That might also help determine which cars are affected. I have an early '02 (delivered in Sep '01) and reading these threads makes me pretty nervous - people just say, "I have an '02," and not when it was made or delivered or anything to help narrow the field. It's likely a bad batch of springs.

 

If this will help you piece things together regarding a defective batch, my '02 Z car was delivered November 30, 2001. If there is a trend I would probably try to get some compensation from GM.

Chuck

 

I've had 2 broken springs in my early 03 z06, first breakage at 14637K the second at 19433K this is NOT a bad batch, but a bad design, My first break was just lightly releasing the clutch, my second the clutch was fully engaged.

I have done a lot of research on this and the late 03's got the newly revised (now ls2 springs) I've yet to see an 04 or ls2 with a broken spring at low load..

Don't know exactly what part of 03 they changed but the part numbers are:

Discontinued Valve springs part # 12565313
Replacement Valve springs part # 12586484

It made me feel better when I saw this replacement valve spring used at Lingenfelter performance part# 12586484

Lingenfelter Performance recommends and uses the factory LS6 valve spring with our GT2-3 camshafts. This valve spring is good for camshafts up to .580” lift. These valve springs can also be used with stock camshafts as a replacement for worn out stock springs. These are a direct drop in spring that will not require any machining and use the stock retainers and locks. Sold in sets of 16

Some advice to people with the old springs in, if you get a hard shuddering of your vehicle at low load, shut her down immediately and DO NOT try to start her again for anything, one guy dropped a valve and blew his engine trying to restart for the towtruck If it happens at high load well

Sorry for being long winded, but it is cheap insurance to switch these out , just think of the potential outcome http://www.muchneeded.com/galleries/...page_0001.html Good luck..

 

hey Cobra4B,

Oddly enough I've never heard of a 01 break a spring yet, I wonder if the slightly bigger cam in the 02's were just enough to push these springs to the breaking point, but if i were you i'd go for the springs and cam anyways

 

There does not seem like a lot of Z06 owners are having this problem. If i am not wrong there have been no more than 5 or 6 members with this problem.

 

This seems right. There are thousands of zO6s around, so the probability of a failure on a given car is pretty low. You have to weigh this before spending money on preemptive replacement springs and other hardware. Guess I'll take my chances.

I do feel bad for the guys who are afflicted with this. I'm assuming that although many failures seem to occur at low engine load, the engines experience high stress at other times (tracking, dragging, etc.). Is this right, or are these cars truly pampered?

 

Who buys a Z06 and doesn't drive it... honestly...

I can't say mine is pampered. I can say that I maintain it properly - and that included having the valve-springs replaced at 75k miles, just in case.

 

From your research, when in the '03 MY did they change the springs to the new part #? And do the '01's have the old part #? As you have said I have not heard of '04 or '01's having the problem, I assume because the '01 have a smaller cam.

 

This has also happened to a few CTS-V owners.

The CTS-V came out in 04.

In 06 they are using the LS2.

 

Sothpaw2

I wish I knew what part of 03 they discontinued the original spring, I assumed the same about the 01's and the smaller cam not stressing the springs as much as the more robust cam. Here is one of the E-mails I got when I was asking for information regarding spring breakage.

You broke a spring and thats all??? Twice? Did the engine just stall out
>> on you before it had a chance to damage itself? I had a weak valve spring
>> in my '02 which I could hear for a month or so. It broke as I was
>> restarting the car after it stalled. It blew pieces all over the engine.
>> The valve stem got pushed out the exaust and stuck in the Cat. the rest of
>> the valve spring and pieces pushed a hole in the oil pan. Chev. replaced
>> the entire engine under warranty. I went to Crane roller rockers after
>> that, mainly since the car is solely a track car and I need the
>> reliability. the same time I had my incident there were at least two other
>> guys here that had springs go south with major engine damage...on '02's
>> that is...I think it was more than a bad batch of springs...It was more
>> likely poor design, but I'm sure I would get an argument from some here on
>> that point. Hope you're on the road soon!
>> Steve

Maybe this thread will help others that if their car starts to shudder at low load, Shut her down and "Do Not" restart the car under any circumstances, I even instructed the mechanics not to try to start it

 

I hated hearing these stories about broken valve springs on stock LS6 motor and with my stock LS6 motor in my Z06 pushing over 550rwhp with my ATI D1SC ECS Blower Kit, i finally swapped out to 918 springs and chromoly pushrods about 1000 miles ago and have much better piece of mind at this point in time! It seems that if you have over 50K miles on your stock Z06 motor and you drive it hard, you should probably make this type of replacement for valve spring maintenance and added insurance!

 

well, stumbled upon this thread and realized others have had valve spring problems


I was driving at 25-30mph, on my way to the dealership to get pads/rotors changed for a DE and I heard a 'flapping' sound-I started to pull over and then smelled something burning and the vette went dead.

Barely got it on the tow truck, didn't want to start it back up again.

Dealer called me yesterday-valve spring went out.

65K miles on the Z06.

I am going to replace the entire set-any suggestions on if I should go with an aftermarket replacement, or a newer year Z06 spring set?

 

From the information I could gather, valve spring replacement is a "must do" on a modified motor.
I have a set of Comp Cams duals in my CTS-V.

Have another set waiting to be put into Mr Vette.