cold by delaying or preventing upshifts to 4th until a certain temperature is reached?

I provided the quote from the Forester manual. If you want the quote from the Scion manual, I don't have it digitally.

You could ask your dealer about the reason for delayed shifting when cold.
 

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Obviously you are not saving gas as you run cold at higher RPMs in 3rd. You are warming the engine faster so it will be able to save gas in any gear sooner.

You asked why your Forester stayed in 3rd longer when cold. Are you asking for documentation on why Subaru and Toyota force their engines to higher RPMs when cold by delaying or preventing upshifts to 4th until a certain temperature is reached?

I provided the quote from the Forester manual. If you want the quote from the Scion manual, I don't have it digitally.

You could ask your dealer about the reason for delayed shifting when cold.
Actually I'm not the OP and I didn't ask why SOA stays in 3rd when cold. I questioned if there really was a gas savings by doing so.

I know why SOA and others hold hold a lower gear when cold, they do it to meet EPA air pollution requirements. They need to get the catalytic converter(s) hot quickly because there is a limited threshold that they are allowed to run "dirty". That is also why a cold engine idles so annoyingly fast.

The pressure to meet air pollution requirements is greater than any pressure to get good mileage or reduce engine wear.
 

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2008 LL Bean (4EAT)
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... You asked why your Forester stayed in 3rd longer when cold. Are you asking for documentation on why Subaru and Toyota force their engines to higher RPMs when cold by delaying or preventing upshifts to 4th until a certain temperature is reached? I provided the quote from the Forester manual. If you want the quote from the Scion manual, I don't have it digitally....
I found the Scion info digitally, on page 96 of the 2006 Owners Manual:
(c) Normal driving...
When the lever is in the “D” position, the
automatic transmission system will select
the most suitable gear for running conditions
such as normal cruising, hill climbing,
hard towing, etc.
Always turn the overdrive on for better
fuel economy and quieter driving. If the
engine coolant temperature is low, the
transmission will not shift into overdrive
gear even with the overdrive on.
Subaru and Toyota, and others no doubt, use the automatic transmission to make the engine warm up faster.
 

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2008 Forester 2.5X
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Try just letting the car idle for a couple of minutes (2-3) with the heater fan off in the morning before you take off. On my 08, that's about all it takes to get the engine near normal operating temperature above about 10 degrees F.
 

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2003 Subaru Forester SG5 5MT
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Try just letting the car idle for a couple of minutes (2-3) with the heater fan off in the morning before you take off. On my 08, that's about all it takes to get the engine near normal operating temperature above about 10 degrees F.
Too risky from my point of view. Although it will take the engine to the working temp sooner, there is a risk of switching on hot air to the windshield (accidentally or not) which can cause a crack.
I prefer to keep climate always in auto mode when it decide itself when and where should be blow the air.
Btw, when the car is idling while warming, climate change the fan speed and air blowing direction according to the engine temp. If it's cold, the fan speed is low. But climate always set it to blow on windshield from the beginning, so it gets warmed little by little avoiding blowing hot air on the cold windshield.

I believe it's enough to just warm the car as usual, and drive it in a calm manner (first mile(s) depending on the outside temps). As the atf gets warm and closer to the proper working temp, it shifts ok.

Overall, just don't 'kick it' and that's all. Not an issue to think a lot about :).

btw, it's a good practice also to avoid driving over bumps and holes at high speed when the struts a cold. This can make'em last longer.
 
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