WHY YOU DO THIS? - Page 2 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

GretchenGotGrowl · 08-07-2015, 07:01 AM

Quote:

Originally Posted by JohnyBoy

Hey all,

I hit the local drag strip tonight in my auto 2014 ZL1, First two passes were good (ptm 5, transmission in "m" for sport mode) On the third pass however, about 2 seconds after slamming the gas the throttle response was gone and it revved all the way up to the redline. My car was dead in the water, while limping off the track I put it back into the "D" position, it lunged hard and returned to normal operations. I made 5 passes afterwards with the shifter in "D" and aside from wheel spin all was well. Why the hell did my car do this? I always baby it and never abuse it..

Is it possible you accidently hit the paddle shifter? That would have put it into manual mode and then you could bounce off the redline. It is hard to say without more description. Was this right off the line or after it had shifted to second or third? On the final 5 passes did you notice just one wheel spinning? How long did it rev to redline? A brief time or for several seconds?

Norm Peterson · 08-07-2015, 07:02 AM

Sounds like the PCM basically threw the transmission into neutral or something inside the transmission failed. It is entirely possible for an AT to either work just fine in full automatic mode but not in manual mode, or vice versa, if slightly different combinations of bands and clutches is used.

Is there any chance at all that you didn't get it solidly into 'M', or that the shifter was able to move out of 'M' somehow?

Either way, it needs to be looked at.

Norm

christianchevell · 08-07-2015, 07:04 AM

torque management maybe killing it.....

Denis · 08-07-2015, 07:09 AM

Quote:

Originally Posted by JohnyBoy

But why would the car coast down to almost a stop just to keep revving at the redline when I would try to accelerate?

Quote:

Originally Posted by JohnyBoy

And not move until I put it back into "d"

ooooh i guess I missed that.

yea that sounds pretty odd...

JohnyBoy · 08-07-2015, 07:11 AM

It happened a couple seconds after take off, probably was in second or third at that point. And no, I didn't accidentally hit a paddle shift. But hypothetically speaking wouldn't an accidental shift be denied at the rate I was going?

GretchenGotGrowl · 08-07-2015, 07:28 AM

Quote:

Originally Posted by JohnyBoy

It happened a couple seconds after take off, probably was in second or third at that point. And no, I didn't accidentally hit a paddle shift. But hypothetically speaking wouldn't an accidental shift be denied at the rate I was going?

I was thinking more along the lines of you are in first and accidently upshift (so you are no in third) and then it doesn't shift to third automatically because you are now in manual mode.

What about the burn outs? Was only one wheel spinning after this happened?

JohnyBoy · 08-07-2015, 07:34 AM

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I completely skipped the water box because I didn't want to burn my stock tires. For all the passes I made before and after this happened there was severe wheel spin, probably because I didn't adjust tire pressure. I kept the car in ptm mode 5 the entire night.

JohnyBoy · 08-07-2015, 07:36 AM

I'm not sure if during the wheel spin only one was spinning or both. It jumped a little to the left each time there was wheel spin before hooking up.

GretchenGotGrowl · 08-07-2015, 07:41 AM

Quote:

Originally Posted by JohnyBoy

I'm not sure if during the wheel spin only one was spinning or both. It jumped a little to the left each time there was wheel spin before hooking up.

Check it by seeing doing a burnout in a empty parking lot. If you leave one mark it is likely a clutch in the differential gave out (or worse). That could result in enough feedback to the transmission to "knock" it out of gear like Norm is saying. Wheel hop is a Biatch!

JohnyBoy · 08-07-2015, 07:54 AM

No chance the shifter moved out of place or wasn't securely in place. But I agree with Norm, the car behaved like it was thrown into neutral some how.

GretchenGotGrowl · 08-07-2015, 07:57 AM

Quote:

Originally Posted by JohnyBoy

No chance the shifter moved out of place or wasn't securely in place. But I agree with Norm, the car behaved like it was thrown into neutral some how.

