S54 timing chain guide

[bigjae46]

New BMW engines (like the N20) have plastic timing chain guides which wear and fail. The S54 has cast aluminum guides with a plastic liner. The only parts that go bad are the upper guide and the oil pump chain tensioner.

[Pklauser]

New BMW engines (like the N20) have plastic timing chain guides which wear and fail. The S54 has cast aluminum guides with a plastic liner. The only parts that go bad are the upper guide and the oil pump chain tensioner.

I recommend taking a look at the thread I linked. Only one of the guides is aluminum, and that plastic liner isn't immortal, a couple of us have had problems with it failing. Both guides on the exhaust-side are completely plastic, granted I haven't heard reports of the lower exhaust guide failing.