2017 6.2L Defective Exhaust Valve

[Kardean]

I was wondering if anyone has had a valve stem break on the L86 exhaust valve.

[vinemann12]

What else broke with valve stem..

Did keeper and spring do any damage and whats piston damage...

 

Usually when this occurs,, damage will be expensive..

 

I have to ask,,norma driving or extended RPM??

 

Cheers----K

[newdude]

What cylinder was this from?

[Kardean]

Normal driving, truck has 2800 miles on it.

number 7 cylinder

here is the report from the dealer that worked on it.

 

VERIFY SES LIGHT ON.WOULD BARELY RUN TO BRING INTO SHOP.DIED

- ONCE IN SHOP.WOULD CRANK OVER & TRY TO FIRE BUT NOT RUN.SCAN

- TEST P0300 P0106 HISTORY.CHECK MISSFIRE DATA,SHOWS #7 & 8

- CYL SLIGHT MISSFIRE.ST TO CONTINUE DIAG

- CHECK SPARK,GOOD,MONIOTR FUEL PRESSURE,GOOD,FUEL RAIL

- PRESSURE GOOD.PULL FUEL SAMPLE,DOES NOT SHOW ANY WATER.ST 2

- TO CONTINUE DIAG

- DOES HAVE TICK NOISE FROM LHS WHEN ENGINE DOES RUN.

- VERIFY ENGINE RPM IN DATA WHEN CRANKING

- PULL #1 SPARK PLUG.VERY BLACK & SOOTY LOOKING.

- DISCONNECT EXHAUST,VERIFY IT RUNS & IDLES.DOES HAVE A ROUGH

- IDLE BUT NO MISSFIRES SHOW.

- WILL NEED TO REPLACE THE CAT CONVERTERS BEFORE ANY FURTHER

- DIAG

- REMOVED CATS.COULD NOT SEE ANY DAMAGE TO CONVERTER MATERIAL.

- CHECK ENGINE LIGHT ON WHEN BROUGHT BACK INTO SHOP.

- SCAN TEST P0300 #7 CYL MISSFIRE.

- REMOVED LHS VALVE COVER & FOUND #7 EXHAUST VALVE BROKEN.

- BORESCOPED CYLINDER,COULD NOT SEE ANY MAJOR DAMAGE.

- REMOVED LHS CYL HEAD.VALVE IS STILL IN HEAD.BROKEN END OF

- VALVE MUSHROOMED OVER SO IT WILL NOT COME OUT.NO DAMAGE SEEN

- ON PISTON.

- FILE END OF VALVE STEM TO REMOVE.

- COULD NOT SEE ANY DAMAGE TO GUIDE.P&A PARTS

- REPLACED #7 CYLINDER EXHAUST VALVE,SEAL,SPRING &

- RETAINERS.REINSTALL

[Justin101714]

Just seems like a mass produced part that failed. Don't foresee many of those going bad.

 

 

Sent from my iPhone using Tapatalk

[Krusty]

Normal driving, truck has 2800 miles on it.

 

 

Define "normal driving".... What kind of RPM has this engine seen?

[Kardean]

Normal driving... my definition is this truck was bought new with 35 miles on it my wife drove it for the first 1250 miles approx. 150 miles city driving and the rest highway not freeway.

I drove it pulling a fifth wheel with approx. weight of 5500lbs and truck weight of 6600 lbs for 1500 miles this truck has not seen any rpm over 4500.

I currently own GMC 2005 1500 6L with 220,000 miles and a 1994 GMC 2500 5.7L with 280,000 miles, all these trucks where bought new.

[combat1500]

Very bad luck!

[2017SierraSLT]

I'd say it could have been much worse If the valve had dropped, and contacted the piston.

[Half_ton]

my brother and dad both had this happen on their 6.2's. My dad's is a 2014 denali and brothers is a 2015 LTZ.

5.3 for me

[nitro882]

My 6.2 broke a valve spring on #7, valve was fine.. It ran but ran horribly, was down on power, shifted horribly and the dash lit up like a pinball machine. When it happened i literally had just pulled out of my driveway. Happened with ~25k on the clock, i have 60k now and no other problems since it was fixed.