Motor won’t turn over – any suggestions?

[Philo Beddoe]

Hi all, searching for some technical help.

I just bought a 1999 Boxster – manual with 86k and the motor won’t turn over. With a breaker bar, the engine will spin ~ 90 degrees and then locks. It will move 90 degrees counter clockwise and then 90 degrees clockwise. Cannot complete a revolution.

Diagnosis:
Oil filter is clean. Oil pan had a very very small piece of the guide.
No damage to the plugs – & they look good.
Dropped the motor and pulled the rocker covers off, and everything appears be clean and good.
Used a borescope and wasn’t able to see anything in the cylinders.

I don’t believe it’s an IMS issue as I would expect to see some carnage. It feels like it may have jumped a tooth?

Next step will be to pull the cams to see if it will turn over with the cams out.

Has anyone seen this before?

Appreciate any advice on what to check next.

Thanks,
Philo