In my case, dealer found a brkn valve spring while investigating a random misfire at 30,000 miles. Replaced the bad valve spring under warranty.
Then, at 62700 miles, broke another valve spring on the highway at 55 mph in 6th gear. This one dropped into the cylinder and cost me a new engine that was no longer under warranty.

How did that old TV commercial go?
"You can pay me now or pay me later"?

Change them all!

 

How common is this on the LT1 motors? I have a 2017 GS

 

It happened to me last year. 2014 Z51 manual with 53k miles while on the highway 8 hours from home. I drove it that way for several miles until the next exit.. I had just filled up so thought it was bad gas or something. Luckily the valve didn’t drop and it happened near a small GM dealership. It was $550 and a few days to fix the one spring.. which was like a $8 part. After I got it home I replaced all the springs (got blue striped ones), valve seats, and upgraded/replaced the rocket arm trunnions. Very inexpensive to do if you do it yourself. I got lucky the first time and dodged a 14k out of warranty bullet. Been running great since. First owner tracked the car a bit so perhaps that was a factor 🤷‍♂️

 

Sorry that happened to you Sir. My car is somewhere around 26k and i just bought an extended warranty 4 months ago. Will be replacing ALL of the valve springs!

 

It happened to some friends while on a road trip. They had their C7 towed to the nearest Chevy dealer, who called them back after a few days and told them they had a thrown rod and the motor would have to be replaced at a cost to them of $17,000.

Further discussion with the service department revealed the techs had run the motor up to high rpms in checking it and that's when the rod went through the block. They acknowledged they never checked the oil pan or the rocker arms.

Chevy intervened and covered most of the cost of the motor replacement.

 

GS has about 34k now.This is the reason I stay under 6k rpm's.Got till June on the DTW.My luck I weaken them with various 6k spurts just to weaken them to break after the warranty.Approaching 6k on the street is pretty darn good performance.
These engines love that 3k to 4500 range of acceleration after looking at dyno sheets here over the years this engine loses pulling power.
Unless you help it leaving warranty.
I believe your Corvette keeps a accurate history of how much you rev or over rev these things to hurt a possible claim?I could be wrong but why wouldn't GM do that?

 

How can you over rev your engine with the rev limiter? if it is unsafe to run the Lt1 up to redline why would GM not reduce the redline? Just curious.

 

What is the redline number.Think I hit once maybe twice?It just goes into a flat spot if I can recall.I believe your computer keeps track?Correct me if wrong.
I don't have to finances to push it.Stay in that rev limiter often I would think increases the odds a bit of breakage.My opinion just thinking..

 

You really are over thinking this 😬
The car does not log events like how many times have you run it up to rev limter ... also like said above you have to work pretty hard to over rev a motor that has a rev limiter

Dave

 

Are you sure? What keeps track of a tune?Different parameters changed right?

 

it's pretty easy with a manual if you miss a shift say going for 3rd and get 1st instead. Kablamo!

 

A small file called the CVN file , it counts how many times the ecm was updated agaist what GM says it was updated because all updates run thru GMs TIS website ( old name i forget what the new name is ) . If the CVN count does not match GM's count ...
Now you are taking a file that might be a couple of KB at best against a log file recorded every time you redline the motor

The car was made to race and GM set the redline and to keep idiots like me from over reving the motor they gave us a rev limiter Now you think they are going to void your warranty because you raced the car lol lol

When my valve spring broke my PDR had about 2 hours of 1/4 mile trips recordings on it , after the motor was replaced the service manager even joked and said , let it break in before you take it to the track so i know they all watched my 11 second runs down the track .....

Dave

 

The thing about a Corvette engine is, unlike truck engines and regular cars, every part in the engine is intended to offer an edge of performance, quite pushed to the limit given the displacement available, and often stripped of 'unnecessary weight' which may further weaken parts under various circumstances.

This results in added stress on almost all parts no matter how you drive even just at idle can be a significant stress on valvetrain hardware.

Also part of added stress is how the vehicle is operated. People seem more likely to redline a Vette engine on a daily bases than a truck or corolla.

Honestly, personally, I would never reinstall a 'vette' engine into a Corvette once its done. I would rather use a modern Aluminum (light weight) truck engine which can support 1000 horsepower such as the L33, far more reliable than a Corvette engine and much lower cost.
It would not have the punchy torque of large displacement but it would have double the power and an exponential reliability.

<flamesuit active>
Its not as crazy as it sounds
https://www.corvetteforum.com/forums...post1595514431

Its not unheard of, although
Don't make the mistake of machine work. Just use the stock engine for reliability.
https://www.corvetteforum.com/forums...post1591603291

I mean, stock bottom end = SBE = 1000 horsepower capable
https://www.corvetteforum.com/forums...ase-build.html

So those engines cost less than 2k and handle 1000hp. I can set one up to live for 150,000 miles like that, pretty easy if you know what you are doing. But people still spend 10k 20k on an engine with half the power... kind of crazy to me? All this talk and worry about valvetrain issues.... I recommend use a low lift valvetrain and have 1000hp rather than the high lift stressed out setup making half of that.

My goal/motivation is to increase awareness and save people money... I have nothing to sell or gain from any of this. I understand some people just want NA power and/or large displacement. But for those who simply crazy power, reliability, and affordability... It isn't in the Corvette engine or any derivation of such

 

This is NOT a common occurrence, as someone else mentioned above. Also, you're kidding yourself if you believe this is an automatic transmission only problem. Happened to my 16 Z51 M7 at 7,200 miles. No matter on highway or parking lot, you run the risk of scoring the cam. Make sure your tech checks it carefully. Mine was at low speed, but it scored the cam. Under warranty, my tech replaced literally everything from cam up, including the vlom.

 

Any particular year or is it totally random across the C7 run beginning to end? Mileage seems also random; from almost new to high mileage 70,000 cars.

Moderate tracking the car does not seem to correlate, according to the posts.

I have a base '16 LT2 that has seen light track time, but is otherwise normally driven with 17,000 miles & regular maintenance.

 

Brkn springs seem totally random among both street driven and occasionally tracked C7's like mine. As others have said, this is NOT a common occurrence. Although the problem seems to persist into the C8 program as well, based on internet posts I've seen.

I will be looking at aftermarket springs to replace mine when the 3 year warranty on my crate engine expires.
Any specific replacement parts recommendations appreciated.

 

I have never tracked mine, mostly drive in Tour mode, on occasion spirited driving but mostly just cruise. No mods other than x-pipe and GM CAI. Also use the recommended AFM range disabler. Car is a 2015 Z51 with A8, a little bit over 26k miles.

 

I’d call lingenfelter for a recommendation I did for my C6 and wound up with a set of matched stock springs

 

My warranty runs out in a few weeks. Anyone have an approximate cost parts/labor to replace original springs with with the best springs?
What brand is recommended for a Z51?