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Cylinder Heads/Cracking:

> I bought a '95 NA diesel wagon last December(1997). Before purchasing it, I
> requested and received from the dealer, the vehicle's service history. In
> Sept/97, the right cylinder head was replaced since it was cracked. Both
> right and left head gaskets were replaced at that time.  Well, I've just
> replaced the left cylinder head because it was cracked. I have been
> following the HML for some time and I do not recall seeing any threads on
> cylinder heads and their propensity to crack. The dealer claims that it is
> a very rare situation to have cracked heads. Other users of the GM 6.5L
> diesel (Suburbans, GM trucks) tell me it is all too common.
> My question: Have others had a problem with cracked heads?  Is it common or
> rare?
> Thanks.
> Richard Oatway


I too have heard that cracked cylinder heads are a faily common occurance on Chevy 6.5 (and 6.2) diesels. Do your cracks appear between valves on the end cylinders at the thinnest portion of metal? . (These cracks are often not very deep and do not enter the water jacket.) I would be willing to guess that this is the case.

If so you might be able to fix them rather than shell out close to 750 per head. Give K-line a call at 616 396 3564 and ask them about kit KL3900. Essentially what it does is inserts a cylindrical tube in the water passage below the crack which gaurantees that compustion products will not enter the cooling system. Its a little difficult to explain with a picture, but I've done this to two chevy trucks of mine and have had great success. I believe that some time in 1997 chevy redesigned the cylinder heads to incorporate larger ports for coolant flow, which in turn resulted in less of a tendence for the heads to crack in the area mentioned. If you do replace heads, try to go to the newer 1997 plus models.


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