C7SHARK FL

So last night my c7 broke down in the middle of the highway. Car was running normal, I was just cruising at about 60 mph. All of a sudden the car begins shaking like a thing possessed. My first reaction was that the engine sounded like it was misfiring. I pulled over, put the car into park, and the car was still shaking. (Felt like a stampede of cattle was going past me). I turned the car off and the shaking stopped. I tried to turn the car back on, it lagged and lagged and didn't turn on. I attempted to do it again and the car started, but choked something fierce, and then continued to shake. The engine made horrible noises and it didn't sound like everything was firing correctly. The error code on the center cluster display was "Service Rear Axle". I am not sure what that has to do with anything.


I ended up having the car flat bedded to the dealership for service. It is still under warranty. Has anyone else had this issue? Anyone have any idea what it might be?

**I will update this thread as I obtain new information.**

davepl

That's a new one as far as I know, but I'm sure we're all curious to find out what it was, so please do post once you get a diagnosis!

C7SHARK FL

Will do. Dealer says they should be able to look at it later today or tomorrow.

NSC5

Service rear axle will show up whenever there is an engine problem because the control systems for it won't work properly when the engine isn't operating normally. The same is true for the traction control and stability systems which both depend upon predictable engine power delivery for proper operation.

It could be a number of issues (ignition or plug, valve spring, or an issue with the fuel system (either low or high pressure pump)). Since this isn't an intermittent issue it should be easy for your dealer to locate the cause and as long as it is stock warranty will take care of you.

mike96ss

100% Correct. Same thing happened to my 2015 last year. I was only going about 25mph. I was also lucky I was less than a mile from home. #5 Exhaust Valve Spring broke. Got lucky it didn't drop the valve. Dealer replaced it and all is well.

C7SHARK FL

So update #1:

Dealer read the codes on my car. Got a MAP sensor code. So has something to do with my air intake or potentially throttle body?

Any ideas. Still inexperienced in these matters.

Corvalex

Could be a typical code for a broken valve spring.
A valve stays open, Air is pumping in your intake manifold, and the manifold-pressure increases over normal level.

iclick

What YM are these two cars?

C7SHARK FL

Mine is a 2016.

Mike's I believe is a 2015.

blue_bomber697

Mine displayed the exact same symptoms when it dropped a valve and destroyed my motor. Hopefully that is not the case for you.

boostaholic786

sounds like a valve spring or something in the valve terrain...Sorry to hear that and havent heard of that many C7's dropping valves like the LS7 did....hmm...

NSC5

Here is the bulletin for the valve spring issue: http://www.corvetteactioncenter.com/...0506-1315.html

C7SHARK FL

**FINAL UPDATE**

Sorry it took so long for me to update this, I wanted to resolve all issues on my end before I got to the forums for discussion.

As it turns out, my entire cylinder went. Apparently the lifter dropped, which somehow messed with the pushrods. Those bent and pushed the spring out of place, which shattered and went out my exhaust? The piston fell sideways, the top snapped off into my intake port? However, there "was no damage to the cylinder wall". I believe the tech because he is a good guy, we've had a good relationship since my father's c5, but I don't see how i suffered no damage... Dealership checked the surrounding engine parts, and decided a full engine replacement was not necessary. They simply replaced all the above mentioned parts and replaced the headers. Still not sure how all this happened, I am not particularly rough on the car.

Since then I have traded the '16 stingray in and purchased a '17 Grand Sport. I am loving the widebody look and the enhanced handling. The confidence it inspires is incredible. I loved the stingray, I just didn't have faith that if something wasn't working right in one part of the engine that other parts of the engine weren't getting damages while compensating.

Hopefully this one can keep it together.

robert miller

^^ glad you got her fixed & also more got a new GS also.

rrsperry

Ok... how does an exhaust spring go out the exhaust?

The piston went sideways?

I get it, you're not a mechanic, but damnnnn. That sounds like gibberish.

Hope they fix your engine. (I'd be wanting a replacement if you actually broke a piston....)

C7SHARK FL

Just repeating what they told me. I don't understand any of it. I am an attorney by trade. They could have told me that the flux capacitor was acting up and they had to hit it with mjolnir to fix it and I would've nodded and smiled. I think someone was selling me a bridge on this issue, but suffice to say all the components in one of the cylinder needed to be replaced.

brettmess24

How do piston, push rod or anything else get by the valves into the exhaust with no damage? Impossible!!!!

C7SHARK FL

That is what I want to know. And how does it not annihilate the cylinder wall? AND why did the oil pressure suddenly get peaky? Just too many worries, that is why I traded her in.

blue_bomber697

This sounds like what happened to my car.. I dropped a valve in cylinder 7. Destroyed the cylinder wall and everything else that it sounds like happened to you.

My cylinder wall was very wrecked so I'd be surprised that yours was undamaged.

Unfortunately for me, they wouldn't touch my car on warranty cause of my supercharger and I had to pay a hefty price to get everything fixed up. Glad you got yours replaced and then traded the car.

RickHoppe

I can't understand how that much damage could not detroy the entire engine. I hope you bought your new car at a different dealer.