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Trabmission needs more revs after cold start


Psycho

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Hi

I have a question about the transmission of my 99 STS (24k miles).

When I start the Engine in the morning (or when the engine is cold), the car needs about 500 more revs

till the car moves.

When I stop at the first crossroad and drive on, the transmission works as always.

The oil level is o.k. the color of the oil is fine (clear red), no smell, no error codes.....

It don't has any problems, works fine, shifts smooth.

My old 95 STS hasn't had that behavior.

Is that normal on the 99 ?

Any ideas ?

regards Psycho :huh:

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do you let the car warm up before putting it in gear?

Wiz DRIVE IT LIKE YOU own it!!!!!! 1967 chevy II ( FOR SALE!!!!) 1995 Lexus Es 300 1998 SLS

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Hi wiz

no, I start the car, put it into "D" and drive.

About 10s after engine start.

Psycho B)

TRY LETTING IT WARM UP A LITTLE BIT & SEE IF THAT HELPS

Wiz DRIVE IT LIKE YOU own it!!!!!! 1967 chevy II ( FOR SALE!!!!) 1995 Lexus Es 300 1998 SLS

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Are there any OBD II codes? Here's how to get them:

http://www.caddyinfo.com/readingcodes.html

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-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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@wiz... I will try tomorrow

@Jims_97_ETC... no, I checked it in the car and with a scan software.

As I wrote this happens only the first time, I start driving at cold conditions.

If I drive a few meters, stop, shift to neutral and back to "D" again, everything is o.k.

There is no slip or unusual behavior.

And it only happens on time at cold engine/transmission.

regards Psycho :)

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If the transmission fluid has never been changed, there may be a little sticking. If the fluid passes the smell and appearance tests. getting the transmissoin serviced will likely do the trick. The mileage is low but eight years is a long time. A transmission service and a good long drive will get the juices flowing like new.

There is a possibility that this is normal. On startup, the PCM operates with a bunch of defaults and runs the transmission and engine in open-loop fashion like a car in the 1970's. As soon as all its sensors are logged in, things get a little more intelligent. The driver's profile for your fob may be more conservative than your 1995's PCM thought that you were.

CTS-V_LateralGs_6-2018_tiny.jpg
-- Click Here for CaddyInfo page on "How To" Read Your OBD Codes
-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data
-- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC
Yes, I was Jims_97_ETC before I changed cars.

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If the transmission fluid has never been changed, there may be a little sticking. If the fluid passes the smell and appearance tests. getting the transmissoin serviced will likely do the trick. The mileage is low but eight years is a long time. A transmission service and a good long drive will get the juices flowing like new.

There is a possibility that this is normal. On startup, the PCM operates with a bunch of defaults and runs the transmission and engine in open-loop fashion like a car in the 1970's. As soon as all its sensors are logged in, things get a little more intelligent. The driver's profile for your fob may be more conservative than your 1995's PCM thought that you were.

Hmmm.....

transmission fluid has been changed last year and I had several long trips with high speed and high revs in different temperatures (between 32 an 10°C outside temperature).

I recognized another funny thing.... If I start the car and try to drive on, during the speedometer and the rev-display are doing the self test (needles goes from zero to max and back again), the car gets a few temporary errors.

That happend on a 99 STS, that a friend owns a few year ago, too.

I think the PCM does a lot of self testing during the first few seconds.

Maybe someone can test this on the same car...

regards Psycho ;)

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If the transmission fluid has never been changed, there may be a little sticking. If the fluid passes the smell and appearance tests. getting the transmissoin serviced will likely do the trick. The mileage is low but eight years is a long time. A transmission service and a good long drive will get the juices flowing like new.

There is a possibility that this is normal. On startup, the PCM operates with a bunch of defaults and runs the transmission and engine in open-loop fashion like a car in the 1970's. As soon as all its sensors are logged in, things get a little more intelligent. The driver's profile for your fob may be more conservative than your 1995's PCM thought that you were.

Hmmm.....

transmission fluid has been changed last year and I had several long trips with high speed and high revs in different temperatures (between 32 an 10°C outside temperature).

I recognized another funny thing.... If I start the car and try to drive on, during the speedometer and the rev-display are doing the self test (needles goes from zero to max and back again), the car gets a few temporary errors.

That happend on a 99 STS, that a friend owns a few year ago, too.

I think the PCM does a lot of self testing during the first few seconds.

Maybe someone can test this on the same car...

regards Psycho ;)

Update

Today I tried the following:

Start car, let it Idle for about 15 seconds, put transmission into "D" and drive.

Everything was o.k. car moved, after I released the brake, without the need of more throtle.

So I think it is realy a selftest/diagnostic time the car needs.

Thanks to all.

regards Psycho <_<

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Psycho,

Did you experience this again? about 3 days after reading your original post it started to happen to my Eldo as well.

I replaced the fluid about 1.5 month ago (forgot to replace the darn solenoids though!!)

Thanks

Marc.

If you are in complete control..... you are not going fast enough....

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My 98 DeVille has the same issue. If I put it in gear right after starting without ideling for a few seconds, it doesn't want to go right away. None of my previous Northstar cars did this. I have found that it is because there is no fluid in the cooler lines and ideling for 10 or 15 seconds allows the transmission time to build fluid pressure. My 93 Dodge Dakota does it too and I have read that in those, there is a check valve that keeps the lines full of fluid that wears out and allows the lines to drain causing the delay. I don't know for sure but maybe the 4t80e has a similar check valve. It is more of an annoyance than anything. I don't believe it will cause any problems otherwise. Luckily the 4t80e pumps fluid at idle. The Dakota does not and has to be put in gear to pump the fluid. It is one of few transmissions that is that way and the fluid level has to be checked in neutral.

K.O.T.

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I have a shift kit to fix that concern. This is a very common problem and it has to do with the accumulator cover and gasket

12.58 second Northstar with a GM/Cadillac PCM

Cadillac Technician @ Crest Cadillac Brookfield WI

Hometown Washougal WA

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Psycho,

Did you experience this again? about 3 days after reading your original post it started to happen to my Eldo as well.

I replaced the fluid about 1.5 month ago (forgot to replace the darn solenoids though!!)

Thanks

Marc.

Hi

yes, the transmission needs about 5-10s.

I asked my dealer and he said that is a known thing on the STS after 1997, but no error.

regards Psycho :D

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