Is this crack SERIOUS?
Le Mans Master
Joined: Aug 2005
Posts: 7,890
Likes: 0
From: FL
I dont see why the engine would need to be dismantled for welding
you could do small sections at a time when the car is completely cold and let it cool to make sure not to overheat the spot
the engine gets to 200 all the time so I dont think running some heat there for a few minutes will cause an issue
you could do small sections at a time when the car is completely cold and let it cool to make sure not to overheat the spot
the engine gets to 200 all the time so I dont think running some heat there for a few minutes will cause an issue
Pro
Joined: Oct 2003
Posts: 732
Likes: 2
From: Baxter MN
With ample respect to all the mechanics who understand these things better than myself, may I point out that he HAS an extended warranty. I would get that car down to my favorite GM dealer as quickly as I could and let them handle this. Even if he has a $500. deductible, that's a lot cheaper than the cost of a new engine & labor. Plus he gets the new engine warranty.
Drifting
Joined: Apr 2007
Posts: 1,496
Likes: 1
From: LEBANON PA.
Hi There:
Thanks for the better pictures.If this crack extended on each side of the of the knock sensor threaded inserts then you would have a real crack.This a surface crack which is caused by a too fast water quench of the casting, at the time of manufacture.For piece of mind buy the dye penetrant kit & verify.You can buy these kits from a welding shop.They cost about $20. Auto Zone may stock them.
If this should be a deep crack remove the head & have it welded by a certified aluminum welder.H e should show you his certification before doing the job.(Not anybody can do this type of welding.)Then do the ndi again on the weld before installation.
robsc501
Thanks for the better pictures.If this crack extended on each side of the of the knock sensor threaded inserts then you would have a real crack.This a surface crack which is caused by a too fast water quench of the casting, at the time of manufacture.For piece of mind buy the dye penetrant kit & verify.You can buy these kits from a welding shop.They cost about $20. Auto Zone may stock them.
If this should be a deep crack remove the head & have it welded by a certified aluminum welder.H e should show you his certification before doing the job.(Not anybody can do this type of welding.)Then do the ndi again on the weld before installation.
robsc501
Former Vendor
Joined: Jan 2008
Posts: 4,202
Likes: 1
From: Greenville SC
I have seen inside about 50 LS1 & LS6's and I have never seen this before, has anyone else seen this type of crack in this location before?
Also just the mention this again, the crack does go up and onto the machine boss area of the front knock sensor.
Also just the mention this again, the crack does go up and onto the machine boss area of the front knock sensor.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Former Vendor
Joined: Jan 2008
Posts: 4,202
Likes: 1
From: Greenville SC
as you guys can see in the second picture above, the crack does go onto the machined boss area, I was told by a machine shop today that if you can see that its for sure a real crack and not a casting mark, its very bad, because of were the crack is over the 2nd,3rd and 4th cam jurnal, that is super bad, has anyone every seen this before on a LS motor.
