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FlyFisher1, sorry to read about your C7 Masterpiece going down for the count, but it was great to read that your service department had it squared away in a timely manner. I would definitely get it back to service if I smelled fuel ASAP!

SF
Rick
 

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Well, I joined the “broke motor” gang this month in my DD 2014 Z51 with 38,000 miles. Something “broke” in the motor; motor sputtered tremendously and would not idle along with violent shaking.

Chronology:
May 16 – driving home from work and stopped at a traffic light. Car started shaking violently, missing and would not idle. Running incredibly rough and shaking violently. I can only could get the motor running smooth at about 2000 RPM. Most all of the “idiot” failure lights flashing and “Service Motor” on the DIH screen. Limped the car home and put it on a wrecker to go to my dealer.

May 18 – Service technician does initial computer diagnostics with my Service Guy reporting I have a couple of “stuck valves”. He does not know if cam/lifters are affected but the technician has ordered parts to fix the issue, although the Service Guy does not have the list of parts that were ordered.

May 19 – read most of this thread and figure I am getting a new motor as a lot of others have reported. I am still under the 100k powertrain warranty, verified on https://my.chevrolet.com/home . GM has now extended the warranty to 120k miles due to the gas-tank leak issue reported on anther thread on this site. So far I have not notices any gas leakage problems.

May 21 – Service Guy says parts are ordered and the work is underway but once again does not have the list of parts nor exact cause of failure.

May 23 – Service Guy says the work will be done by the end of this week.

May 25 – I get a call today that the car is ready to pick-up and I can speak with the technician when I get to the dealership for more details. The problem is valve for cylinder #7 which is part of the AFM system. Evidently the valves associated with AFM function actually have a spring in them that activates/compresses during the AFM process so while the cam lobe raises the valve, the push rod is only slightly raised thus allowing release of compressions in the unused cylinder but not fully opening the intake/exhaust valves during AFM. In my case the valve stuck in the “partially open” position allowing fuel and exhaust to refeed into the motor’s other cylinders since the motor was not in AFM mode and fuel was being fed into #7 cylinder thus causing the missing and rough idling.

After motor disassembly, there is no real damage to the motor internals other than the valve itself. A new valve, some bolts and gaskets and the fix is done. I don’t know the overall cost of the work only that all work/parts is covered by the motor train warranty. Cost to me is $0 including getting a courtesy rental car for the duration (10 days at the dealer).

The technician stated that the AFM valve sticking issue is not limited to the LT-1 in the Corvette but all GM products that have the AFM capability. They are seeing this type of issue in all of the GM line of cars/trucks. GM is unsure of the real cause (lubrication or parts failure) but GM continues to fix the issues as they come up.

May 26 – received letter from GM noting my car “may” have a tank leak on the top of the left fuel tank fuel pump module flange which may dictate replacement/corrections. Indications are gas smell (which I occasionally have) or leaks below the tank. Back it goes to the dealer again…….
Fly fisher sorry for your ordeal. I have a manual and I never allow the car to go into 4 cylinder mode. I drive in tour or sport. But that just me. By any chance while the top end was apart did he mention anything about valve carbon/oil corking? Or the how clean or gummed up the valves where. At 38K it would be interesting to know. Thanks. Bummer you had to go back to the dealer. Hopefully the gas tank fix is done quickly for you.
 

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Not a very good weekend for Corvettes as far as I am concerned! First at the 24 Hours of Le Mans Car #64 retires with engine overheating issues! I am sorry I have been a huge Corvette fan but how appropriate the pros have engine overheating issues too! Embarrassingly my Z06s at Spring Mountain Ranch went into limp mode several times.
But this weekend my 2016 C7R with 2835 miles on it, all it once started running rougher than an old lawnmower, check engine light flashing, AND SERVICE REAR AXLE AND SERVICE STABILITRACK messages appearing at same time on info panel. I wasn’t sure I would limp 4 Miles home! That would have been impressive $125,000 car sitting on side of road. Taking in to dealer tomorrow if it can make it 4 Miles! Cavender Chevrolet failed to call me back to discuss problem. Rapidly losing interest in C8 as my Jaguar F-Type is so much nicer than a Corvette and Porsche certainly builds better quality cars
 

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If it’s an auto I had the same problem. There’s a reflash for the tranny will fix it up. I also let it sit for a day and it worked fine but with the check engine light. Either way it has to go to the dealer.
 

