2017 Corvette Grand Sport blown engine
#101
I am not an engineer but you can't tell me that when they set the red line at 6500 that the true red line is not higher. I relate this to the gas gauge, when you hit empty on newer cars empty is really not empty a cushion is built in. When there is a highway off ramp listed at 30mph, one can definitely go 40mph without damage. If dipping into the supposed redline for less than a second is enough to blow this "bullet-proof" engine then this will be the last corvette I ever consider buying. I buy expensive tools with warranties that state if I drop the tool and it breaks its covered. I haven't heard back from GM yet but I know what the answer will be. Is this "high performance" car only good for traveling around the town? Sorry, this whole thing just doesn't make sense to me.
The following 2 users liked this post by Tom Letkewicz:
HooosierDaddy (06-13-2019),
MyC7BROKE (06-25-2019)
#102
Well, I am also an honest person, but learned long ago not to be stupidly honest. And this was stupidly honest. That said, those over-revs, no matter how minor, give the corporation the wiggle room to deny a claim. And true to form, the classic short-sighted American business mentality reared its ugly head and denied the claim for a couple hundred RPM over for what, a few seconds? Honda would have picked up this tab, even if you were 5,000 miles out of warranty.
The following users liked this post:
MyC7BROKE (06-25-2019)
#103
Instructor
There has to be something “more” to this story . Maybe not even known to the OP . I am quite curious at the outcome .
i am not a C7 owner yet , but this is steering me more to the Cayman.
i am not a C7 owner yet , but this is steering me more to the Cayman.
#105
Instructor
I am not an engineer but you can't tell me that when they set the red line at 6500 that the true red line is not higher. I relate this to the gas gauge, when you hit empty on newer cars empty is really not empty a cushion is built in. When there is a highway off ramp listed at 30mph, one can definitely go 40mph without damage. If dipping into the supposed redline for less than a second is enough to blow this "bullet-proof" engine then this will be the last corvette I ever consider buying. I buy expensive tools with warranties that state if I drop the tool and it breaks its covered. I haven't heard back from GM yet but I know what the answer will be. Is this "high performance" car only good for traveling around the town? Sorry, this whole thing just doesn't make sense to me.
How many times have you seen a nascar engine let go 10-100+ laps after the driver over-revved it on a restart? Or they play in car audio saying the motor is blowing up because they can feel the less power or its not making the rpms it was prior, yet they go many more laps before it actually blows up.
Last edited by born2beS12; 06-12-2019 at 10:48 AM.
#106
Some people just make some pathetic attempts to play "Big Man". I certainly don't speak for the dealer who is actually involved but I also can assure you I speak for a lot of dealers.
When you show up with the attorney, work stops! You have no right to film anything without my permission...ever! Who do you think you are to demand my communications with anybody...ever! Your obnoxious actions would assure my telling you to take your broken car and pathetic butt out of my store immediately...forever!
People who act like actual reasonable human beings get exactly what they are owed at GM dealerships 99.9% of the time. But, dealers have enough money they are not going to be intimidated by some jerk and his two bit ambulance chaser!
When you show up with the attorney, work stops! You have no right to film anything without my permission...ever! Who do you think you are to demand my communications with anybody...ever! Your obnoxious actions would assure my telling you to take your broken car and pathetic butt out of my store immediately...forever!
People who act like actual reasonable human beings get exactly what they are owed at GM dealerships 99.9% of the time. But, dealers have enough money they are not going to be intimidated by some jerk and his two bit ambulance chaser!
The following users liked this post:
MyC7BROKE (06-25-2019)
#107
Le Mans Master
I'm with you on this point. Its not like at 6499 the engine is fine and at 6501 it blows up. They would definitely build in some kind of buffer for slight temporary over-rev.
#108
Moderator
Seems like people keep forgetting about the over-rev on downshifts. No way to protect from that. The amount of damage seems to be from that situation. Amplified by the extreme speeds you can reach at the track.
#109
Instructor
Or that this was probably not a first time occurence and its just when it became apparent.
