95 Burb 5.7 TBI rattle when warm under load at specific rpm

[HDburb]

Had the same thing on my 92 suburban.... almost sounded like the bottom end was out of it. Compression tested... thought it was odd I had two dead cylinders side by side... did a cylinder leak down confirmed the air flow between the two... changed the head gaskets... and now it's all better.

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[Schurkey]

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When mine did that, it gouged the block and the head. Wasn't just the gasket that got blowtorched.

 

[HDburb]

When mine did that, it gouged the block and the head. Wasn't just the gasket that got blowtorched.

I got very lucky and caught mine in time. No damage to the block or head.