Broken valve spring
Team Owner
Joined: Aug 2007
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St. Jude Donor '11-'12-'13, '16-'17-'18
Indeed. Since Ken is our resident zombie hunter We have to award him this patch!
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Racer
Joined: Aug 2007
Posts: 263
Likes: 2
From: Los Angeles California
So, after 7 weeks in the shop, my well regarded Chevy service guy finally found a broken valve spring as the cause of my intermittent engine misfires and CEL P0300 ( random misfires.)
I recall many internet discussions about weak/broken valve springs in Corvettes but most, if not all concerned the LS engines. Is this an issue with the LT1?
They first thought it was carbon build up and a bad injector, so they chemically cleaned the intake valves and replaced one bad injector in #2 cyl. Better but No joy!
After consulting GM engineering they did some more diagnosis and decided it was electrical problem with the ECM which they replaced under warranty. Ran good for 2 days then got even worse!
Now they started to go back over everything and they found a broken valve spring #2 cyl.
Scoped the cylinder and said it looks just fine, so they will replace the broken spring and expect all to be well.
So was the problem a weak spring that finally gave up, or something else?
Assuming the random misfires disappear, I am concerned about possible collateral damage: bent valve, damaged valve
seat ,worn / bent valve guides?
I would feel better with a compression/leakdown to determine the health of the engine, especially the #2 cyl. Am I being unreasonable?
Car has 38000 miles so only the Drivetrain warranty applies.
I recall many internet discussions about weak/broken valve springs in Corvettes but most, if not all concerned the LS engines. Is this an issue with the LT1?
They first thought it was carbon build up and a bad injector, so they chemically cleaned the intake valves and replaced one bad injector in #2 cyl. Better but No joy!
After consulting GM engineering they did some more diagnosis and decided it was electrical problem with the ECM which they replaced under warranty. Ran good for 2 days then got even worse!
Now they started to go back over everything and they found a broken valve spring #2 cyl.
Scoped the cylinder and said it looks just fine, so they will replace the broken spring and expect all to be well.
So was the problem a weak spring that finally gave up, or something else?
Assuming the random misfires disappear, I am concerned about possible collateral damage: bent valve, damaged valve
seat ,worn / bent valve guides?
I would feel better with a compression/leakdown to determine the health of the engine, especially the #2 cyl. Am I being unreasonable?
Car has 38000 miles so only the Drivetrain warranty applies.
Team Owner
Joined: Jun 2005
Posts: 46,295
Likes: 2,596
From: Northern, VA
St. Jude Donor '15
"In honor of jpee"
yeh, I do.^^^ how many miles on the car---have you owned it since new?
but still, for a '16 to start doing it like that, I'd say it's time for more than "just" one valve spring replacement.
what is the collective opinion of CF members?
but still, for a '16 to start doing it like that, I'd say it's time for more than "just" one valve spring replacement.
what is the collective opinion of CF members?
Team Owner
Joined: Sep 2000
Posts: 25,002
Likes: 2,704
From: Far NW 'burbs of Chicago
St. Jude Donor '13
Hopefully, you can persuade the dealer/GM to replace all the springs at once.
You might point out that if you keep it up, sooner or later they'll have to give you a whole new engine if you're in warranty when the current one self-destructs.
If they won't pay for all new springs, you might consider paying for the other springs while they have it apart to fix the latest one.
If not under warranty, I'd definitely pay for all new ones.
I can't think of any reason for all your spring problems other than a defective batch, does anyone know of other possible causes?
Le Mans Master
Joined: Oct 2014
Posts: 8,672
Likes: 2,726
From: Atlanta GA
I agree they should replace them all , I to had a valve spring break but I was not so lucky as I was going 70 mph down the highway by the time I got the car stopped the valve fell into the cylinder and you can imagine the resulting CARNAGE ... they replaced the motor
But if they were able to fix my motor I would have demanded they replace them all
Dave
But if they were able to fix my motor I would have demanded they replace them all
Dave
Pro
Joined: Oct 2014
Posts: 742
Likes: 54
From: Yonkers New York
2015 Z06 - 68,000 miles - mostly backroads with fair amount of engine braking but not excessive throttle use/abuse at all....spirited & enthusiastic, at best
2 valves springs 1 @ 35k the other @ 55k
3 flex plates
1 Torque Converter
1 Rear Differential - the whole "pumpkin"
3 Rims - dented cracked molested
5 sets of Cup-2’s
Can’t wait for the C8 Z06 !!
2 valves springs 1 @ 35k the other @ 55k
3 flex plates
1 Torque Converter
1 Rear Differential - the whole "pumpkin"
3 Rims - dented cracked molested
5 sets of Cup-2’s
Can’t wait for the C8 Z06 !!
Last edited by Rd16rr; Oct 31, 2019 at 07:10 PM.
Administrator
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Sure hope my 2014 does not experience any broken valve springs. Do not need that hassle.