#110
Moderator
#111
Drifting
OP - TOM
JMO - I've been wrenching motors/cars and airplanes for a long time. GM: If you build a "performance engine" that can't tickle the redline now and then you built a POS motor. True performance engines are overbuilt as are airplanes because when you get close to the limits there isn't any room for error or inferior engineering and or parts. I'm pretty sure the GM engineers at the performance build center and the GM tech center built a solid motor that in testing banged the redline, over, and over many, many times. I think it would be different if the vid showed several events way-way, and I mean WAY into the 7000 range; but at 66/6700 RPM with a 6500 factory redline ?? BS this was a component failure that at sometime down the road would have showed up -- lets just say the engine was pregnant and was going to hatch at some time and not in a good way. For goodness-sakes my Acura V-6 tags the redline (6600) on the nose every-time you wind it up and I'm pretty sure Honda still has a 100K+ in mind for reliability. Tom, unfortunately honesty sometimes doesn't pay, but the real problem I see is you had a defective part in a normally well built and engineered motor, but you had a paper-pusher and a ***** for a engineer field rep that could see a clear way for a denial. I just bought a new 19 Z and I will really be cognizant about that RED LINE after how you were treated by GM. Shame on them -- "track ready" my ***!! Rant over
Best of luck getting a new motor
JMO - I've been wrenching motors/cars and airplanes for a long time. GM: If you build a "performance engine" that can't tickle the redline now and then you built a POS motor. True performance engines are overbuilt as are airplanes because when you get close to the limits there isn't any room for error or inferior engineering and or parts. I'm pretty sure the GM engineers at the performance build center and the GM tech center built a solid motor that in testing banged the redline, over, and over many, many times. I think it would be different if the vid showed several events way-way, and I mean WAY into the 7000 range; but at 66/6700 RPM with a 6500 factory redline ?? BS this was a component failure that at sometime down the road would have showed up -- lets just say the engine was pregnant and was going to hatch at some time and not in a good way. For goodness-sakes my Acura V-6 tags the redline (6600) on the nose every-time you wind it up and I'm pretty sure Honda still has a 100K+ in mind for reliability. Tom, unfortunately honesty sometimes doesn't pay, but the real problem I see is you had a defective part in a normally well built and engineered motor, but you had a paper-pusher and a ***** for a engineer field rep that could see a clear way for a denial. I just bought a new 19 Z and I will really be cognizant about that RED LINE after how you were treated by GM. Shame on them -- "track ready" my ***!! Rant over
Best of luck getting a new motor
#112
LOL you were saying? Unless the OP isn't telling us about massive over revs, the pics he did show us should not be enough to deny a warranty claim. He can probably win this in court but it will be costly and time intensive - gm knows this because they are trying to dodge their warranty obligations, just like with the GS/z06 wheels and the A8.
Now you, with your extensive experience with these matters, calls BS and knows GM is simply trying to dodge their responsibility. But, you have a lot of company chiming in. Never seen the car nor really know anything in reality but not their money so GM should certainly pay!
Now is the time though to find that attorney everyone has on retainer!
The following users liked this post:
born2beS12 (06-12-2019)
#113
OP - TOM
JMO - I've been wrenching motors/cars and airplanes for a long time. GM: If you build a "performance engine" that can't tickle the redline now and then you built a POS motor. True performance engines are overbuilt as are airplanes because when you get close to the limits there isn't any room for error or inferior engineering and or parts. I'm pretty sure the GM engineers at the performance build center and the GM tech center built a solid motor that in testing banged the redline, over, and over many, many times. I think it would be different if the vid showed several events way-way, and I mean WAY into the 7000 range; but at 66/6700 RPM with a 6500 factory redline ?? BS this was a component failure that at sometime down the road would have showed up -- lets just say the engine was pregnant and was going to hatch at some time and not in a good way. For goodness-sakes my Acura V-6 tags the redline (6600) on the nose every-time you wind it up and I'm pretty sure Honda still has a 100K+ in mind for reliability. Tom, unfortunately honesty sometimes doesn't pay, but the real problem I see is you had a defective part in a normally well built and engineered motor, but you had a paper-pusher and a ***** for a engineer field rep that could see a clear way for a denial. I just bought a new 19 Z and I will really be cognizant about that RED LINE after how you were treated by GM. Shame on them -- "track ready" my ***!! Rant over
Best of luck getting a new motor
JMO - I've been wrenching motors/cars and airplanes for a long time. GM: If you build a "performance engine" that can't tickle the redline now and then you built a POS motor. True performance engines are overbuilt as are airplanes because when you get close to the limits there isn't any room for error or inferior engineering and or parts. I'm pretty sure the GM engineers at the performance build center and the GM tech center built a solid motor that in testing banged the redline, over, and over many, many times. I think it would be different if the vid showed several events way-way, and I mean WAY into the 7000 range; but at 66/6700 RPM with a 6500 factory redline ?? BS this was a component failure that at sometime down the road would have showed up -- lets just say the engine was pregnant and was going to hatch at some time and not in a good way. For goodness-sakes my Acura V-6 tags the redline (6600) on the nose every-time you wind it up and I'm pretty sure Honda still has a 100K+ in mind for reliability. Tom, unfortunately honesty sometimes doesn't pay, but the real problem I see is you had a defective part in a normally well built and engineered motor, but you had a paper-pusher and a ***** for a engineer field rep that could see a clear way for a denial. I just bought a new 19 Z and I will really be cognizant about that RED LINE after how you were treated by GM. Shame on them -- "track ready" my ***!! Rant over
Best of luck getting a new motor
Thanks again for the post and all other folks that are supportive of my position.
