This M3 E90 belongs to @Etienne, a local member of EuroConnex with a well maintained, mint condition E90 M3.
This is his second E9X M3 and 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.
Let's get the obvious out of the way.
2x VANOS cover were warped already, and 2x broke off while removing them.
The guys at InnovAuto had previously done a washer installation to replace cracking VANOS covers on another E9X M3. They 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? Can't we run without it?
The picture below shows you why. The often referred "spring" is wrapped around the VANOS cam bolt. It isn't tied down to anything.
The plastic covers stops the springs from backing out during the movement of the Variable Valve Timing (VANOS) of the S65.
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!
Notice on the matching holes on the picture above. For the purpose of the picture, I aligned them next to each other.
You need to match this hole with the slightly protruding hole at 10-11 o'clock on the picture below.
A strong push is needed, but a re-assuring click is all you actually need.
It's going to feel intimidating at first, but worry not.
The Snap-In covers have one big guide tab that is machined to fit in one location. Align this and start pushing.
There are 6x snap-in tabs.
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.
Expect to have to push hard. Using a pry-bar's rubber handle helps for the last tabs. It gets harder as you snap more tabs in.