"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 document my installation notes on a Etienne's E90 M3, a local member of EuroConnex."
This S65 barely had 45,000 miles
Etienne is on his second E9X M3: he knows what they need. The car is barely driven 4,000 km a year and oil changes are all done way ahead of schedule. The car has around 70,000km / 45,000 miles as it sits.
[...] and the covers were already warped.
The guys at InnovAuto had previously done a washer installation to replace cracking VANOS covers on another E9X M3. They knew what to expect.
2x VANOS cover were warped already, and 2x broke off while removing them.
The mechanics had this cardboard pre-folded to make sure no plastic pieces would fall into the engine.
You can see the warpage on the plastic cover on the right below.
Another angle, along with the cracked covers.
What is the cover's purpose again?
The picture below shows you why. The often referred "spring" is wrapped around the VANOS cam bolt.
The plastic covers stops the springs from backing out during the movement of the Variable Valve Timing (VANOS) of the S65. The bolt isn't tied down to anything.
Can't we run without it? No, you need something there or risk much bigger problems.
The snap-in metal covers are logical, somewhat easy [...]
The Snap-In metal covers mimic the Genuine BMW plastic snap-in mechanism. The OEM covers have slight plastic tabs to snap into the covers.
You wonder why BMW doesn't sell these separately knowing this.
[...] but it's still a 25,000$ engine!
You can mis-install these by forgetting to snap in a tab, or going too strong on one side and deforming another tab.
If you don't feel comfortable doing this, buy this for your shop to snap in while in there.
You need to match the Snap In cover's hole with the slightly protruding hole at 10-11 o'clock on the picture below.
Notice on the matching holes on the picture above. For the purpose of the picture, I aligned them next to each other.
A strong push is needed but a re-assuring click is all you actually need.
This video shows the proper installation steps, along with the sound to expect when properly clipping it in.
It's going to feel intimidating at first.
The Snap-In covers have one big guide tab that is machined to fit in one location. Align this and start pushing, make sure you do it parallel to the VANOS gear, and perpendicular to the ground.
Expect to have to push harder as you start going through each snap in action. Using a pry-bar's rubber handle helps for the last tabs. It gets harder as you snap more tabs in.
Being in the car, you can validate if your snap-in action was successful by using a mirror to look for the tab "grabbing" the VANOS. There are 6x snap-in tabs.
If you cannot see all the tabs, turn the crank over manually to spin the vanos gear. If you don't know how, you shouldn't be doing this yourself.
After witnessing this installation, I now firmly believe this is a no-brainer, while you're in there maintenance.
Considering the costs & risks involved: I have it on my to do list for 2023.
Skip this at your own risk! You can buy a set of CNC'ed Snap-In VANOS covers year long here.