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Old 03-11-2019, 11:39 AM
More Power's Avatar
More Power More Power is offline
Join Date: Feb 2000
Location: Montana
Posts: 10,655
Arrow Reliability of Head Gasket Repair

Diesel engines can be hard on head gaskets. I get asked about the reliability of head gasket replacements from time to time, and I have to answer them by saying I don't really know what the big picture is, only what I personally know about it.

So, here is a topic thread where we can hopefully learn more about a broader spectrum of repair situations, and what real owners have experienced during their owning the same truck before/during/after a head gasket replacement.

Have you had the head gaskets replaced on your Duramax? What year truck, how many miles before the problem and then after the new gaskets have been replaced. Were there any performance mods on the truck?

Do you believe head gasket replacements are reliable? Share your experiences. The bottom line is... is a head gasket replacement reliable over the long-long haul? Thanks, Jim
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Old 03-11-2019, 06:35 PM
rapidoxidationman rapidoxidationman is offline
Join Date: Dec 2002
Location: Teton Valley, Idaho
Posts: 1,903

26 December 2011 - 9 January 2012 (yeah, it took me 60 hours instead of the 40 hour book time but dammit Jim I'm a handyman not a diesel mechanic!)
147,950 miles
replaced both head gaskets (a problem since truck was new to me with 123,500 miles)
redecked heads, cleaned heads, reground valve seats, valves
replaced valve guides and seals
replaced water pump
replaced steering column intermediate shaft
replaced fuel filter

then, a few miles later...

21 June 2012
155,310 miles
Replaced water pump (again)
Replaced passenger side head gasket
reground passenger side head and valve seats
(spun shaft on GM water pump caused overheating)

Full disclosure: When I replaced the head gasket on the passenger side the first time, one of the ARP head bolts I used didn't seat properly. That didn't have anything to do with the water pump defect overheating the engine, but I thought the engine had overheated BECAUSE of the improperly installed bolt. So I took that side apart and replaced the head gasket again and the bolt got installed properly this time. Guess what? The truck still got too hot. So I stuck a camera up the water pump's inlet hole and discovered that the impeller was freewheeling on the shaft. Replaced the water pump with another new one and all has been well in that regard up to and including now (253,000 miles and change). The only repair related issue (and it was totally my fault) was a few thousand miles ago when I started dumping coolant out a cracked rubber line that goes between the top radiator metal line and the turbo(?). When I removed and installed that fitting the rubber line is attached to, I twisted the hell out of the line. Rookie move that lasted until a few months ago, and it was fairly easy to replace once I found the issue.
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Old 03-12-2019, 10:17 AM
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More Power More Power is offline
Join Date: Feb 2000
Location: Montana
Posts: 10,655

Originally Posted by rapidoxidationman View Post
.. clip...all has been well in that regard up to and including now (253,000 miles and change).
Thanks for your input. So, it sounds as though there has been almost 100K miles put on the truck since the head gasket replacement - without a repeat. That's good news.

I know of some Duramax owners who, through the years, traded trucks when faced with a significant service problem (LMM injectors in one case and head gaskets in another). This punted the problem, and didn't improve our understanding of the permanence of costly repairs.
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