Are almost all 300D head gasket failures caused by overheating?

[PreferVintage]

If one is to believe Kent Bergsma from MB Source, virtually all head gasket failures with our diesels can be traced to an engine overheat at some point...is that true? He sells a video on-demand I'm not sure is needed. Or can a gasket fail just due to our cars getting older, or due to something else?

[Diseasel300]

Overheating is probably the most common cause of blown gaskets, but they can fail randomly from age or usage too. Gasket failure isn't that common on the 61x's but it happens. Head gasket failure is probably more common on the 60x series engines since they use an aluminum head on iron block (causes scrubbing) and have a stupidly designed exposed oil gallery by Cylinder 1 in early head revisions.

[Diesel911]

I have scene head gaskets leak due to pitting caused by depletion of the rust prevention of the coolant (electrolysis?) and an article I read said that the while we don't think of it the heating and cooling of the parts causes movement due to expansion and contraction although the term scrubbing was not mentioned that is what is what I am guessing they were speaking of.

On Big Rig Diesel Truck Engines I have seen the occasional head bolts fail. So head bolts can fatigue and lose their elasticity and cause head gasket leaks.

I have also seen one Diesel Head Gasket were the Injector spray (this was a direct injection engine) was not good and focused on part of the head gasket that burned through and leaked coolant.

[Diesel911]

I have scene head gaskets leak due to pitting caused by depletion of the rust prevention of the coolant (electrolysis?) and an article I read said that the while we don't think of it the heating and cooling of the parts causes movement due to expansion and contraction although the term scrubbing was not mentioned that is what is what I am guessing they were speaking of.

Also Cylinder heads and blocks can warp from normal use. If you look inside of cylinder heads and blocks the thickness of the metal is often not very evenly distributed. That means inside of say a block more metal might surround one side of a cylinder then the other side. That means heating and cooling cycles are going to stress the block and distort slightly. The same with the inside of the cylinder head.

On Big Rig Diesel Truck Engines I have seen the occasional head bolts fail. So head bolts can fatigue and lose their elasticity and cause head gasket leaks.

I have also seen one Diesel Head Gasket were the Injector spray (this was a direct injection engine) was not good and focused on part of the head gasket that burned through and leaked coolant.

Getting back to Kent. If you own a Car long enough thermostats sometimes fail to open and fan belts break and you can experience coolant leaks that over heat your engine but don't do obvious damage but in particular stress the cylinder head. So an accumulation of small stuff and time can do in a head gasket.

The pic is from a gasoline engine of mine. The threads of the Head Bolts on the Engine are exposed to the coolant and over Time the Coolant seeped up past the thread sealant and into and next to the head gasket and corroded under the sealing area and got into the combustion chamber.

Notice that the head surface has been cleaned and some surfacing done to it but the pitting is still there. There was also another area of pitting on the other head that was not as deep.

[barry12345]

Head gaskets can rot with age. The 616 and 617s seem to have head gaskets that have aged well so far in general. I have no way of being certain. Still I would suspect that three of my old 616 qnd 617 engines still have their original head gaskets.

Cast iron head and block really limit the dissimilar metals expansion issue effect.

[t walgamuth]

The 617 turbo seems to wallow out head gaskets before 300K miles, leading to leakage. A lot of extra heat from the turbo probably makes things move around more.

[moon161]

Kent's stuff can be detailed and useful, especially if you need a complete step by step on a repair. I think I may have got the booklets for 61x valve guide seals, and the 61x front main seal and they were pleasantly complete.

Some of his stuff is just trying to find out how many ways he can pitch lubro moly diesel purge.

Beyond supporting the uncontroversial idea that head gasket failures probably traceable to engine overheats, I'd hope a related video went into detail on cooling system maintenance. I'm betting 9/10 he pitches a citrus flush kit and instructions in the video.

[renaissanceman]

My favorite video from Uncle Kent is still the one where he says off brand "hi-temp" vegetable oil fixes low compression.

Shark jumped, in my book.

[martureo]

Originally Posted by Diesel911

I have scene head gaskets leak due to pitting caused by depletion of the rust prevention of the coolant (electrolysis?) and an article I read said that the while we don't think of it the heating and cooling of the parts causes movement due to expansion and contraction although the term scrubbing was not mentioned that is what is what I am guessing they were speaking of.

On Big Rig Diesel Truck Engines I have seen the occasional head bolts fail. So head bolts can fatigue and lose their elasticity and cause head gasket leaks.

I have also seen one Diesel Head Gasket were the Injector spray (this was a direct injection engine) was not good and focused on part of the head gasket that burned through and leaked coolant.

This isn't possible. Bolts don't "lose elasticity." The heat loading of the bolts isn't a concern either.

I'll quote myself from when this came up a year or so back.

Originally Posted by martureo

...

No, the torque will not be changed noticeably by the thermal expansion of the aluminum head. The expansion we are talking about is a few thousandths of an inch anyway. The bolt is taking the majority of the load as its stiffer than the head.

So, yes there is some weakening of the bolt, but if the engine has already seen 100,000+ miles of cycling and the bolt have not broken or failed at this point there is little reason to assume that they will unless there is an anomaly in the future.

Additionally, while there is some loss of torque after the first engine test in the factory, the torque is pretty constant after that. Torque doesn't slowly drop off through dozens of cycles on a bolt that was torqued to yield. If the torque started to drop it would drop to zero and the bolt would back out rather quickly.

And all of this happens in an environment where the bolts are significantly stronger than they need to be, of better steel than they need to be, etc. The bolts have a significant margin of safety and, as I said before, unless there is an anomaly such as widespread overheating or lack of oil (neither of which would hurt the bolts before hurting the head) nothing is going to change between 100,000 miles and 200,000 miles.