2015 A8 Base Transmission Issues
Thread Starter
Former Vendor
Joined: Mar 2003
Posts: 18,666
Likes: 395
From: Tampa FL
St. Jude Donor '07-'08-'09-'10-'11-'12'-'13-'14-'15
2015 A8 Base Transmission Issues
Has anyone had this happen and was able to figure it out.
Initial incident- cruising at about 20mph in D, went part throttle and hit the rev limiter, let out of the gas and went part throttle again. Approximately two miles down the road it was like all propulsion was gone. Pulled over on the side of the highway and shut it off. Turned it back and and the car acted fine for about 30-45 seconds then lost complete propulsion again. I repeated the shut down with 10 second wait and again the car shifted and ran fine for 30-45 seconds.
Since then I have repeated this about 10 times. Car goes limp, I shut engine off and move lever to P or N and it runs fine for 30-45 seconds then goes limp. I imagine if this was a transmission or converter issue it would not be so predictable and repeatable. It also affects all gears equally and is the same in either Auto or Manual mode.
There is no Check Engine light or other identifiable code.
Initial incident- cruising at about 20mph in D, went part throttle and hit the rev limiter, let out of the gas and went part throttle again. Approximately two miles down the road it was like all propulsion was gone. Pulled over on the side of the highway and shut it off. Turned it back and and the car acted fine for about 30-45 seconds then lost complete propulsion again. I repeated the shut down with 10 second wait and again the car shifted and ran fine for 30-45 seconds.
Since then I have repeated this about 10 times. Car goes limp, I shut engine off and move lever to P or N and it runs fine for 30-45 seconds then goes limp. I imagine if this was a transmission or converter issue it would not be so predictable and repeatable. It also affects all gears equally and is the same in either Auto or Manual mode.
There is no Check Engine light or other identifiable code.
Instructor
Joined: Jul 2015
Posts: 210
Likes: 32
From: Raleigh
Has anyone had this happen and was able to figure it out.
Initial incident- cruising at about 20mph in D, went part throttle and hit the rev limiter, let out of the gas and went part throttle again. Approximately two miles down the road it was like all propulsion was gone. Pulled over on the side of the highway and shut it off. Turned it back and and the car acted fine for about 30-45 seconds then lost complete propulsion again. I repeated the shut down with 10 second wait and again the car shifted and ran fine for 30-45 seconds.
Since then I have repeated this about 10 times. Car goes limp, I shut engine off and move lever to P or N and it runs fine for 30-45 seconds then goes limp. I imagine if this was a transmission or converter issue it would not be so predictable and repeatable. It also affects all gears equally and is the same in either Auto or Manual mode.
There is no Check Engine light or other identifiable code.
Initial incident- cruising at about 20mph in D, went part throttle and hit the rev limiter, let out of the gas and went part throttle again. Approximately two miles down the road it was like all propulsion was gone. Pulled over on the side of the highway and shut it off. Turned it back and and the car acted fine for about 30-45 seconds then lost complete propulsion again. I repeated the shut down with 10 second wait and again the car shifted and ran fine for 30-45 seconds.
Since then I have repeated this about 10 times. Car goes limp, I shut engine off and move lever to P or N and it runs fine for 30-45 seconds then goes limp. I imagine if this was a transmission or converter issue it would not be so predictable and repeatable. It also affects all gears equally and is the same in either Auto or Manual mode.
There is no Check Engine light or other identifiable code.
Did you ever switch to e85? I know you talked about possibly doing so.
Eric
Thread Starter
Former Vendor
Joined: Mar 2003
Posts: 18,666
Likes: 395
From: Tampa FL
St. Jude Donor '07-'08-'09-'10-'11-'12'-'13-'14-'15
Nope, trans fried. The car has been flaring since 300 miles on the clock. I thought it was just the way the C7 was since so many were talking about quirky shifts. It became worse over time and on hard launches would flare, sometimes to the rev limiter, from 2-3 and 3-4 shift. GM took it apart today.............burnt fluid and metal in the case. I thought the fluid may be low and that flaring on hard launch was cavitation of fluid. Nope just good old slippage
Burning Brakes
Joined: Apr 2016
Posts: 864
Likes: 326
Take it in asap. Your burning up the clutches. I met you at the track in Fayetteville. Ive had 3 trans put in since then. Car is on its 4th now, i have 8900 miles on the car. Pm if you want my phone number i can tell you what i all ive learned.
Did you ever switch to e85? I know you talked about possibly doing so.
Eric
Did you ever switch to e85? I know you talked about possibly doing so.
Eric
Instructor
Joined: Jul 2015
Posts: 210
Likes: 32
From: Raleigh
Lol, they should! Hopefully this one makes it. I disabled e85 so hopefully that will fix it for me. Sucks to lose the power but it seems like the culprit. Wont know until i get this trans to go past 2000miles. And some more testing.
Team Owner
Joined: Aug 2000
Posts: 24,099
Likes: 1,327
From: Spring Texas
By E85 are you talking about E85 gasoline? I think the user manual says nothing above E15.
