When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Got my valve covers opened up today and was relieved to not see yellow valve springs. They’re all grayish with no visible stripes. Not knowing if they’ve ever been replaced, I’m going to go ahead and replace them.
VIN 135223
6/18/03 build date (next to last day of ‘03 production)
stock, 13,900 miles
Last edited by slapshot12; 10-02-2020 at 05:21 PM.
'03 Z06, 11603 last 5 VIN. Had a spring snap LITERALLY less than 30min after I took possession of the car (last fall) at around 86k miles. Prior owner picked me up in vette, we drove to his house, filled out paperwork and exchanged monies, I drove to get fuel and it started showing miss/low power and even backfire type behavior driving home from gas station (normal street driving, no high RPM, etc)....making me think 'bad gas' (because I'm dumb). Basically, if I'd waited almost any time at all before pulling the trigger, the prior owner would have been on the hook for the fix instead of me. <Le Sigh>
Not that I knew about this issue when I took possession of the car, but even if I HAD known, I would have had no opportunity to take care of it before it 'took care' of itself.
Dead center spring is the broken one...if you can't see the metal shear at the base.
Last edited by Josairus; 10-13-2020 at 10:06 AM.
Reason: Picture add
'03 Z06, 11603 last 5 VIN. Had a spring snap LITERALLY less than 30min after I took possession of the car (last fall) at around 86k miles. Prior owner picked me up in vette, we drove to his house, filled out paperwork and exchanged monies, I drove to get fuel and it started showing miss/low power and even backfire type behavior driving home from gas station (normal street driving, no high RPM, etc)....making me think 'bad gas' (because I'm dumb). Basically, if I'd waited almost any time at all before pulling the trigger, the prior owner would have been on the hook for the fix instead of me. <Le Sigh>
Not that I knew about this issue when I took possession of the car, but even if I HAD known, I would have had no opportunity to take care of it before it 'took care' of itself.
Dead center spring is the broken one...if you can't see the metal shear at the base.
I've read that "pre-mature" valve spring failures manifest at low miles. Your car has 86K, so I don't know if what I've been told is correct. Either way, you got the short end of the stick. I traded my 2002 Z06 with 17K for a 2015 Z06 with 15K last January, so I won't have to worry about the valve spring thing any more.
Bought an '03 Z06 this year and because of this forum I decided to change the valve springs. 39k miles, one owner, stock.
Springs replaced locally by experienced Corvette guy, 11/20. Car had a late June 2003 build date. The original springs were silver-grey
not yellow and none were cracked or deformed. Replaced with OEM LS-6 springs, also silver grey color. One less
thing to be concerned about, glad I saw this forum. Found out I needed plug wires so I am glad I did it. Love the car, total gem.
One of our members here, Bud Miller, just had a valve spring failure in his 2004 Z06, this week. Bud was just driving down the highway, at 75mph.
Car had 75k miles and was completely stock.
I want to give a big thank you to the forum for all this Data. I was lucky enough to find a low mileage 03Z and thanks to you guys and this thread the car is at ECS as we speak getting the springs replaced with manleys. since its there decided to have them slap in a corsa extreme and performance tune. since I bought it it has been not neglected but not taken care of as it should. luckily it sat in a garage and just needed the right owner. I have found a lot of joy bringing it back to life bit by bit and scanning the forum for advice and dos and donts. Thank you guys, can't wait to get it back and get some spring time weather.
Car was stock at purchase and has 19,200 miles. No issues but after this never even wanted to risk it.
Last edited by DadbodBolt-Ons; 03-01-2021 at 06:18 PM.
Glad I came across this thread about the valve spring issue. After reading about it, I decided to get mine replaced. Had it done on 07/14/21 by an experienced tech that I know who races C5s and builds LS motors. My '02 Z06 was built on 01/25/02 (last 6 of VIN are 119876) and has 34K miles on it. It did have the yellow valve springs in it. We replaced those with the new updated springs. Just as an FYI, the new part number is 12713265. The box had 19420455 on it but the individual springs were each labeled with 12713265 PN. I verified they were correct with GM Performance Parts and Summit Racing. Looks like the previous blue springs (12499224) have been discontinued.
For those who are thinking of doing this on your own, just be sure you have all the right tools. I got to watch as the tech was doing the work and have to say it was a lot more involved then most on here mention. If you're comfortable and experienced with engine work then probably not a problem, but if you're doing it for the first time, then just be sure to do your homework before tackling this.
