When I purchased my Z3 back in May of 2022, I had a state inspection done. They found the car to be in immaculate condition — except for the valve cover gasket. If you're in the BMW community, you know these particular engines leak oil. Over time, the gasket hardens from rubber to plastic, degrading the seal. Replacing these gaskets is just maintenance in my book, though others may call it a design flaw.
What tools do I need to perform the replacement?
You need very few tools to change the gasket — it’s surprisingly simple if you're comfortable working on your own car. If you can change your oil, you can do this.
Here’s what I used:
- Socket wrench (3/8")
- 10mm socket
- 8mm socket
- Flat-head (common) screwdriver
- RTV silicone
- (Optional) Milwaukee M12 3/8" ratchet — great for speeding up the process (don’t use it to tighten)
Removing the old gasket
Start by removing the oil fill cap. Then pop off the plastic caps over the engine cover bolts (shown as items 1–4 below). Remove the covers with your 10mm socket and set them aside.
Now you can access the coil packs and valve cover bolts. Using your 8mm and 10mm sockets, disconnect the grounding wires (circled as items 1–3 below). Then remove the bolts securing the coil packs (items 4–9). Two of the grounds are mounted to coil pack bolts.
I recommend numbering and organizing everything to make reassembly easier.
With the coil packs out, remove the 11 valve cover bolts using your 10mm socket (circled below). Discard the old rubber grommets — your new gasket should come with replacements.
Carefully and evenly pull the valve cover up. Don’t pry too hard — it's plastic and can crack. You may have to gently work around the perimeter a few times before it pops off.
Once removed, you’ll likely find a hard, brittle gasket. Snap it out in pieces and toss it. Inspect the valve train, camshafts, and coil packs while you’re in there.
Installing the new gasket
Reassembly is mostly the reverse of removal:
- Place the new gasket in the valve cover — it only fits one way.
- Dab RTV on the seams of the VANOS cover where the gasket will sit.
- Lower the valve cover carefully and evenly onto the head.
Install new grommets on the valve cover bolts. Insert the bolts by hand, then tighten using your socket until they bottom out. Work in a consistent pattern and give each bolt a final snug 1/8 turn.
(Reference the image above again for my tightening sequence.)
Reinstall coil packs and ground wires in the same positions. Then:
- Reinstall the engine cover with its 10mm nuts
- Replace the oil fill cap
You're done!
Congratulations — you just replaced the valve cover gasket! No more oil smell, and your Z3 is happy again.