Newer automatic transmissions (especially on Toyotas)

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coolcat21

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Topic # 127416 9-Aug-2013 12:22

Hey guys,

I have a question regarding my car's auto tranny.

It's a 2004 Toyota Corolla allex , with the 1.5 engine and the same exact transmission as the 2006-2011 Toyota Yaris.
So if you have a yaris of that year or similar to my car, that'll be even better.

I just got the car last week and I guess I am not used to it yet.

The problem is when i'm travelling at 40 km/h and above , if i let go of the gas to coast (slight downhill , traffic light approaching etc.) ...the car seems to slow down unnaturally , like how if you let go of the gas in a manual transmission car , it kinda jolts you abit.

And then if I don't do anything and let it just slow down , the rpm eventually goes slight below 1000 ...and then it jumps 250 rpm (rev bounce) ?

Is this normal ?? I checked the t-fluid , it's still red with a candy like smell.

It's done 65,000 KM

Oh and also , when I press the power window button to roll it up , halfway up it makes a clunk sound (like if someone throws a small stone at your window) , ......it doesn't stop it or slow it down, just makes that noise, and a slight grind sound. The other 3 windows roll up/down like butter.

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Reply # 874533 9-Aug-2013 12:41

Sounds like the lockup clutch in the torque convertor might be engaging at low speeds, although I doubt that would be a common problem.

coolcat21

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Reply # 874535 9-Aug-2013 12:49

The one in my old car (93 corolla 4pd auto) , locks up at 80 km/h (or is that the trans going into 4th gear ? i'm confused arghh)

If the newer transmissions locks up at most speeds (low to hi) , is this a feature that the manufacturers have put in to save more gas ? (or maybe waste gas since the car actually slows down faster when it locks up since the engine is dragged by the wheels).

Also, if the TC locks and unlocks very often like that, wouldn't it heat up eventually and break ?

vexxxboy

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Reply # 874539 9-Aug-2013 13:02

not sure but does your car have an overdrive system because they can work like an engine break. i know my Toyota does and my car can behave exactly like yours if i play with it around town. Just a thought

Common sense is not as common as you think.

wongtop

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Reply # 874543 9-Aug-2013 13:08

Could also be the fuel cut system that most cars have these days. When the car is decelerating fuel is cut completely to the engine to save fuel. Fuel injection starts again when the engine speed drops to close to idle speed to stop the engine from stalling - this could be the 250 rpm jump that you see. If you've got an instantaneous fuel consumption readout option on your car, this might shed some light - should be 0.0 l/100km when the the fuelling is cut off.

tdgeek

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Reply # 874546 9-Aug-2013 13:13

Sounds like its just changing down a gear as the car decelerates. When it changes down the car will increase rpm and slow down faster, due to the engine brake being applied at the new, lower gear.

coolcat21

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Reply # 874551 9-Aug-2013 13:26

tdgeek: Sounds like its just changing down a gear as the car decelerates. When it changes down the car will increase rpm and slow down faster, due to the engine brake being applied at the new, lower gear.

But my 93 corolla, when you let go of the gas at say 80km/h and then you let it roll/coast to a stop, ....you don't even feel or notice (not even in the rpm) that it's shifting down, no rpm jump. and when it's stopped and you press the gas again, walla it's at 1st gear again...like magic.
But in this new car it's strange

@Wongtop , I think that might be it ? There isn't any mpg meter in the car unfortunately.
Don't all auto cars and cars from the 90s onwards with EFI do thiS ? (turns off spark and cuts fuel when you let go of the gas)

wongtop

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Reply # 874553 9-Aug-2013 13:39

I think most cars do this. My Odessey doesn't do it when the engine is cold and sometimes not when the A/C is on (have instantaneous fuel consumption so can see), but otherwise operates more as you describe in your first post - can defintely feel when the fuel is cut and also when fuelling starts again by the amount of "drag".

tdgeek

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Reply # 874555 9-Aug-2013 13:40

coolcat21:
tdgeek: Sounds like its just changing down a gear as the car decelerates. When it changes down the car will increase rpm and slow down faster, due to the engine brake being applied at the new, lower gear.

But my 93 corolla, when you let go of the gas at say 80km/h and then you let it roll/coast to a stop, ....you don't even feel or notice (not even in the rpm) that it's shifting down, no rpm jump. and when it's stopped and you press the gas again, walla it's at 1st gear again...like magic.
But in this new car it's strange

@Wongtop , I think that might be it ? There isn't any mpg meter in the car unfortunately.
Don't all auto cars and cars from the 90s onwards with EFI do thiS ? (turns off spark and cuts fuel when you let go of the gas)

Mines an 07 Accord Euro. I can just feel the changed down, its not much, pretty gentle, but I can feel it slow down a tad quicker

coolcat21

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Reply # 874568 9-Aug-2013 13:53

wongtop: I think most cars do this. My Odessey doesn't do it when the engine is cold and sometimes not when the A/C is on (have instantaneous fuel consumption so can see), but otherwise operates more as you describe in your first post - can defintely feel when the fuel is cut and also when fuelling starts again by the amount of "drag".

