skyavonee

The last 5 digits of the VIN start from scratch every year. The model year is contained elsewhere within the VIN, ensuring that no two cars have the same VIN.

GM350Z

Correct. The year is the 10th number, the engine is the 5th(usually) sometimes 8th(depending on manufacturer)

71corv

As my "VIN" falls in the middle of the list for failure I just replaced the valve springs in my 02 Z06. Used the "blue springs" from Gene Culley. As posted in this thread, the stock springs were yellow. The only odd thing was there were only 15 springs that were yellow and one spring that was what I would call gray. Don't know if this came from the factory or someone replaced one spring. When I purchased the car it had a little over 6500 miles. I'm leaning towards this being done when the car was built. Glad nothing happened while I had the car at VIR.

Gene

janky

Well you can add me to the list as of 4/19/15. 2003 Z06, springs must have failed at shutdown or startup because when I parked the car on a quick errand it was fine and when I tried to start it back up it wouldn't fire or run correctly.

2003 Z06 w/ 72,094 miles

VIN: **********110945

ZeeOhSix597

Just happened to me last night while the car was at idle. 1 exhaust spring broke.

2003 Z06 78,000 miles. Car built in 9/2002

last 6 of the VIN 107549

Ls2gtoowner

That sucks. Hopefully it didn't mess anything up. I just looked through mine and pulled a valve cover off. Mine is a late 03 and I have silver valve springs. are yours yellow? What are you gonna replace them with? Debating if I am gonna do mine

grantv

Raw with an orange stripe!? Never seen/heard of that one.
Mine are raw finish (just texted my seller, still in town for now, moving to Roatan Honduras soon; bugger), he never replaced the springs. I'm an 04Z; built 09/03 with SN 06313. Anybody go to the trouble of digging into the few 04 models that had failures, and see if they had a common build date range?

Ls2gtoowner

I am in low category but still a 2003 Z I will be replacing mine for insurance. I am not taking the chance of buying oem ones. Would rather have aftermarket ones. I called Hinson to see what they have to say. I was going to do pac 1218 however when I called them they told me they would recommend the lunati springs http://www.hinsonsupercars.com/p-1308-lunati-ls-dual-valve-spring-kit-660.aspx

I am running factory cam. My mods are ECS blower at 8psi and full exhaust. I won't be doing a cam in this motor so those seem way to aggressive. What's everyone's thoughts about what Hinson said.

ZeeOhSix597

it did a little damage, made a few dents in the piston, bent the intake valve, destroyed the exhaust valve, damaged one valve guide. Could have been way worse, I got off lucky there are many people who had their engines destroyed because of this issue.

Ive got my head at the machine shop, he is sourcing the valves for me. I will be replacing all the springs with with oem parts.

I heard the intake valves are discontinued, not so good for me.

rolexfix

On the way to work car started running really rough. Number 7 cylinder valve spring had broken. They were yellow. June 02 build. 72k miles.

skyavonee

Numbers, graphs, and lists on the first page have all been updated with the latest info.

162 broken springs and counting...

Daddie O

I have a 2002 Z06, built in November of 2001, last 5 digits of VIN are 12804. The car has 10k miles on it. Should I be concerned and look to replace the springs, or am I out of the "danger zone"?

GenerationX1

You have an early build date like I do on my 2002 C5 Z06.

My build date is 09/01 and I have 60k on my C5 Z06. I haven't changed mine as of yet but I still plan on it when I get a chance.

Daddie O

You feel you need to crack open your engine to replace the valve springs because a total of 6 people (from our build time frame) have reported failure in 13 years?

GenerationX1

Daddie O I'm not going to stress over it per say, but I will change them whenever I do a cam swap in which won't be probably until another year or so.

z06scentair

Still get a kick out of watching replies to this thread.

Qicksilverc5z

So my vin# 01448 is in the clear? Just got my 02 c5z but I think Im gonna change out the springs anyways.

Corvette Maniac

Had mine replaced this week with PAC 1218... Car has almost 100k km on it... Waiting for some pics from my mechanic how the originals looked...

The chance of one breaking is low but this gives me a little piece of mind...

Put in new spark plugs as well... 41-962 AC Delco's... Had to remove them anyway to put air in the cilinder...

acebowler1

Is it know for sure that all the original valve springs were yellow or are some another color? Thanks. I have an '02 C5Z. Build date 3/2. Vin 26083. Thanks.

MattyMaxMac

Car was running like all hell, Vibrating.
Just found driver side valve spring cracked.
Didn't drop the valve, hopeful it's straight

DD 03' Z06 54k Miles Build 05692

New Replacement from GM are stock # 12625033 - They're Blue
Replacing all 16 springs, 8 plugs(NGK TR-55) $30, 8 wires(MsD)$70
Cost around $250 in part