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Was driving yesterday when unfortunately my 14 Z51 A6 with 34,000 miles started to shake and lose power. Ended up having to put it on a flatbed to take it home. Car is out of warranty and decided to do the diagnosing myself. After checking the forums for the symptoms my car had, it boiled down to either being lose spark plug wires, bad gas, or broken valve spring. Well after checking everything else i pulled the valve covers off and sure enough a broken valve spring.
Also after i brought it home i noticed the doors did not want to open and it seemed the car lost electrical power. Checked the battery and it was the factory battery from 2014 so i went and got a new one. Weird how it died after the spring broke.
I am 23 years old so i definitely do some "spirited" driving i also hit the drag strip every couple of months. I take very good care of the car otherwise. Not sure if this is completely my fault or part to blame on GM.
I am in no way experienced with these kind of failures my main concern is the valve dropping and hitting the piston. Can a spring break and no other damage be done? The spring is broken but doesn't look like it dropped too far?
Of course the best way to tell is look at the piston through the spark plug hole which i will try tomorrow. Hoping its just the spring so i can replace them all with new springs and be done with it.
Any general advice or input would be appreciated regarding these types of failures and the repair process. The car is Bone Stock. Spring in middle is broken
You can get lucky and brake a valve spring and have the valve stay up as it appears in your case. If it interfered you’d have some damage which includes at least a bent valve. Change the one spring and you can do a leak down test and see if that cylinder seals. If it does then you’re in good shape. I’d move on to changing the rest of the springs then to be safe. You can also change the one and run it but the leak down will tell you for sure. It’s not a tough operation. Also, there should be plenty of how to’s here but any questions just post up and people here can answer.
You can get lucky and brake a valve spring and have the valve stay up as it appears in your case. If it interfered you’d have some damage which includes at least a bent valve. Change the one spring and you can do a leak down test and see if that cylinder seals. If it does then you’re in good shape. I’d move on to changing the rest of the springs then to be safe. You can also change the one and run it but the leak down will tell you for sure. It’s not a tough operation. Also, there should be plenty of how to’s here but any questions just post up and people here can answer.
Since you took the time to pull the valve cover off and find the broken spring, seems to me like you are a candidate for fixing this yourself. See my thread on essentially the exact same issue: https://www.corvetteforum.com/forums...rear-axle.html
While I certainly cannot guarantee it, your valve spring broke much in the same manner as mine, and as best I can tell, there was no other damage to my engine. So, realistically, it's going to cost you one new valve spring ($4 + shipping) plus some tools if you don't have them already. I would suggest you do what I did, and at a minimum, replace all the springs. Trouble is, Chevy is having a hard time with a current batch of the same springs in the C8 (the blue ones, that's what you want, to replace the yellow-stripe ones you have), and so you might have a wait in terms of getting a new spring.
TL, DR: You may have been reasonably lucky and all you need to do is replace that spring. It'll take you an afternoon once you have the parts and tools ready.
Also, where are you located? I have little use for my old (yellow-stripe) springs (I only have 15 good ones, after all :-) ), so you are welcome to one if you can't get replacements right now ...
If you get lucky with just the broken valve spring. Don't just replace the broken spring, replace them all as AEK suggests.
I had a brkn valve spring on my '16 Z51 at 36000 mile and had it replaced under warranty. Just the broken spring. At 61700 mile I had another brkn valve spring and this time the valve dropped into the cylinder. And now out of warranty! New GM crate motor is $14K. Change all the springs. I'll be changing mine every 3 years or 36000 miles on this new motor
I will be going to a couple dealerships today to see if they have the springs in stock. Definitely going to be replacing all of them. I got another close up picture of the broken spring looks like i may have gotten lucky. I will do a compression test before i replace them to be safe.
Also, where are you located? I have little use for my old (yellow-stripe) springs (I only have 15 good ones, after all :-) ), so you are welcome to one if you can't get replacements right now ...
I am located near Dallas, Tx. Going to some dealers today to see if they have any in stock or how long they will take to order.
Car has been fixed! Had a broken valve spring as well as a bent pushrod. There were a couple of other springs that looked like they were on their way out as well.
Got super lucky the valve didn't drop. Will post some pics below. Back Home!
Had this issue with my car in '17, but the valve dropped and took the motor with it. I don't remember which springs the "blue" ones are, but I hope for your sake they're dual or the newest improved design.
Interestingly enough, I got a TSP long block with custom heads/cam and ported intake/tb installed and tuned for less than a GM crate LT1.
10-04-2020, 02:42 AM
14 Z51 Broken Valve Spring Questions
Had a broken valve spring as well as a bent pushrod. There were a couple of other springs that looked like they were on their way out as well. 
