[Obioban]

Originally Posted by ClarkeBurns

Ian-

From what I've read, the vanos bolts are unfortunately only the fixable half of the E46 vanos conundrum. You are more knowledgeable than I, but it sounds like the teeth on the exhaust cam are known to simply snap off, grenading the engine. Not as common as the bolts backing out, but equally catastrophic and not really fixable (metallurgical issue).

The intake bolts are the ones that have the issue. i haven't seen any examples of the exhaust bolts breaking/sheering/backing yet.

The intake bolts can be replaced with the updated part, but it is expensive if you don't DIY. $8 if you do DIY, though .

It is only half the VANOS issue, but it's the half the can cause really expensive repairs/engine failure. The other weak point is the VANOS solenoid, but it does no damage when it goes, is an easy fix, and rarely goes.

[ClarkeBurns]

What about the few cases where the gear teeth themselves shear off? Seems like mostly 04s

[CatchMyM3]

Originally Posted by ClarkeBurns

What about the few cases where the gear teeth themselves shear off? Seems like mostly 04s

I think you mean the cam gear prongs that drive the VANOS oil pump? Yeah, I think I've seen 2 reports of at least 1 prong shearing. That seems to be even more rare.