In 2021, a few S65 engine failures were reported and the culprit was diagnosed to the plastic VANOS gear covers.
Ashton documented his catastrophic failure and engine rebuild process here.
They appear to become brittle with age, and can crack. The plastic pieces end up in the pan and can block the oil pick up tube, leading to catastrophic engine failure.
I will not be a doomsday prophet. You manage your own risk.
It doesn’t appear to be nearly as bad as rod bearings.
This does appear to be related to aging plastic components, and our cars aren’t getting younger.
Do you need a cap?
Short answer: yes.
The cap stops the cam bolts from backing out.
Steve Dinan at Carbahn knew about this for a while and developed a simple washer and bolt solution.
It’s cheap, however it requires re-timing the S65.
Not a DIY.
A Russian company I personally dislike for piss-poor ethics & customer service introduced a smart solution DIY solution to allow snap-in CNC’ed covers.
They initially introduce the snap-in covers at 450$ and immediately notice demand was higher than they expected.
So they were 650$ for a while, and then came back to 450$.
It’s still too high.
Incoming EuroConnex curated product
These snap-in covers were retro-engineered by MPowerMotorsports and are made in the USA & Europe by Abdul and his team.
Valve covers on these engines are known to warp, the coating flakes and they need to be replaced.
BMW also had the brilliant idea to not allow us to purchase some hardware separately, the costs run high to do this service.
"For me, it’s a no-brainer while-you’re-in-there thing when considering the risks and slight additional cost to do this, while still being DIY friendly."
Glad to be working with a US company that’s willing to do the right thing for the community.