I have 2 sets of heads, both have hair line cracks between the valves at least in one spot. I have one shop that says they can fix them and another says there junk, buy new. I've also seen it somewhere on this forum that these are cosmetic and dont' worry about them. Help. 6.5td casting # 10137567

Generally these hairline cracks can be welded. Find a shop that is familiar with repairing diesel heads.

Do not weld - cracks can be cosmetic, can be permanently fixed with K-line K3900 repair kit

what is K-line K3900 REPAIR KIT ?

From Kline Industries, supplier to engine\head rebuilding shops - site address is on last page in coolant usage post by 94burb, or do a search for their site.


Rebuild shops should be familiar with the line.

How do you tell the difference between a cosmetic crack and something more serious?

Coolant leak will indicate very serious, but can still be repaired - fix is pressed-in sleeve across area of crack.


Cracks usually occur in cylinders 1,2,7,8 - the end ones, are usually considered as cosmetic with no leakage, but sleeve-repair fixes and prevents any further occurance.


Seems as tho GM addressed this problem in '97 with redesign and larger passage between the valve pockets providing better heat dissipation.