The S54 is one of the best engines BMW has ever made, but they do come with their fair share of issues. One of the biggest design flaws is the VANOS system and its many wear items. Catastrophic engine damage can occur if this system isn't properly maintained.
The problems inherent with the S54 VANOS are (from highest potential for failure to least):
- Camshaft gear bolts stretch slightly, loosen up, and allow play in the gear, causing the bolts to shear, the camshafts to stop moving, and your valves to become one with the pistons. Fix: replace the bolts every Inspection II
- VANOS oil pump drive teeth have excess play from the factory, and can snap off over time. Replacement drive hubs can cost as much as $1400! Fix: install Pavlov Racing pump shims to prevent excess movement and wear to the teeth
- VANOS oil accumulator hose pops, allowing high pressure (over 1500psi!) oil to be blasted all over your exhaust manifolds, potentially causing a fire. Fix: Leichtbau braided stainless steel hose
- Timing chain upper guide rail gets worn through and snaps into pieces. This doesn't necessarily cause any issues with running, but the broken piece can become dislodged and get caught in the timing chain or oil pump pickup. Fix: replace the guide every Inspection II
This is a full VANOS maintenance kit that should be done at the same time as the Inspection II service (every 60,000 miles). It also includes some upgrade parts - The VANOS oil pump drive shims, and the accumulator oil line - that have been engineered to last much longer than factory. These upgraded parts are so much better that we have yet to see them fail once, even with heavy track use.
This kit consists of:
Pavlov Racing VANOS oil pump drive shims (x2)
Leichtbau braided stainless steel accumulator hose
VANOS drive hub bolts (x12)
Cam gear bolts (x12)
Timing chain upper guide rail
VANOS gasket
All necessary crush washers