If you coast and let it slow down as much as possible , does the rpm drop slightly below 1000rpm and then suddenly jolts like 200 rpm like the computer is preventing it from stalling ?

That's how it's happening on my car.

I guess i'm not used to these fuel cuts lol.

coolcat21

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Reply # 874569 9-Aug-2013 13:53

tdgeek:
coolcat21:
tdgeek: Sounds like its just changing down a gear as the car decelerates. When it changes down the car will increase rpm and slow down faster, due to the engine brake being applied at the new, lower gear.

But my 93 corolla, when you let go of the gas at say 80km/h and then you let it roll/coast to a stop, ....you don't even feel or notice (not even in the rpm) that it's shifting down, no rpm jump. and when it's stopped and you press the gas again, walla it's at 1st gear again...like magic.
But in this new car it's strange

@Wongtop , I think that might be it ? There isn't any mpg meter in the car unfortunately.
Don't all auto cars and cars from the 90s onwards with EFI do thiS ? (turns off spark and cuts fuel when you let go of the gas)

Mines an 07 Accord Euro. I can just feel the changed down, its not much, pretty gentle, but I can feel it slow down a tad quicker

Ah , i guess these new cars aren't as smooth shifting as the 90s gem then.

CVT ftw !

stevenz

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Reply # 874570 9-Aug-2013 13:54

coolcat21:
Oh and also , when I press the power window button to roll it up , halfway up it makes a clunk sound (like if someone throws a small stone at your window) , ......it doesn't stop it or slow it down, just makes that noise, and a slight grind sound. The other 3 windows roll up/down like butter.

My Alfa does a similar thing, if you don't feel like taking the door to pieces and sorting it out properly (can be simple or a massive PITA depending on the car) then you might be able to stick the long nozzle from a can of CRC\WD40 down beside the window and spray it about.

This might've been caused by someone locking their keys in the car and the mechanism getting damaged by someone using a pry bar to try and disengage the locking mechanism to open the door. My old Mirage had similar issues and it was surprisingly expensive to get sorted out in the end as someone had tried bodging it.

@KnightNZ

coolcat21

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Reply # 874581 9-Aug-2013 14:06

stevenz:
coolcat21:
Oh and also , when I press the power window button to roll it up , halfway up it makes a clunk sound (like if someone throws a small stone at your window) , ......it doesn't stop it or slow it down, just makes that noise, and a slight grind sound. The other 3 windows roll up/down like butter.

My Alfa does a similar thing, if you don't feel like taking the door to pieces and sorting it out properly (can be simple or a massive PITA depending on the car) then you might be able to stick the long nozzle from a can of CRC\WD40 down beside the window and spray it about.

This might've been caused by someone locking their keys in the car and the mechanism getting damaged by someone using a pry bar to try and disengage the locking mechanism to open the door. My old Mirage had similar issues and it was surprisingly expensive to get sorted out in the end as someone had tried bodging it.

I have one of those door hinges spray thing at home, will that do ?
also,
If i don't do anything to it , will it eventually stress the glass and crack it .....or ....kills the motor and window regulator.

fk i hate my dealer.

stevenz

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Reply # 874597 9-Aug-2013 14:27

Door hinge spray is probably similar to CRC, might be silicon-based instead but should do the same job.

The glass isn't likely to be the issue unless it's sticking in the tracks (in which case silicon spray in the tracks will help, don't use CRC unless you like the smell though, silicon spray is magic). If the mechanics are wearing then it'll only get worse, but it might be years until it fails totally, or it could pack up next week, hard to tell.

I can't imagine the door skin on a Corolla being too hard to take off, but it depends on what the access is like behind it, most cars just have a full metal plate behind the skin to reduce noise, some have port holes for wiring etc though, luck of the draw.

@KnightNZ

coolcat21

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Reply # 874606 9-Aug-2013 14:51

stevenz: Door hinge spray is probably similar to CRC, might be silicon-based instead but should do the same job.

The glass isn't likely to be the issue unless it's sticking in the tracks (in which case silicon spray in the tracks will help, don't use CRC unless you like the smell though, silicon spray is magic). If the mechanics are wearing then it'll only get worse, but it might be years until it fails totally, or it could pack up next week, hard to tell.

I can't imagine the door skin on a Corolla being too hard to take off, but it depends on what the access is like behind it, most cars just have a full metal plate behind the skin to reduce noise, some have port holes for wiring etc though, luck of the draw.

Sorry for being dumb, but how can i tell if it's sticking in the tracks or not ?
And is silicon spray expensive ?

Hoofhaarted

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Reply # 874614 9-Aug-2013 15:04

Have you check the manual, it might actually be WAI.

The Old mans mitsi did somthing similar, if you were just cruising around town, and tried to let it just coast down an incluine, it would slow you down, using the engine etc.

But on the open road, assuming you had been going that much faster, it never did it.

Some sort of active engine management, that tried to anticipate how you had been drinving, and mimic it.

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