DebRedZR1

Friend on vaca, their A8 in the shop with Limp mode. Anyone have any issues? More details later.

TheRobSJ

Mine has gone into a limp mode a couple times where I got some bad gas and got myself a check engine light after a short pull. Feels like half the power and really runs out of breath around 5000rpm. There are other limp modes that can happen with cars these days though. If something goes bad with the drive by wire throttle, the “limp mode” for that will just keep the car at a high idle.

DebRedZR1

^^^^ Thank you, They made it home and to a local Dealership. One trans code that won’t clear.

Repo Pilot

Good luck. I have the same problem with the overheat plus its been in 5 times for it. So the dealer had GM revoked my drivetrain warranty over the phone for stuff like using spark plugs and spark-plug wires that were not a Delco product and a other crap like non-gm x-pipe and Akrapovic mufflers and tips. I never realized how parts like that can make your transmission overheat and activate limp mode.

OK - So without question I can lemon law them. But what can I replace it with? A C8-ZR1??

You don't want to know just how much that pisses me off to have a dealer that I've bought 3 Corvettes and 3 Grocery Getters from not tell the complete truth to GM and pull this kind of **** off. I simply do not understand why GM refuses even to review what took place as the dealer did not accurately describe the situation and GM refused to send the rep out to the shop to look at the car and discuss the history of the problem.

Meantime, according the Redline Automotive who moved from New York to South Florida and who only works on GM products and builds/tunes cars that excel in straight line racing knows the problem well says that they can replace the torque converter and solve the problem for under 5 grand.

Jeff V.

I'm not saying I agree with their decision, but your car does have performance modifications. They're within their rights to void your powertrain warranty. If the exhaust is shedding more heat, then yeah, it could possibly cause your trans to run hot.

I doubt the dealership "had GM" do anything. They have to check for mods when they put in the warranty claim. GM saw that and said no uh uh. It's standard operating procedure. You're not going to find a lawyer who will take it as a lemon law case with that knowledge either.

Repo Pilot

Read my lips Jeff. The dealer had tried to resolve the slipping torque converter working with GM many times including the flush. After the flush the dealer assured me that if the flush didn't work that GM had told them they would replace the transmission. In test driving the car they were able to duplicate the slip and document it with their computer by turning on the cruise control a 75 and letting the car stabilize...then clicking the speed up control 8 or 10 times. The RPM, which was already low as were were in 8th gear, increased 500 + rpm as the transmission slipped like hell and it slowly slipped itself up to speed. GM has that on file and its why they agreed to replace the transmission if the flush didn't work.

Finally, over the entire period the dealer tried to chase down this problem nothing changed in the configuration of the car. And neither the ECM, sensors or any other module was cracked or modified.

Therefore car is NOT tuned. And please tell me where there is anything in the owner's manual that says anything that is replaced that is not a GM or Delco part will void your warranty. It's full of all sorts or other cautions but not that one. The car has the GM X-pipe in it and there are no loose connections so your concern about a hotter and/or leaking exhaust is not a factor.

If I told you I replaced the stock wheels with a set of Forgelines would you tell me that doing so would also cause GM to cancel covering a brake or suspension problem? What about the guys who are not using Michelin tires? Are they putting their warrantee at risk too?

Finally this transmission has a horrible history of slipping and overheating on every car that GM has put it on as far as I know starting with the Z06 and continuing to the ZR1 and also the Cadillac. Its not a problem on most of them but it sure as hell is a problem on my car and has been one since day 2.

By chance, do you work for GM? If so, I'd love to continue this discussion off-forum.

Cheers - Kevin

Jeff V.

No, I don't work for GM.

The warranty is for the stock car, as they built it. So yeah, they could refuse to cover a suspension issue for modded wheels. As I said, I don't agree with it or even really like it. But it is what it is.

From: https://gm-techlink.com/?p=9871

Titanium radiates heat differently than the stamped steel stock exhaust. It's got less sound deadening material too. So the heat profile is going to be different. Different enough to cause a trans problem? I have no idea. But it's plausible enough that they can probably waste a lot of your time and money in court over it.