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Team Owner
Joined: Aug 2000
Posts: 24,099
Likes: 1,327
From: Spring Texas
You also need a lesson in economics of gasoline. Unfortunately for consumers, ethanol is sold on the marketplace as a gasoline extender and is not priced according to its energy content but relative to the price of normal gasoline. As a result, E85 is prices waaaaaayyyyyy tooooooo high with respect to its energy content (miles per gallon capability).
If gasoline without any ethanol is $2.00, then E10 should sell for $1.93, E15 for $1.90, and E85 for $1.44 based solely on energy content. Around here, if E10 is $1.95 then E85 is generally $1.75 or so, not nearly enough of a discount to offset the mileage loss.
Last edited by CP; May 28, 2016 at 07:17 PM.
Instructor
Joined: May 2012
Posts: 227
Likes: 14
From: Houston TX
E85 can't affect the transmission, let's be real here. If the extra 30hp that E85 makes is what causes the trans to burn up then I'd have to say either way the trans is or was gonna fail GM has their hands full right now on this A8.
Last edited by Spulbus2013; May 28, 2016 at 07:36 PM.
Burning Brakes
Joined: Apr 2006
Posts: 758
Likes: 15
From: burlington north carolina
Lmao... The extra 10-15 hp e85 is adding on a "bolt on" setup has nothing to do with nor the culprit of the tranny no way no how no shape or form... Also no one is using e85 on a vette for mileage.
Last edited by kiley2418; May 28, 2016 at 07:52 PM.
Race Director
Joined: Jul 2007
Posts: 10,959
Likes: 2,641
From: Texas Hill Country
How would that affect the transmission?
You also need a lesson in economics of gasoline. Unfortunately for consumers, ethanol is sold on the marketplace as a gasoline extender and is not priced according to its energy content but relative to the price of normal gasoline. As a result, E85 is prices waaaaaayyyyyy tooooooo high with respect to its energy content (miles per gallon capability).
If gasoline without any ethanol is $2.00, then E10 should sell for $1.93, E15 for $1.90, and E85 for $1.44 based solely on energy content. Around here, if E10 is $1.95 then E85 is generally $1.75 or so, not nearly enough of a discount to offset the mileage loss.
You also need a lesson in economics of gasoline. Unfortunately for consumers, ethanol is sold on the marketplace as a gasoline extender and is not priced according to its energy content but relative to the price of normal gasoline. As a result, E85 is prices waaaaaayyyyyy tooooooo high with respect to its energy content (miles per gallon capability).
If gasoline without any ethanol is $2.00, then E10 should sell for $1.93, E15 for $1.90, and E85 for $1.44 based solely on energy content. Around here, if E10 is $1.95 then E85 is generally $1.75 or so, not nearly enough of a discount to offset the mileage loss.
Around here:
E10 87, which you should not be using in a corvette is 2.05
E10 89, which you should not be using in a corvette is 2.24
E10 93, which you should be using is 2.42
E85 is 1.65
93 vs E85 price difference is 32% cheaper for E85 which offsets the mileage difference AND you get what is basically race gas with respect to detonation resistance and power production.
Race gas is $14/gallon so you tell me if E85 isnt a no-brainer!
Instructor
Joined: Jul 2015
Posts: 210
Likes: 32
From: Raleigh
The problem i was having is the engine and trans communicating properly. Engine tells trans 500tq trans only read it as 200tq causing the clutches to slip because not enough pressure applied. Not 100% sure as to why, just i can tell you that 2 trans out 3 didnt shift correctly and burned up under 1600 miles. I stopped using e85 and haven't had a problem yet. Once the trans makes it past 2000 miles i will try e85 again.
Dont need a economic lesson im good. Its for going to the track and when trolling for trouble only and i can get it as cheap as 1.24 at the local sheetz.
Dont need a economic lesson im good. Its for going to the track and when trolling for trouble only and i can get it as cheap as 1.24 at the local sheetz.
Thread Starter
Former Vendor
Joined: Mar 2003
Posts: 18,666
Likes: 395
From: Tampa FL
St. Jude Donor '07-'08-'09-'10-'11-'12'-'13-'14-'15
Trans replaced at the AWESOME dealership you pointed me to brother. Thanks
New trans had wiring issue, they had to pull it again, repair and the car will be ready for the road on MONDAY! Hells yeah, cant wait. REALLY appreciate your help on this. You know you got my marker for any parts you need for your ride
Cajun
New trans had wiring issue, they had to pull it again, repair and the car will be ready for the road on MONDAY! Hells yeah, cant wait. REALLY appreciate your help on this. You know you got my marker for any parts you need for your ride
Cajun
Instructor
Joined: Jul 2015
Posts: 210
Likes: 32
From: Raleigh
Trans replaced at the AWESOME dealership you pointed me to brother. Thanks
New trans had wiring issue, they had to pull it again, repair and the car will be ready for the road on MONDAY! Hells yeah, cant wait. REALLY appreciate your help on this. You know you got my marker for any parts you need for your ride
Cajun
New trans had wiring issue, they had to pull it again, repair and the car will be ready for the road on MONDAY! Hells yeah, cant wait. REALLY appreciate your help on this. You know you got my marker for any parts you need for your ride
Cajun
I'll be in touch with you. I want a blower for my car bad! Just want to give my trans some more time before i feel comfortable adding more power.
Look forward to seeing you at the track again
Hit me up next time you go.
Eric