Weird Sound. Please Help.

[Joseph92]

I have the L99 engine with the automatic transmission. Stock Tune.

The issue I am having is this:
When driving and using the paddle shifters in manual mode. I would be at a complete stop and in first gear and as I accelerate and shift from 1st into 2nd, I get this sound that kinda sounds like pressure being released or like something is slipping (kinda like both at the same time). The sound is coming from the center of the car in the transmission area. The sound also varies in tone and length depending on the RPM (in 1st gear) when I shift into 2nd gear. (Example: In 1st gear at 4500RPMs I change to 2nd gear, the sound might last longer and be louder VS. in 1st gear at 3000RPMs and changing to 2nd gear.) I am only experiencing this when switching from 1st - 2nd gear. And if I where to give you a ratio of how often I can make it happen is about 8 times out of 10.

I have heard this sound in the past while in drive mode, but did not think much about it because it would happen so rarely. I am concerned now because after using the paddle shifters I finally pin pointed how to make the sound appear. I did not notice this earlier because I rarely use the paddle shifters.

[Joseph92]

I wanted to add something else to my first post:

The other day while driving I noticed that the sound, when loud sounds more like it is inside the cab vs. when it is not as loud it sounds like it is both inside and outside the cab. However, either way the sound seems to generate from the front of the center console underneath the four gauges, somewhere in that general area and that it happens when switching from 1st gear to 2nd gear in paddle shifter mode and sometimes in drive mode.

I am not sure what the found is from. I just know that it happens under those circumstances as described above.

[Joseph92]

Just to give an update.

I went to the dealer over the weekend to have this issue looked at. Good news is they say that it is not the transmission.

However, they think it might be the throttle body fluttering or some type of actuator. (The funny thing is that it only does it when switching from 1st gear to 2nd gear.)

They told me to put my stock air intake back on that way they can eliminate that as being a possible cause. It will be a few weeks maybe even next month before I will have the time to change the intake out and send it back to the dealer.

Still any advice would help.

Thank you

[Joseph92]

Just to give an update.

I went to the dealer over the weekend to have this issue looked at. Good news is they say that it is not the transmission.

However, they think it might be the throttle body fluttering or some type of actuator. (The funny thing is that it only does it when switching from 1st gear to 2nd gear.)

They told me to put my stock air intake back on that way they can eliminate that as being a possible cause. It will be a few weeks maybe even next month before I will have the time to change the intake out and send it back to the dealer.

Still any advice would help.

Thank you

[Joseph92]

Originally Posted by Joseph92

Just to give an update.

I went to the dealer over the weekend to have this issue looked at. Good news is they say that it is not the transmission.

However, they think it might be the throttle body fluttering or some type of actuator. (The funny thing is that it only does it when switching from 1st gear to 2nd gear.)

They told me to put my stock air intake back on that way they can eliminate that as being a possible cause. It will be a few weeks maybe even next month before I will have the time to change the intake out and send it back to the dealer.

Still any advice would help.

Thank you

Sorry I don't know why that posted twice.

[Joseph92]

Any advice. Please.