#115
I asked the dealership to provide me with the ECM log. They had no idea what I was talking about but stated that this was a fair request and they would contact GM to ask about this. GM told the dealership all they needed (GM) was the VIN of the car and the engine needed to be torn down to determine fault. At this point I still do not know how they came to the conclusion that the car was over revved. No log or documentation of over revving has been provided to me yet. Still waiting.
#116
Drifting
I have hit the redline a few times and the engine backs right off. So if it is over revved is there not something wrong with the rev limiter, I am not a mechanic so I dont know
#117
Team Owner
Member Since: Aug 2007
Location: I live my life by 2 rules. 1) Never share everything you know. 2)
Posts: 136,148
Received 2,401 Likes
on
1,366 Posts
St. Jude Donor '11-'12-'13, '16-'17-'18
Once again, the rev limiter only affects throttle input (I assume it works by killing ignition to prevent over reving). Over reving due to downshifting at too high a speed/too low a gear.. well not much will protect against that
#118
Drifting
Thanks for the reply, I have only hit the redline on the way up not downshifting
The following users liked this post:
Mshindman (06-12-2019)
#119
Burning Brakes
interestingly, theres also a rev limit to the rev match function on the M7. no matter what you do, it wont peg the engine above 5200 rpm, if i remember correctly. its somewhere right around there, anyway. which suggests a certain.. conservatism, if ya ask me.
best of luck to OP. chevy seems to play very close to the vest on these things. challenge them with your logged data though, it doesnt seem like the engine went anywhere near too high. it almost seems like theyre just rendering a generic/default judgement. in this country thats called guilty until proven innocent and thats not how its done, in america. **** 'em. burden of proof is on the plaintiff BUT youve got data to back up the fact that theyre wrong...
best of luck to OP. chevy seems to play very close to the vest on these things. challenge them with your logged data though, it doesnt seem like the engine went anywhere near too high. it almost seems like theyre just rendering a generic/default judgement. in this country thats called guilty until proven innocent and thats not how its done, in america. **** 'em. burden of proof is on the plaintiff BUT youve got data to back up the fact that theyre wrong...
#120
GM powertrain specifies the maximum recommended RPM as 6600 for the LT1 and LT4. How much over this the typical LT1/LT4 can go without damage is another question as is how strictly GM wants to stick with the specified limit. If they want to play hardball, they can (and perhaps are) stating that 6,500 is marked redline on the tach giving you a 100 RPM buffer before hitting maximum recommended and you went beyond this RPM. I wouldn't care for that reasoning but I wouldn't want to try to fight it in court.
Since you have the PDR data, you can download Pi Toolbox from Cosworth and show a graph of the precise RPM for any PDR data that you have. It would be interesting to see what Pi Toolbox shows for the actual RPM compared to the peak RPM on the LCD display tach. I suspect that the ECM captures the maximum RPM the engine has seen over its lifetime and that may not have been at this track event or on this specific lap.
Here is a screen capture of Pi Toolbox. Moving the cursor across the graph will show the precise value in the data box for that point on the timeline.
Since you have the PDR data, you can download Pi Toolbox from Cosworth and show a graph of the precise RPM for any PDR data that you have. It would be interesting to see what Pi Toolbox shows for the actual RPM compared to the peak RPM on the LCD display tach. I suspect that the ECM captures the maximum RPM the engine has seen over its lifetime and that may not have been at this track event or on this specific lap.
Here is a screen capture of Pi Toolbox. Moving the cursor across the graph will show the precise value in the data box for that point on the timeline.
Last edited by NSC5; 06-12-2019 at 10:51 PM.