2015 Tahoe LT 4WD Sluggish Acceleration

[rb5064]

I had a 1999 Tahoe 2WD and I don’t remember ever worrying about merging into traffic with it. I pressed the gas, and it would get up and go. It would put you back in the seat.

I have a 2015 Tahoe LT 4WD with the 5.3 now. It seems to have no acceleration at all. If I floor it, it will not put you in the seat at all.

It gets up to speed in due time, but it just doesn’t have the feel that inspires confidence when jumping on the highway.

There are times, especially the first startup of the day, when I can press the accelerator and it barely moves. It acts like a manual transmission in too high of a gear attempting to accelerate minus the shuddering. Like it’s waiting for the RPMs to increase. Almost got rear ended a few times when that happened.

Overall, the acceleration has left a lot to be desired.

Any suggestions on how to correct or improve this? I added a K&N air filter, otherwise I haven’t done anything else to it yet. I just bought it about 6 months ago.

Thanks in advance!

 

[mb1500]

I’m thinking less of performance upgrades and more of something is wrong with the engine or transmission.

 

[Doubeleive]

@BlackBearPerf

 

[the 18th letter]

I dont notice too much difference between my 99 and 15 when merging onto the highway.

 

[rb5064]

I’m thinking less of performance upgrades and more of something is wrong with the engine or transmission.

My ‘99 didn’t have the active fuel management dropping from 8 cylinders to 4, so I don’t know if that is the difference it not.

It almost seems like it is stuck in 4 cylinder mode when I’m demanding all 8. Not sure how I can test that theory.

My 300c has a HEMI with active fuel management. When I step on it, it jumps to work. The stats on this Tahoe don’t seem to match with the performance.

 

[rb5064]

I dont notice too much difference between my 99 and 15 when merging onto the highway.

Ok. That’s concerning. There is a definite difference between mine.

 

[the 18th letter]

Ok. That’s concerning. There is a definite difference between mine.

I wouldnt be concerned by that alone because there's other factors to consider such as driving styles. I dont get either one to the floor unless I'm already cruising and get 'daylight' to move them.

 

[the 18th letter]

My ‘99 didn’t have the active fuel management dropping from 8 cylinders to 4, so I don’t know if that is the difference it not.

It almost seems like it is stuck in 4 cylinder mode when I’m demanding all 8. Not sure how I can test that theory.

My 300c has a HEMI with active fuel management. When I step on it, it jumps to work. The stats on this Tahoe don’t seem to match with the performance.

I have the AFM disabled, might be making more of a difference that I realized. I got a disabler as soon as I got my 15.

 

[rb5064]

I have the AFM disabled, might be making more of a difference that I realized. I got a disabler as soon as I got my 15.

I didn’t know that was a possibility. I will look into it. How does that affect fuel economy? I’m currently averaging 16 mpg. I drive 90% highway at 85 mph.

 

[swathdiver]

I have a 2015 Tahoe LT 4WD with the 5.3 now. It seems to have no acceleration at all. If I floor it, it will not put you in the seat at all.

There are times, especially the first startup of the day, when I can press the accelerator and it barely moves. It acts like a manual transmission in too high of a gear attempting to accelerate minus the shuddering. Like it’s waiting for the RPMs to increase. Almost got rear ended a few times when that happened.

Acts like it has a 3000 stall converter and 2.73 gears! You may have a pump/torque converter issue.

@NickTransmissions