SouthernSon

Repo, I feel your pain. I have felt the same pain to a lesser extent. 3/4 ton GMC had headlight problem, no bright beam. I took it to the dealership from whom I bought it. Shop foreman called and said they would not work on it because it looks as though I have added a leaf spring. Truck is exactly as I bought it new and drove it out of their lot. GM will lose business from me in the future (and have) until this shoddy service policing of their dealerships improves ..... GREATLY! Never tried Audi so I bought the A8L from dealer last Fall. So far I like their attitudes and appreciation of patronage. Quite frankly, I may never buy another GM product.

Deb, tell your friend to unhook both battery cables and touch them together for 12 seconds to fully discharge any residual in capacitors. Put cables back on battery and see if all is well once again. A GM engineer showed me that trick at the track when DIC said see dealership for A/H issue. Problem was cleared right up at the track.

TheRobSJ

I assume since you’ve possibly explored lemon law buyback process you’ve come across the gist of the Magnusson-Moss Warranty Act? But maybe you haven’t so I’ll lay out the broad strokes here. Your warranty can not be voided if you used non GM branded parts. Your warranty can not be void unless they can prove your modifications caused the failure.

So spark plugs and wires are quite frankly, all the same. They either work and you get a spark that ignites the air-fuel charge in the combustion chamber, or they don’t. One could argue that a different heat range plug or wires with slightly different resistance than the OE parts could possibly cause a misfire under very certain conditions.

Now here’s where things get a bit sticky. I quoted two different posts from you here. I don’t know if you do or do not have the stock X-pipe. Aftermarket spark plugs are one thing, and to be honest so are mufflers…little to no power gain. But if you do in fact have an aftermarket X-pipe (and if it’s like all the others it eliminates the secondary cats), then you have a bonafide power adder. Sure we could play the angle of the change in heat radiating from the exhaust “burned” the transmission and failed the torque converter. But we both know that’s absurd and not true. The card they would play? GM could argue in court, and win, that the additional power now being input to the transmission goes beyond the specifications originally designed for it to handle. Therefore they are no longer liable to cover any powertrain failures.

My last couple years working for Acura, I started taking in NSXs and doing powertrain modifications. At the dealer doing modifications that would probably void their warranty. I made all my clients acknowledge and sign that powertrain modifications were not sanctioned by American Honda or my dealership and any failures that were to result of said modifications may not be covered by their vehicle’s warranties. And then I gave them a wink and said, hey if there’s a problem you come back straight to me and I’ll do my best to look the other way. But if something really major blows up (like a $35k transmission or something along those lines), be prepared to pay to strip everything off and put it back to stock before I try and claim anything under warranty. And if I should be gone, which is the case, or they are no longer in the area and have to take the car somewhere else? Say the words Magnusson-Moss Warranty Act if the dealer all of a sudden doesn’t want to cover their power window not working just because they found the methanol injection kit I put on their engine.

So the long and short of it is, if you do in fact have an aftermarket x-pipe, and that went into “the record” with GM, I think you’re stuck with it. If you’re still stock there? I honestly don’t see how there’s any extra strain on your transmission and torque converter. And you have a shot of lawyering up and making them fix it with the M-M Act.

Hib Halverson

In defense of the 8L90 and it's little brother the 8L45, I have two if the former and one of the latter.

2016 ATS-V w. 8L90. One problem in 63,000 mi. Trans temp. sensor went bad and was replaced under warranty
2019 ZR1 w. 8L90. Trouble free for just under 30,000 miles
2918 Colorado w. 8L45. Trouble free for 12,000 miles.

Not denying that the 8L90 is universally trouble-free but my experience has been good.

17 Z06/Z07

Repo pilot: Maybe the buyer in that auction was looking for the faster of the two ZR1-ZTK drivetrain models that were produced.LOL I repeat the auto-trans in the ZR1 is NOT up to par with the rest of the car and GM knew it.....