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Need some advice please. Short story 2014 Corvette auto with 2LT Z51 package. Got some water in the trunk area initially lost rear speakers output and outer instrument panel cluster gauges. Disconnected the battery and got the instrument panel clusters to work again. Went on to lose all speakers output....also lost infotainment display as well plus turn signals usage sound and air conditioning blowing out of seats. Checked all fuses in trunk compartment but nothing was blown. Took car to Chevy dealer who after a day said I needed a new BCM....They wanted $1350 for a new BCM plus taking off bumper to find water leak. BCM was $750 alone...so I passed on dealer repair. I found a new BCM online (exact part number) for $438...installed new BCM but no change. Any thoughts before I take it to a different Chevy dealer?
 

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There are two locations for C7 fuses. One you found below the floor in the cargo compartment. The second fuse box is in the engine compartment, right hand side, about 1’ forward of the firewall, right on top facing upward. If I remember correctly, you have two tabs in the front that get depressed, then it pivots up and out. Best of luck!
 

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Correction....my post said I needed a new BCM...but in fact it was the Bose Amp in the trunk compartment that dealer said I needed and that is what I replaced.
 

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ssscooter66, now that is a sad shot of your heartbeat, does the tech know what piece failed?

SF
Rick
 

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ssscooter66, are they replacing your engine or doing a rebuild? Seems like an awful long time to be out of service. What were you doing and how did this problem present? This should not happen under normal driving conditions. Are you getting any flak due to the engine work you had done? Covered under warranty?
 

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I had taken my Corvette to get some work done heads & throttle body, & cam . I was driving at 40 mph when this happened. It went back to the local "will known" shop & after 3 weeks of nothing being done I went & had it towed to another shop . The heads and block are damaged so no core charge.
I had to wait for the new block from Chevrolet then sent to be sleeved , then waited weeks to be bored & now waiting of the balanced crank. Just called and at least two more weeks. Dropped valve after 1500 miles after getting worked on & here's what I was told " It's literally a part failure that is out of anyone's control " . Thats odd so I guess it was just a coincidence . :mad:
Since I had the work done so no warranty. Here's a few extra pictures . Ive never seen a piston broke like that & if you can't tell the rings are holding it together !! IMG_7594.jpg IMG_7610.jpg IMG_7584.jpg IMG_7584.jpg IMG_7593.jpg
 

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Don't think I've ever seen one that blown apart. The not covered under warranty thing must really hurt. Might as well go all out now and put on a supercharger.
 

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Just bought a 2015 Stingray A8 12k miles certified pre owned.

Issues so far:

Shuddering going down the highway - torque converter replaced, flushed, and different fluid was used. This was noticed after having the car for 4 days.

PDR had black screen - Dealer couldn't figure it out so they are replacing the screen. PDR never worked and did not try it when i bought the car. Will let you know if this works.

Rattling noise at 1200-1400 RPMS at 30-40 mph. Service tech initially said this was completely normal in C7s...after looking this up online i told them to check the hydraulic tensioner and it was in fact leaking. I had to argue in order for them to replace it. It will be replaced when the screen comes in.

Last issue...the car downshifts into 1st extremely hard and goes into gear pretty rough - I suspect it is the thrust bearing/crankshaft as others have reported online. I have not had the dealership check yet because they're rude and do not seem like they want to help. I have contacted Chevy customer care for this issue.

I do not drive the car very hard and I just bought the car 3 weeks ago. I do not think I should be having all these issues since the car was supposedly inspected (172 point inspection). Anyone else having all these issues?
 

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zmayfieldwb37 Welcome to our forum. Sorry to read about the issues you are experiencing. Are you attempting to get them fixed by the dealer that sold you the CPO C7?
 

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I bought it in Charlotte NC, but the dealership here in Wilmington is trying to fix it. What year is your C7?
RedHot is a 2014 MY, picked up at NCM in October 2013.
 
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