Torque Converter Clutche Plates Behavior

[4G63T]

When the motor is completely cold (and cold outside temps) , generally when you start the car it will idle high close to 2k rpms for about 20-30 seconds and then drop down to about 1k rpms. Which is normal .

If I let it idle for about 10 seconds only and then start driving, torque converter clutches are not "locking". It will stay this way until close to the blue engine cold light turning off depending in how cold it is outside . Example it's 20 F or 10 F. This is speeds up to 35-40mph , I haven't driven faster than yet to test up to how fast it does this.

So I tested letting the car idle for 20-30 seconds for that drop in rpm to occur , when I start driving the clutches do lock like normal "engine warmed up condition".

Are you noticing the same thing ? I think it's always been this way .

I'm curious maybe it gets stuck in "warm up mode" for the transmission (if there is such thing) when it's really cold and I start driving "early" .

 

[russiankid]

I know mine doesn't fully lock until it is warmed up, but I haven't noticed what you're describing as far as letting the car idle first and it not doing it then.

 

[4G63T]

Actually scratch that about the 20-30 seconds warm up. Our car is garage kept so sometimes when the motor is not driven for couple hours its still not “cold” like parking in the street overnight. So in some cases the RPM’s might idle high (warm up mode) longer and some cases shorter.

So from what you shared, then I guess its normal function of our car that the (AT) clutch plates dont lock up completely until the motor is close to being fully warmed?

I looked in the manual and only thing I found so far is to let it idle for 10 seconds after ignition.

 

[MikeM.]

So from what you shared, then I guess its normal function of our car that the (AT) clutch plates dont lock up completely until the motor is close to being fully warmed?

I know the torque converter either doesn't lock up as often (or perhaps not at all) until certain transmission fluid temperature is reached. It's less efficient to run with the converter un-locked but all of the extra energy is converted to heat which helps the transmission fluid heat up and reach it's most efficient state sooner.

I looked in the manual and only thing I found so far is to let it idle for 10 seconds after ignition.

That's a good rule of thumb with any modern fuel-injected car.

 

[russiankid]

Actually scratch that about the 20-30 seconds warm up. Our car is garage kept so sometimes when the motor is not driven for couple hours its still not “cold” like parking in the street overnight. So in some cases the RPM’s might idle high (warm up mode) longer and some cases shorter.

So from what you shared, then I guess its normal function of our car that the (AT) clutch plates dont lock up completely until the motor is close to being fully warmed?

I looked in the manual and only thing I found so far is to let it idle for 10 seconds after ignition.

Based on what I have observed, that is the behavior. I have noticed this on many AT vehicles.