"These build journal entries are part of a Special Series on the S65 VANOS covers failures, the available preventive solutions, and my unboxing & installation notes of the Snap-In Covers.
In this entry, I provide my research into the VANOS covers problem, how it came to light and the solutions available on the market."
- Matt
The documented case.
In 2021, a few S65 engine failures were reported with never seen before failure symptoms.
Ashton documented his catastrophic failure and engine rebuild process here.
The risks.
The culprit was diagnosed to the plastic VANOS gear covers. 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.
The probabilities.
It doesn’t appear to be nearly as prevalent as rod bearings. This does appear to be related to aging plastic components, and our cars aren’t getting younger.
Should you do this now?
I personally didn't. I feel it's a no-brainer while-you’re-in-there thing when considering the risks and slight additional cost to do this.
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.
My valve covers have started leaking a bit around 130,000km / 80,000 miles. I plan on doing the snap-in covers maintenance in 2023.
Can't you run the VANOS without the camps?
Short answer: no.
Technical answer: the cap stops these cam bolts from backing out.
It appears BMW didn't think they would fail. There is no part number listed by RealOEM for this and as such, they cannot be purchased separately.
Solutions.
VANOS Washers.
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. It's most often used by engine builders as a while you're in there during a rebuild. It isn't a DIY for most of us.
CNC'ed OEM style snap in covers
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. The price increased to 650$ for a while, and then came back to 450$.
No matter the cost, this is a smart solution as it recreates the OEM snap in mechanisms in a more durable material.