Really glad to have that done now for peace of mind. Thanks to all the forum members who have contributed to this thread. Great to be able to share things like this!
My '01 had the spring fail on (IIRC) cylinder # 4 right around 80k miles. Was driving home from work, 6th gear, around 80mph or so and it just gave out. Car at the time was pretty much stock aside from a Halltech Intake, B&B Quad Exhaust, and custom tune. Luckily no issues other than the spring failing and I was good to go. Car is now at about 96k.
My '01 had the spring fail on (IIRC) cylinder # 4 right around 80k miles. Was driving home from work, 6th gear, around 80mph or so and it just gave out. Car at the time was pretty much stock aside from a Halltech Intake, B&B Quad Exhaust, and custom tune. Luckily no issues other than the spring failing and I was good to go. Car is now at about 96k.
What color were your valve springs? Yellow? Glad it didn't do any real catastrophic damage to your engine.
What did you experience when it happened? Just curious.
What color were your valve springs? Yellow? Glad it didn't do any real catastrophic damage to your engine.
What did you experience when it happened? Just curious.
I believe they were the yellows. For some reason something's making me think they weren't though. I have photos somewhere that I gotta look up, I took them when I pulled the valve cover off the next day to check out the damage.
When it happened I was cruising along as I mentioned in the previous post, and then suddenly the car went really quiet but I didn't realize it(low RPM cruising speed) I guess from the road noise and stereo drowning it out. I turned down the stereo and noticed the RPM was at 0, so I popped the clutch and it turned back on, but the exhaust was really low/deep sounding, moreso than usual. Obviously could tell something was wrong. My dumbass actually drove it home off the freeway, keeping the RPM up with the gas pedal for about another 3 or 4 minutes total(the off ramp and street go over a small freeway overpass bridge which really fucked me being able to stop safely) before I parked at a gas station and got it towed the rest of the way home. Was like 3 minute drive from home but didn't want to keep running it more than I already had.
I believe they were the yellows. For some reason something's making me think they weren't though. I have photos somewhere that I gotta look up, I took them when I pulled the valve cover off the next day to check out the damage.
When it happened I was cruising along as I mentioned in the previous post, and then suddenly the car went really quiet but I didn't realize it(low RPM cruising speed) I guess from the road noise and stereo drowning it out. I turned down the stereo and noticed the RPM was at 0, so I popped the clutch and it turned back on, but the exhaust was really low/deep sounding, moreso than usual. Obviously could tell something was wrong. My dumbass actually drove it home off the freeway, keeping the RPM up with the gas pedal for about another 3 or 4 minutes total(the off ramp and street go over a small freeway overpass bridge which really fucked me being able to stop safely) before I parked at a gas station and got it towed the rest of the way home. Was like 3 minute drive from home but didn't want to keep running it more than I already had.
Glad the valve spring breaking didn't grenade your motor. I'm assuming your changed out all the springs after that. You were fortunate compared to others who experienced that. Really glad I replaced mine so I have peace of mind now when driving it. Those yellow springs I'm sure were a ticking time-bomb.
Glad the valve spring breaking didn't grenade your motor. I'm assuming your changed out all the springs after that. You were fortunate compared to others who experienced that. Really glad I replaced mine so I have peace of mind now when driving it. Those yellow springs I'm sure were a ticking time-bomb.
You know what, now that I thought it over pretty well, I'm almost positive they were blue valve springs. Not yellows. But yea, I was expecting the worst when it happened. Did a compression test and other stuff immediately the next day(took a personal day off work to get the time to figure it out asap since it's my daily). Was so relieved after checking it out.
You know what, now that I thought it over pretty well, I'm almost positive they were blue valve springs. Not yellows. But yea, I was expecting the worst when it happened. Did a compression test and other stuff immediately the next day(took a personal day off work to get the time to figure it out asap since it's my daily). Was so relieved after checking it out.
Hmmm, that's interesting because the "blue" valve springs are what were recommended to replace the "yellow" ones with. Wonder if your valve springs were replaced before your incident.
Hmmm, that's interesting because the "blue" valve springs are what were recommended to replace the "yellow" ones with. Wonder if your valve springs were replaced before your incident.
Yea, not sure myself. A few fbodies ago I remember looking at which springs were which, and I remember being under the impression that 01 LS6 motors were not yellow springs, and that 02-04 LS6 came with yellows from the factory to correct defective springs. A quick google says 01's came with light blue springs, and that yellow were the 02-04 springs.
10-01-2020, 11:36 AM