Not so much the shifter as the transmission itself disengaging clutches that made it act like it was in neutral.

SlingShot · 08-07-2015, 08:59 AM

Could be an issue with only 1st gear, seeing Drive starts in 2nd gear. You would have to test it running in Sport mode to see if 1st is slipping.

WoodBoss · 08-07-2015, 09:19 AM

Sounds like a transmission problem.

JohnyBoy · 08-07-2015, 10:25 AM

Well I'm pretty positive that the clutch had been dis engaged, that would explain the red line revving and lack any forward motion. Gonna swing by the dealer today to book my appointment.

08-07-2015, 07:02 AM	#16
Norm Peterson corner barstool sitter Drives: 08 Mustang GT, 19 WRX Join Date: Jul 2012 Location: Eastern Time Zone Posts: 6,990	Sounds like the PCM basically threw the transmission into neutral or something inside the transmission failed. It is entirely possible for an AT to either work just fine in full automatic mode but not in manual mode, or vice versa, if slightly different combinations of bands and clutches is used. Is there any chance at all that you didn't get it solidly into 'M', or that the shifter was able to move out of 'M' somehow? Either way, it needs to be looked at. Norm __________________ '08 GT coupe 5M (the occasional track toy) '19 WRX 6M (the family sedan . . . seriously)

08-07-2015, 07:04 AM	#17
christianchevell old school chevy rodder Drives: 2013 2SS/RS Manual,DM exhaust,CRT Join Date: Jul 2012 Location: Oregon Posts: 5,587 View My Garage	torque management maybe killing it..... __________________ 2021 Wild Cherry ZL1 A10, Sunroof, Data, Carbon, Nav, RotoFab Dry CAI, Elite x2, Borla ATK, Driveshaft shop

08-07-2015, 08:59 AM	#26
SlingShot Drives: 2012 ZL1 - #670 Join Date: Jun 2009 Location: Seminole, Fl. Posts: 8,009	Could be an issue with only 1st gear, seeing Drive starts in 2nd gear. You would have to test it running in Sport mode to see if 1st is slipping. __________________

08-07-2015, 07:11 AM	#19
JohnyBoy Drives: GM car Join Date: Jul 2014 Location: North America Posts: 49	It happened a couple seconds after take off, probably was in second or third at that point. And no, I didn't accidentally hit a paddle shift. But hypothetically speaking wouldn't an accidental shift be denied at the rate I was going?

08-07-2015, 07:34 AM	#21
JohnyBoy Drives: GM car Join Date: Jul 2014 Location: North America Posts: 49	I completely skipped the water box because I didn't want to burn my stock tires. For all the passes I made before and after this happened there was severe wheel spin, probably because I didn't adjust tire pressure. I kept the car in ptm mode 5 the entire night.

08-07-2015, 07:36 AM	#22
JohnyBoy Drives: GM car Join Date: Jul 2014 Location: North America Posts: 49	I'm not sure if during the wheel spin only one was spinning or both. It jumped a little to the left each time there was wheel spin before hooking up.

08-07-2015, 07:54 AM	#24
JohnyBoy Drives: GM car Join Date: Jul 2014 Location: North America Posts: 49	No chance the shifter moved out of place or wasn't securely in place. But I agree with Norm, the car behaved like it was thrown into neutral some how.

08-07-2015, 09:19 AM	#27
WoodBoss "Old School" Drives: 2010 2SS L99 Join Date: Apr 2015 Location: Sherrills Ford, NC Posts: 1,295	Sounds like a transmission problem.

08-07-2015, 10:25 AM	#28
JohnyBoy Drives: GM car Join Date: Jul 2014 Location: North America Posts: 49	Well I'm pretty positive that the clutch had been dis engaged, that would explain the red line revving and lack any forward motion. Gonna swing by the dealer today to book my appointment.