skeet

I contacted GM customer assistance about the possibility of faulty valve springs in the 02 to 04 Z06s. I have not had a problem but I am concerned that it might be a problem according to what I hear here on the forum. I would like to know if it is a problem so I can spend, what $100 to save a $5000 engine. At first they said there was no problem they were aware of but then I reminded them that for years they were not aware of the steering column lock problem and after 3 years there is now a recall on the SCL. They said they would look into it and contact several dealers to see if there is a problem. At first they just wanted to contact my local dealer here in Prescott. I said that this dealer might see 3 Z06 Corvettes per years.
It has been 2 days and still no word from them. I will keep you posted.Sure would be helpful if someone could do a poll on having problems then I could send a copy to GM Customer Assistance, I am not sure how to do a poll.
This type of poll and communication among the thousands of members can be most powerful in matters like this. Where else can we get this type of collective information. If you had a problem please support your fellow Z06 owners.

RPO_Z06

I think your worried about something that in all likely hood will never happen to you, its like oil consumption, its such a small percentage its not worth worrying about.

skeet

That is what I am trying to find out for sure. I hope you are right.

heavymetals

It concerns me enough to change them out.

I have a CTS-V also, and I just got the Comp Cams dual spring kit.

Also, both engines in both cars are maggied.

From what I can gather, if you mod the engine (blower, cam, lifters,rockers) you are courting disaster if you don't change out the springs.

Cheap insurance on a modded motor and if it fails because of a broken spring your gonna feel even worse that you didn't do it.

RPO_Z06

The problem is this is a national board, so you might see something reported several times but keep in mind that just because you see it here doesn't mean you'll see it in real life.

This board is great but I've been here long enough to see mass hysteria for one reason or another over things that happen to like 2% of an 80 thousand car build run.

I'm on one of several C5's I've owned, and never had any springs break, and mine see red-line every time I get drive them.

If you mod your engine, then you should worry.

Relax and drive it..

slwhite

In case you did not know, dual springs are not used for reliability reasons. They are used to raise the resonant frequency of the valve train to prevent valve float. If one of the 2 springs break, it is still very likely that your engine will suffer major damage. This is because even though 1 spring may close the valve properly at low RPM, once you exceed that RPM the valve will float and ... BANG. The problem is that you cannot reliably determine if 1 spring is broken until you have major damage. If you are lucky you might hear some binding and scraping noises as the broken spring parts are moved around but I doubt it.

03QuicksilverZ06

I have an 03 z06 and after having 2 valve springs break on seperate occasions ( Luckily no dropped valve) I came to find out that G.M. discontinued the original z06 valve springs, not sure which years z06's got the new one's , although I have not yet heard about any 04's breaking springs or base c6's for that matter.

After my first valve spring broke, they replaced only the one broken spring with the new part # spring (If I had been aware of this at the time I would have demanded they change them all ), when the second spring broke they replaced all the springs with this newly designed spring (which I was also told is the same spring used in the ls2, which I also have not heard any breakages yet )

Here are the part #'s as can be seen at gmpartsdirect.com they list both, but if you proceed to checkout with the #12565313 spring it will tell you it is discontinued.

Z06 12565313 <<<< discontinued spring.

Z06 12586484 <<<< newly designed spring.

It may be helpful to you to ask GM at what time did they switch to the new springs and post it back here, it may help you and others who are worried about this issue good luck!

sapper1

Not sure if the comp dual are more reliable or not but having as set of ported heads installed and these were recommend from my tuner to go in them and he has not done me wrong yet so they will go in

heavymetals

I didn't buy the dual springs because I thought "two must be better".

Like you they were recommended and I listen to the "experts".

I only want to take the motors apart once for this stuff.

sapper1

yep once is enough

Chuck Harmon

Skeet,

While I will agree that spring breakage may be rare, my motor was ruined because the #6 intake spring broke. I had 79,900 miles, always changed oil when required (actually more often than needed) and never abused the car. It broke at idle waiting for a light to change. Punched two holes in the piston, broke the the valve end off and crammed it into the intake port. The valve stem was found twisted and hiding (wedged) in the plenum of the intake manifold.

I have driven well over a million miles in cars of numerous makes and not had this problem, or really any major motor problems before. My dad had one fail in his 2 year old 71 Cadillac that toasted his engine. Cadillac made good on it. I ended up replacing the engine on my nickel with a new 402. The new engine will be fun and I does make a few more hp than I had; but, I would rather have saved major $$$ and headed off the problem by replacing the springs last month before it broke! The LS6 is a great motor, I wasn't looking for more at the time.

Chuck

Rich Z

Well how many people having a spring break on an engine out of warranty would even let GM know about it? And how many people just side stepped the bullet by going ahead and replacing the springs before any problem cropped up? I think it would be difficult for GM to get an accurate picture of this as a problem. Is it 1 out of 1,000? 1 out of 20,000? The odds sound swell until you find that you are the one.

It might be instructive to find out why GM went to a different valve spring. They likely have that documented so this would be the info that you need to seek.

sothpaw2

This is exactly my thought-- I don't want to be that ONE. I already lost big time on my LT1--put in a new GM waterpump and Extreme duty chain set which had an excellent rep. here (Z06 valvesprings don't as this thread proves). In 15,000 mi the ED gear wore away and ruined the motor. Not likely but I was the ONE.

Then when I got it fixed, 100 mi into the new motor, an SUV hits me and totals it.

I really want a Z06 as a replacement but I just can not accept the risk of another rebuild on my coin. If I buy a Z with the effected springs I'm going to replace.

Anybody know if this is '02-'04, not '01? Are the '01 springs safe? Or maybe the less agressive cam in the '01 is not a problem for these crappy springs?

heavymetals

To summerize:

1. The valve spring was changed after 03.

2. If you mod the motor, cheap insurance.

3. Over 85k miles should be checked/replaced?

4. Two is probably no better then one (spring). If it breaks, your screwed.


Anything else?

sothpaw2

#2 is true for any motor. Any time you change lift you very well might need new valve springs as these are sensitive to lift--they can only handle what they were designed for.

#3--You can't "check" a valve spring. If the spring is going to crack because of fatigue, the crack may not even be there yet or so small you can't find it. Spring could hold the full load and still go in another 15000 mi.

#4--true for any motor. Get springs that can handle the lift and & rpm for the application.