2015 Denali-6.2L Broken valve spring

[07denaliyuk]

Just got the bad news, zero compression on cylinder 7 due to broken valve spring. Crap!
Intake side. 80k miles
Covered under warranty by it gives me concerns. Also, dealership says they can replace it without removing the head, how?

? are any others going to break?
? Anyone else have the same issue?

 

[iamdub]

The valve springs are on the topside of the head which makes them accessible simply by removing the rocker cover (AKA valve cover). I'd be concerned about damage to the piston if it contacted the valve.

No one without a magic crystal ball can answer if others will break.

Someone recently posted about engine trouble on a their 2015+, but I think it was a lifter failure. It would be something to Google for.

 

[swathdiver]

A lady just joined the forum and recently had a 6.2 that broke one of the #8 springs. One can examine the piston top through the spark plug hole with a bore camera.

I was surprised to learn that these engines have beehive single springs, all of my old GM cars from the 1970s through 1990s and I think even my 2000s GM minivans all use double springs. If one should break, the inner spring keeps the valve from kissing the piston and doing more damage. Never had one break.

Having learned that, I am considering double springs but the price is considerably more. Of course, should a spring break, they would seem a bargain!

 

[07denaliyuk]

If the valve dropped and contacted the piston it would likely be bent and they’d have to pull the head to replace it.

@iamdub; I understand getting to the valve springs, but don’t know how they would keep the valve closed while they compress the spring and inset the cap and lock without back pressure from the underside of the head. Maybe they use compressed air to hold up the valve while they do it. I’ve asked to see the opened up engine on Monday when they have the part, it had to be ordered in.

 

[jason952]

Yes , compressed air to hold valve closed


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[iamdub]

If the valve dropped and contacted the piston it would likely be bent and they’d have to pull the head to replace it.

@iamdub; I understand getting to the valve springs, but don’t know how they would keep the valve closed while they compress the spring and inset the cap and lock without back pressure from the underside of the head. Maybe they use compressed air to hold up the valve while they do it. I’ve asked to see the opened up engine on Monday when they have the part, it had to be ordered in.

There's a chance the spring broke but still kept the valve high enough to not drop onto the piston. Small chance, but the coils could've snagged each other. Yes, to replace the valve spring(s), they thread an adapter into the spark plug hole and blow air into the chamber to hold the valves closed.

I'd like to believe the dealership mechanic scoped the chamber during their diagnostics.

 

[AZRiverRunner]

The valve springs are on the topside of the head which makes them accessible simply by removing the rocker cover (AKA valve cover). I'd be concerned about damage to the piston if it contacted the valve.

No one without a magic crystal ball can answer if others will break.

Someone recently posted about engine trouble on a their 2015+, but I think it was a lifter failure. It would be something to Google for.

They can do a compression test to make sure the valve isn't damaged, you can have them use an optical scope through where the spark plug goes to view the piston and cylinder wall. As someone else said, you can pressurize the cylinder with air to hold the valve in place when they install the new spring/retainer/rocker arm.

 

[07denaliyuk]

Yukon is back in service and running fine. It was disappointing that it took a week to get the it completed. All 420 horses are working again.

 

[AZRiverRunner]

Great! Glad you're back up and running!

 

[Todd Gilkison]

Just got the bad news, zero compression on cylinder 7 due to broken valve spring. Crap!
Intake side. 80k miles
Covered under warranty by it gives me concerns. Also, dealership says they can replace it without removing the head, how?

? are any others going to break?
? Anyone else have the same issue?

Seems to be a more common issue then GM says. 2015 yukon with 70k miles just had broken spring on #2 intake. Lucky enough it held valve high enough from damaging piston. It did mess up valve guide. They are replacing head valve springs and 1 rocker. Mechanic made mention of Yellow top springs from factory, but they have changed them now to a blue top he thought. Still waiting on what GM sends to see. Sure tempted to change springs on other head.