For what it's worth, I had a balance shaft/oil pump belt break and get caught up in the timing belt on my '94 Galant. This caused the timing belt to skip several teeth (who knows how far) and bent all the valves. It left damage on all pistons, somewhat similar to the damage I see here. I smacked a head on it from the junk yard and proceeded to drive it another 15k miles without any related trouble.
Reviews of Mitsuboshi pistons
3 votes
1 review
What we know about Mitsuboshi pistons
The brand is registered in Japan. Official website: http://mitsuboshi.info/.
In March 2026, PartReview does not yet have a formed opinion of Mitsuboshi pistons. You can help by adding a review for Mitsuboshi pistons.
Currently there are 1 review and 3 votes. Average rating — 4 out of 5. Vote balance: 3 up, 0 down.
Users also evaluated the qualities of Mitsuboshi pistons:
- Power - engine feels weak, especially under load - rated positively. 4 points out of 5.
- Smoke - blue smoke indicates oil getting past pistons - no rating yet
- Noise - deep knocking under heavy throttle is a danger sign - no rating yet
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