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Several months ago, our Civic developed a vibration. The intensity of the vibration has slowly worsened over time. From outside near the engine compartment, it sounds fairly normal for a vehicle with 140K miles on it. From inside the cabin, it's almost unbearable. An intense vibration that shutters your bones like a deep base speaker turned up high. It's worse at start-up when cold. It improves a little bit when warm. It's worse when warm in PARK and REVERSE.

Vehicle background. Ours was one of those where the block cracked. Honda replaced it with a brand new motor (they used the existing head) at 95K miles. So the new motor block has about 45K miles on it.

Our mechanic first replaced the belt tensioner. No improvement. Next, he replaced the main motor mount. Maybe a minimal improvement, undecided on that. It drives fine and as expected for it's odometer reading but the vibration needs to go. We have decided to stop pouring money into it until we have a better understanding of what needs to be done. And so, I come to you come for advice. Please help. Thanks!

 
Rep Power: 222

Check the engine mounts, one of them tends to collapse.