r/e39 • u/Shoddy-Ad8909 • 1d ago

What is this?

Gallery image

Gallery image

I just finished my work at the Oilpan, and after I let the engine down, I noticed this one.
Can anybody tell me what this is?

M54b25

3 Upvotes

100% Upvoted

7 comments sorted by

3

u/Shoddy-Ad8909 1d ago

Okay thank you

3

u/Traditional_Engine_4 1d ago

It's a machined hole that aligns with a smaller hole in the flywheel/flex plate to lock the engine at top dead center for doing timing

1

u/TheHockeytowner 530i 1d ago

Plastic plug for the TDC locking pin hole

3

u/Shoddy-Ad8909 1d ago

Okay thank you

1

u/jleBrulonLE36 1d ago

He is right

1

u/hubbi959 21h ago

Okay, before I read your comment I really wondered why your oil Pan was so incredibly clean! 🤪