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GM service bulletin for faulty valve springs


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So I went in and talked to the service manager today. He didn't deny that he knew about the TSB. He said he has only had one that he had to repair so far. He said corporate GM said if a spring hasn't broke by 300 miles they probably won't break. 

He also said GM told them to run every new vehicle with a V8 for 4.5 hrs at 1800 rpm. If no springs break the the engine should be good to go. 

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54 minutes ago, Terry Swensen said:

So I went in and talked to the service manager today. He didn't deny that he knew about the TSB. He said he has only had one that he had to repair so far. He said corporate GM said if a spring hasn't broke by 300 miles they probably won't break. 

He also said GM told them to run every new vehicle with a V8 for 4.5 hrs at 1800 rpm. If no springs break the the engine should be good to go. 

Heard the same thing about running above idle to test.  Seems like "testing in production" to me, which is really the best way in many cases.  Problem is once they've rolled off the line, then the lot, costing the customer money, time, and risk that could be avoided.  General waste for everybody involved.  A good step, but would hope/think there would be a better way to identify which plants/batches installed in what engines and could be dealt with proactively.  Cost of doing business, I guess.

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1 hour ago, Larry CG said:

Heard the same thing about running above idle to test.  Seems like "testing in production" to me, which is really the best way in many cases.  Problem is once they've rolled off the line, then the lot, costing the customer money, time, and risk that could be avoided.  General waste for everybody involved.  A good step, but would hope/think there would be a better way to identify which plants/batches installed in what engines and could be dealt with proactively.  Cost of doing business, I guess.

It was all plants, I asked. They put out 65 trucks per hour per plant and I dunno what percentage have V8's. This was over a 105 day period according to GM. That's a lot of trucks and that's not including Cadillacs, Camero's Corvettes, Suburbans, Tahoe's etc.

Edited by Terry Swensen
Wrong word
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  • 3 weeks later...

2020 AT4, 6.2L, with around 7,000 miles (heres y'alls evidence for higher milage problems). I dont know the exact build date but purchased around 8/15/20.  Truck died at hwy speed on Christmas eve. Just got the call that a valve spring broke. I believe they said they're only replacing the one spring. I'm no mechanic so I just accepted it until I did a little homework. So from what I've read here, I should be asking for all springs to be replaced per the TSB?

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3 hours ago, tbbqwebber said:

2020 AT4, 6.2L, with around 7,000 miles (heres y'alls evidence for higher milage problems). I dont know the exact build date but purchased around 8/15/20.  Truck died at hwy speed on Christmas eve. Just got the call that a valve spring broke. I believe they said they're only replacing the one spring. I'm no mechanic so I just accepted it until I did a little homework. So from what I've read here, I should be asking for all springs to be replaced per the TSB?

To backtrack....

 

First, they should be scoping the cylinder to make sure none made it down that far/run a compression test

If all is good, then replace all springs

If there is cylinder scoring/compression loss, replace engine

Edited by Rob Mugs
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  • 2 weeks later...

Update - dealer did replace all valve springs without any encouraging from me. Fully covered under warranty. Took about 4 days to get the truck back.

 

*this post didn't quote. This is for the 2020 AT4, 6.2L, with 7,000 miles

Edited by tbbqwebber
Tried to quote post above but didn't. Edited for clarity
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On 1/12/2021 at 1:03 PM, tbbqwebber said:

Update - dealer did replace all valve springs without any encouraging from me. Fully covered under warranty. Took about 4 days to get the truck back.

 

*this post didn't quote. This is for the 2020 AT4, 6.2L, with 7,000 miles

Ouch.. 7,000 miles is a long time to be in the "unknown"

@kodiakdenali

 

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26 minutes ago, Rob Mugs said:

Ouch.. 7,000 miles is a long time to be in the "unknown"

@kodiakdenali

 

I'm having mine replaced, proactively, with aftermarket dual springs instead of factory style bee-hives. this whole thing stinks...but its not worth the stress of the unknown for the next 2-3 years (at the rate I add miles to my truck).

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  • 3 months later...

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