More about "cracked" 6.5 heads that are still good...

[uglytruk]

A friend of mine just called to say his '96(?) 6.5 TD (4x4) has a blown head gasket. 170k. Xcab, longbed, consrutuction site beater, worked hard...
Assuming it is a head related problem, I recall reading a while back about 6.5 (& 6.2) heads that where discarded because of "cracks" that were just "superficial". Before the machine shop has him buy recons or spend money unessecarily, I will try a cooling system pressure test, (I have a pump).
Does anyone recall the thread, if in fact it's on this site? Truck is running, I've not been told what it is or isn't doing, yet. I am a (former) ASE mechanic...

 

[azblazor]

There are kits sold to put sleeves in the valve guides to prevent the crack propagation into a coolant passages. Some of the cracks are just superficial and don't continue. There is a lot of info on this issue over on www.thedieselpage.com