[Venomcustom]

Originally Posted by FH212

I have around 300 miles now. I am going to go for a few rides this weekend and get some more miles and see how it goes.

Good plan. How do you like the A10 vs the M6? I was torn.

[FH212]

Originally Posted by Venomcustom

Good plan. How do you like the A10 vs the M6? I was torn.

I am getting used to it. I still get in and my foot goes for the clutch lol. So far I like it. But the true test will be when It's broken in and I can actually get on it to see how it is. I do like the shifting it holds in Sport & Track. All 3 modes you can feel the difference in shift points.

[arpad_m]

Originally Posted by gtfoxy

They run-up dyno every engine?

Yes, they put every single engine on a test bench that measures 1500+ parameters during a dry (compressed air) run, see below.

The pictures are from the LGX assembly line, but the process is likely very similar for the LT1 and the LT4.

[Venomcustom]

Originally Posted by FH212

I am getting used to it. I still get in and my foot goes for the clutch lol. So far I like it. But the true test will be when It's broken in and I can actually get on it to see how it is. I do like the shifting it holds in Sport & Track. All 3 modes you can feel the difference in shift points.

Awesome!! Looking forward to hearing how it is when you start really getting on it.

[Thill444]

Originally Posted by Petrol Head

The point is to prevent complete engine destruction to begin with. If a valve spring breaks that’s easily $20,000 GM is shelling out in parts and labor vs maybe $3,000 for new valves and the labor to the dealer for it. Not to mention no one wants a new car with a motor that has to be torn down to the block and rebuilt.

Not the way it works, unless it is a safety recall. We have had one report of a single Camaro with valve spring issues and maybe a dozen C8's. Remember this is not just a Corvette or Camaro issue it's across the following engines:
L87, LT1, LT2, LT4,L82, L84, and L8T

I have no idea how many vehicles we are talking here but to replace valve springs across all of them when maybe less than 100 or 1000 vehicles are actually affected is the math GM has likely already done.

Also not all valve spring failures result in a catastrophic failure. A number of people got an engine light and were able to shut the car off and get it in for service before a significant failure.

Now if this ends up being more widespread and you have safety issues or lawsuits it can change to a recall situation.

I am one of the people affected so I have every reason for GM to replace everyone's valve springs but I am also a realist and know how these things work. I have owned numerous Subaru STI's and WRX's over the years and everyone knew for multiple generations about piston and oil starvation issues with the EJ engine and it took many lawsuits for Subaru to admit fault. So the flip side of this is that GM could have not announced the TSB and then just swept failures under the rug by quietly fixing them.

[GearheadSS]

Originally Posted by FH212

Is there a certain mileage that they seem to fail at? Just wondering if there is a point that if it hasn't gone by this xxxx mileage your probably fine.?

The highest mileage I've seen reported is around 700. Most that make it above 500 seem to be fine. The majority that I've seen with a failure happened within 200 miles.

[GearheadSS]

Originally Posted by ember1205

Since GM knows the build dates of the affected engines, they wouldn't replace a failed one with another one built with the same suspect parts. Chances of a replacement engine having a major failure for any reason should be extremely low.

Yes, yes they would. It has already happened where a replacement engine failed because of the same issue.

Imagine getting a large batch of valve springs from the supplier. Then dumping valve springs into existing pile of valve springs that are waiting to be installed into new heads. How do you track which ones are bad and which aren't at that point? There are actually probably good ones in these batches from suppliers. They may not all be bad. There are very likely good mixed with bad.

Now, you have to source more good springs because you know you have an issue. Do you think that can happen in a day or two? No. It takes time to a)identify why the springs failed and then b)inform the supplier and get them to fix the issue with all new springs going forward.

So, there are probably a lot of heads that already have bad springs in them, including heads mounted on new warranty replacement engines. Gm has to try and figure out a)just how many of cars are really affected and b)the failure rate of those cars

As for build dates, the build date of the car isn't as important as the build date of the head and the engine.

[gtfoxy]

Originally Posted by Venomcustom

Awesome!! Looking forward to hearing how it is when you start really getting on it.

Manual shift mode is addictive as it’s so much fun.

Originally Posted by arpad_m

Yes, they put every single engine on a test bench that measures 1500+ parameters during a dry (compressed air) run, see below.

The pictures are from the LGX assembly line, but the process is likely very similar for the LT1 and the LT4.

Thanks!

[GearheadSS]

Originally Posted by SirJangle

Gotcha... I'm not one who's saying that it's a quality control issue per se. The issue to me is that they KNOW about this and are taking a wait-until-it-breaks approach. And, why wait until someone gets hurt and/or dies? GM knows about it NOW and should be proactive NOW.

Peace & Progress

Accept that this isn't at all what they're doing. This is just pure forum speculation.

They're not going to rush and just say replace every 6.2 valve spring until they get all of their facts and numbers. They MUST FIRST know exactly how many of them are affected and why it happened in the first place.

[GearheadSS]

Originally Posted by FH212

I have around 300 miles now. I am going to go for a few rides this weekend and get some more miles and see how it goes.

Get as many miles on it as you can now. The sooner you can get the mileage up, the more you can relax and feel better that you won't have an issue.

[ember1205]

Originally Posted by GearheadSS

Yes, yes they would. It has already happened where a replacement engine failed because of the same issue.

Imagine getting a large batch of valve springs from the supplier. Then dumping valve springs into existing pile of valve springs that are waiting to be installed into new heads. How do you track which ones are bad and which aren't at that point? There are actually probably good ones in these batches from suppliers. They may not all be bad. There are very likely good mixed with bad.

Now, you have to source more good springs because you know you have an issue. Do you think that can happen in a day or two? No. It takes time to a)identify why the springs failed and then b)inform the supplier and get them to fix the issue with all new springs going forward.

So, there are probably a lot of heads that already have bad springs in them, including heads mounted on new warranty replacement engines. Gm has to try and figure out a)just how many of cars are really affected and b)the failure rate of those cars

As for build dates, the build date of the car isn't as important as the build date of the head and the engine.

I find it hard to believe that any manufacturer would knowingly replace a failed major component with another that that had the same impacted parts and risk unless they did so without actually knowing of the risk. I understand what you're saying in regards to "dumping" the springs into a big pile and then essentially losing track of which are good versus bad, but to willingly swap in a motor with the same bad parts as the one they're swapping would be the dumbest decision on the planet - including from a financial standpoint. Even the bean counters would not support that.

[ember1205]

Originally Posted by GearheadSS

Accept that this isn't at all what they're doing. This is just pure forum speculation.

They're not going to rush and just say replace every 6.2 valve spring until they get all of their facts and numbers. They MUST FIRST know exactly how many of them are affected and why it happened in the first place.

They must also understand whether getting past a certain point means they are going to hold up or if there could still be an "early failure" at higher miles...

[cajunzl1]

These problems will never end in mass produced vehicles, including GM, back in the 70's it was nylon timing gear set failure, and bad camshafts, 90's had spring and axle issues in big trucks, fast forward to now, bad casting in oil pumps and bad valve springs.

My point is these parts in different variations have worked for many years without problems, its not like the engineers don't know how to design a reliable long lasting part, its that the bean counters are always riding them to make it cheaper or lighter.

Just saying....

[Petrol Head]

Some of you may be missing my point. I am not saying GM needs to replace the springs in all of them. Just the engines they know the defective springs went into. They know exactly which engine every spring went into and the VIN numbers of every car or truck those engines went into. Every part has a QR code that is scanned during assembly for situations exactly like this.