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I'm in the mist of replacing my head gaskets. The heads are down the shop being inspected as we speak. Does anyone have an opinion if the head bolts should be replaced? The machine shop said it was recommended, but the dealer said they never do it and don't stock them. I think it is common on certain vehicles due to bolt stretch and the steel just getting cooked next to exhaust ports and such.

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i didn't replace the head bolts when i replaced mine, and i think the gasket was going south again when i sold the car 30k miles later. i don't know if it was the block of not changing the head bolts that was the problem. might be cheap insurance if you plan to hang onto the car for a while...

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The steel bolts are a lot stronger than the aluminum engine is. The engines that require new bolts with every head removal have bolts that are required to be tightened to the yield strength of the bolts. Our bolts are not tightened that far, and will snap back to their original length when removed. As long as the threads can be cleaned and are intact, they should be reuseable.

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Consider the strength of an entire engine block, with steel cylinder liners, against the strength of a few bolts.

 

I know for a fact that my EJ22, 1990 model, used "stretch bolts". I am not saying that would make it fact that newer sube engines do so also, but new bolts are good insurance.

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Consider the strength of an entire engine block, with steel cylinder liners, against the strength of a few bolts.
A valid point in terms of 'global' strength. The failure however between an aluminum block and head bolts would most likely be 'local' in nature. The threads would strip out of the block before the bolt body itself would snap.

 

Commuter

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