Tlwarren08
TYF Newbie
- Joined
- Nov 17, 2018
- Posts
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Bear with me as this may get Lengthy.
A few weeks back I started to notice that while driving 35-45mph, I press my accelerator my 2015 LTZ would feel "sluggish" to speed up, it reminds me of a manual car that is cruising in a 6th gear at a very low RPM/mph and it will kinda of "shudder" until it gets the RPMs up for that gear (if that makes sense). I assumed that this is just because it is in V-4 mode (DoD/AFM) and I had not reached the "criteria" to disable DoD and get it back into V8 mode. So after weeks of dealing with it, I finally got to looking at HP tuners and changed it to try and prevent it from happening at 35-45 (this is not a speed based feature, its RPM, MAP, oil Temp, ERT and a bunch of random stuff that really isn't activated based on speed.) So with that the only change I was able to make that I would be aware of is the TPS %. I lowered this valve to disable V-4 much sooner. For a while I felt that this had solved my issue. I would be cruising and press the pedal and not even 1/2second and the sluggishness (shutter sound) would be gone were as previously I could ease in to it, hold it and it would stay in V4 and shudder until it switched to V8. So all was good until about 3 days ago it started the "sluggishness/shuddering" again. Today while driving to the In-laws I get to a stop light and slowing down it gets a pretty bad shudder, jerking the Tahoe. Well that's weird keep driving on, we have about 1hr and a half left. I notice the RPM oscillating pretty drastic 250-500RPM while cruising at 65-80mph, but we make it. When we leave we get about 45 minutes away, and we're hitting V4 a lot because its a lot of down hill cruising and I notice the "sluggishness" is back and way worse. I scroll to the Trans temp, 212* no biggy inter webs say up to 225* is "ok". We get to the rice fields (flat AF roads) I slow down and the temp drops. I go to speed back up and my RPMs go up but I'm not moving and it starts whining temps go back up we maxed at 219* and once w/cruise control set we hit a hill and the RPMs shot up to 6K.....
SO if you're still with me, Have any of you noticed your vehicle being "sluggish"/shuddering on the transition from V4 to V8 mode, or do y'all think it was my transmission having issues from the very beginning?? I bought the vehicle in Dec '17 NEVER noticed the "sluggish"/shudder transition until about 3 months ago!!
We're at 107K miles, no modifications, has trans fluid, I have unfortunately not changed the fluid.
A few weeks back I started to notice that while driving 35-45mph, I press my accelerator my 2015 LTZ would feel "sluggish" to speed up, it reminds me of a manual car that is cruising in a 6th gear at a very low RPM/mph and it will kinda of "shudder" until it gets the RPMs up for that gear (if that makes sense). I assumed that this is just because it is in V-4 mode (DoD/AFM) and I had not reached the "criteria" to disable DoD and get it back into V8 mode. So after weeks of dealing with it, I finally got to looking at HP tuners and changed it to try and prevent it from happening at 35-45 (this is not a speed based feature, its RPM, MAP, oil Temp, ERT and a bunch of random stuff that really isn't activated based on speed.) So with that the only change I was able to make that I would be aware of is the TPS %. I lowered this valve to disable V-4 much sooner. For a while I felt that this had solved my issue. I would be cruising and press the pedal and not even 1/2second and the sluggishness (shutter sound) would be gone were as previously I could ease in to it, hold it and it would stay in V4 and shudder until it switched to V8. So all was good until about 3 days ago it started the "sluggishness/shuddering" again. Today while driving to the In-laws I get to a stop light and slowing down it gets a pretty bad shudder, jerking the Tahoe. Well that's weird keep driving on, we have about 1hr and a half left. I notice the RPM oscillating pretty drastic 250-500RPM while cruising at 65-80mph, but we make it. When we leave we get about 45 minutes away, and we're hitting V4 a lot because its a lot of down hill cruising and I notice the "sluggishness" is back and way worse. I scroll to the Trans temp, 212* no biggy inter webs say up to 225* is "ok". We get to the rice fields (flat AF roads) I slow down and the temp drops. I go to speed back up and my RPMs go up but I'm not moving and it starts whining temps go back up we maxed at 219* and once w/cruise control set we hit a hill and the RPMs shot up to 6K.....
SO if you're still with me, Have any of you noticed your vehicle being "sluggish"/shuddering on the transition from V4 to V8 mode, or do y'all think it was my transmission having issues from the very beginning?? I bought the vehicle in Dec '17 NEVER noticed the "sluggish"/shudder transition until about 3 months ago!!
We're at 107K miles, no modifications, has trans fluid, I have unfortunately not changed the fluid.
