Crackin me up

[bradleyheathhays]

Me and the '96er ran into a guy the other day who had seen a lot of my same 4.0 engines. He had talked about showing me where the engine would first 'show a crack,' but unfortunately we never got around to getting the hood up. I'm guessing he was talking about the block but I'm not entirely sure. Have any of you seen enough of these engines to recognize a pattern in where a crack would start to show up? I'm at 173k mostly very easy miles so it probably wouldn't hurt to start keeping an eye out for something like this. Lord knows any more oil on the engine probably wouldn't get my attention.

 

[69jeepcj]

The engine block shouldn't ever crack from old age. antifreeze freezing in the block would do it, internal engine failure would do it, but I have never heard of it because of old age or high mileage.. I wouldn't worry about the block cracking.. I have a 52 year old engine in my jeep and it still running strong, very strong.

 

[superj]

not the block, never. I have seen heads crack from getting hot and the exhaust manifolds crack fairly easily, but never blocks. only when something comes free and a connecting rod whacks a hole in it but you will know what causes that when it happens. and its not from having lots of miles or old age.

I have had the 4.0 I6 with way over 300k in a number of jeeps. you have no worries with that engine

 

[78cj71ton]

Sent from my SGP561 using Jeepz.com mobile app

 

[JPNinPA]

Head crack on 331 stamp but not a block the only block issue I've read about was the rear freeze plug rotted out. I don't know the whole history but I'd think overheating and running water with no antifreeze would cause that easily. Or never changing the coolant and overheating.


Regards,
JPNinPA

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[78cj71ton]

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[bradleyheathhays]

Right on thanks for all the advice. Really good to know how solid this engine is.

 

[RestorationRides]

Head crack on 331 stamp but not a block the only block issue I've read about was the rear freeze plug rotted out. I don't know the whole history but I'd think overheating and running water with no antifreeze would cause that easily. Or never changing the coolant and overheating.


Regards,
JPNinPA

Sent using TapTalk

Just curious. What's a 331 stamp?

RR

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[RestorationRides]

I wonder where that crack blocked thing ever came from... it's amazing how much misinformation there is out there in the world...;-)

Two things that I know will crack heads and blocks. Insufficient antifreeze in below freezing temperatures and putting cold water in an overheated engine.

Other than that it would have to be a catastrophic mechanical engine failure, or an overstressed situation such as in a highly supercharged engine putting out multiples of the original horsepower it was designed for. Rest easy my friends.

RR

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[JPNinPA]

Just curious. What's a 331 stamp?

RR

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The heads are stamped with a design number. The 0331 design is almost guaranteed to crack.

Regards,
JPNinPA

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[superj]

that's true. forgot about those heads