Repo Pilot

You got lucky Hib. Meantime I can do that cruise control slip demonstration all day long, and I can fix it with an aftermarket torque convertor.

Repo Pilot

No argument there sir. Thankfully only a small percentage of them have this slip problem but sure as hell GM knew there were sporadic problems with it when they put it on the ZR1. They learned about it on the Z06. And they whent on to put it on Cadillacs only to have the same problem and that pretty much eliminates the contention that the reason it slips is because of the mega-power the ZR is putting down..

JG61354

I have had zero issues with the transmission on mine (13,000 miles). I guess it’s luck but I’ve had it at Sebring 4 or 5 times and once at Homestead and it performed flawlessly. This is typically in the high 80’s to low 90’s. Absolutely love the car and it is a blast to drive.

Jim

Repo Pilot

Yes Sir Jim and it seems the majority of them are like that. I don't know what is different is with the parts (If any) or the way it was assembled - clearances, etc. But it was the same with the C6-Z06's bad ones mixed in with a majority of good ones. Frankly I think it's to the point the GM doesn't give a **** anymore. Im sure - I could prevail in a lemon law action as it has been written up at least a half a dozen times, and yes it's documented - but then at this point what are they going to replace it with? A C8 ZRI when available?

17 Z06/Z07

but then at this point what are they going to replace it with? A C8 ZRI when available?

Good luck with that.............

frodoz737

FWIW...Zero issues with mine at nearly 60K miles...driving as intended. I was aware there had been previous issues and was aware of the 3X flush TSB before choosing to go A8...though I never needed it. Having said that, my first diff and trans+filter fluid exchange was at 1K miles and both are coming on 4th this month.

Repo Pilot

Luck of the draw I guess... I noticed the slippage in the cruise control the first time I took it on a long road trip shortly after "breakin" was over and I took it to the dealer for service. That's where the "paperwork trail" begins. However at that point I had yet to discovere I could show slip using the cruise control.

I knew I had a big problem where the transmission apparently overheated and the car went into Limp Mode when breaking the 200 mph barrier after a couple of miles of pedal to the floor acceleration. Strange that it never went limp on the several standing mile runs I made without much time between for cool-down, but it didn't.

Outside turner's opinion: slippage. GM's option: non-GM spark plugs. Yeah...and the dog ate my homework.

NicD

I think it's more along the line of you got unlucky seeing as how a vast majority of the 8 speed autos have no problems, and I've seen more 8 speed autos than I could count over the years. We RARELY see a problem with the 8 speed at the shop, these are probably GM's best auto trans outside of the 10 speed and I've watched the 8 speeds take damn near 1000 rwhp consistently without issue. Personally I would just spend the $350 on a new OEM torque converter and swap it in and be done with it.

Repo Pilot

Absolutely correct Nick and that's exactly what is going to happen.

The real learning moment involves one of the larger Corvette dealers in the nation who I've bought 5 cars from over the past 10 years. It was their service manage, who I've known for years, is a former C6-ZR1 owner and who apparently was having a bad hair day and choose the nuclear option and dropped a dime on me with GM.

In addition, when I asked him what and whys in the service area with at least a half of dozen other customers in ear distance along with staff that I've worked with for many years, he actually threw a hissy fit, screamed at me and blamed the transmission problem on spark-plugs, spark plug wires, and the non-GM exhaust system and then walked briskly into his office and shut the door loudly behind him. I laughed my *** off.

The next surprise was when I learned that the GM tech-rep didn't even come to the dealer to examine the car and used Covid as the excuse. It was all done over the phone. The Decoded message that GM sent to me was "we don't want to talk about it and we don't want your business" which is the same outcome that calling it in into GM Customer Support resulted in with no appeal to their decision possible. I could go on but I won't.

So what's my point??? You all be real careful out there with doing anything you may consider as just a bolt-on. Might as well raise a finger in the direction of GM headquarters and take your ZR to a tuner who understands and can work on this incredible vehicle. I'm now seriously considering the E85 mod and a cam.