My 6.5T has self destructed due likely to the heads and or block cracking, I am told that this is an inhearent problem with this engine and that most go at about 100,000 miles. I have been trying to get some info on upgrades that would prevent this from happening again and have been told that I have to get a new, high nickel content, block and heads that have a brass inserts to not have this very expensive problem again.
The local rebuilder/ diesel supplier tells me that this new block is the one that is used for the Hummer 6.5s and that it can be identified by a casting mark of ( I H ) found on the block below the intake manifold.
My problem is that General Motors doesn't seem to know anything about this different block and won't tell me, if I order the engine from them, what I will get.
Has anyone any more info on this mystery block or ideas about what would be my best bet for replaceing this engine?

You didn't list your year but I'd guess '97-'00 as these are the gernading veriety and the mechanic told you right as far as newer casts from hummer/AM general(did you call them?).
I think Kennedy sells them as well.

My 95 had a new longblock installed 2 months before I bought it. I have had it almost a year no major problems.... P.M. for more info...

I was under the impression from earlier questions a few months back that my 00 had the better block? Now QM your saying that isn't true?

Just be aware that a 'hummer' block is the same as the van setup, and is different from a 'pickup' block. Extra oil ports in the block for the center mount turbo, different intake manifolds, different heads, don't get the wrong one.

I was under the impression from earlier questions a few months back that my 00 had the better block? Now QM your saying that isn't true?
I've read that up to '04 could be a problem block at the H1 site.

Van setup has same alloy problems too?

:mad: :damnit1: :banghead: :rippedhan Censored

To Q.M. so you agree with the local guy that if I replace the engine with the new Hummer block/ modified heads engine that I can realisticly expect the engine to last alot longer than the old one?
do you know of any that have gone the long mile or is this modification an "on paper it should work" solution?
I seem to be looking at a repair bill of about 14,000 dollars total, lot of money for a maybe fix.
I appreciate your time and input.

The '97-'00 got oil spray channels, HO oil pump but for some reason alloy content was lowered previously. The Newer blocks have the oil channels but the alloy content is higher.
I think if you're willing to make the changes any 6.2L/6.5L will work, but it may mean heads, timing cover, oil line to turbo????
If I had deeper pockets I'd buy all the '97-'00 6.5's that came along with broken engine's and repower them. Cummins, 6.5L, whatever.

$14,000 CND? There's always a better deal if you research and do some work yourself.
Canadain rigger is up there in alberta with engine trouble too.

Tzingca

Check out DSG in Sask, i think if my problems are deeper than i want to go i may just get them to build me a complete engine. They have good pricing on the web.

The Newer blocks have the oil channels but the alloy content is higher.

As to the alloy content, How new QM?

When did AM general start making the 6.5L blocks? 2000? Google it.

QM are the 95 blocks prone to this as well ? ( L65 )

No, '95-'96 is solid.
'97-'00 has oil spray channels through the mains.

had me worryed there for minute with 92000 miles on it

Thanks alot guys.....I'm fixin to go to Mexico with my heavy 29ft trailer, and now I wont be able to sleep tonight (i leave tomarrow) thinking about my engine block. I have the 97 with 234,000so knock on wood.:eek:

However...If you think about it, that many miles is pretty good for a bunk block. All in all It boils down to maintanence/ driving habits. :thumb: