Got an S54? You probably have a leaking little bugger...
One of the leaks from an S54 is when the Constant Pressure Valve (CPV) requires replacement. The CPV is located on the right side of the engine (behind the exhaust manifolds). The valve has an o-ring that tends to flatten and harden over time (and heat) and no longer seals adequately. Replacement of the valve takes about 1.5 hours (about 5 minutes when the factory headers are out).
Fortunately, this little valve is not too expensive, but you can make the replacement even better!
Solutions to a Potential Problem
By getting a replacement valve (BMW # 11 11 1 318 185), replacing the stock o-ring with the Rogue Engineering CPV o-ring will allow it to last longer than stock! When you take out the original one, the o-ring on the CPV is as hard as a rock, without elasticity. It cannot do the job of sealing up the engine block anymore.
The Rogue Engineering CPV O-Ring is made from Viton® fluoroelastomer with a temperature range of -40° to +400°F. This allows for a longer lifespan of the CPV (and less leaks!).
Currently, the replacement CPV O-Ring fit the following S54 equipped vehicles:
- 2001-06 E46 M3s (US or Euro)
- 2001-02 E36/7 MZ3 Coupe/Roadster
- 2007-08 E85 MZ4 Coupe/Convertible
When ordered alone, the CPV O-Ring is shipped uninsured and without tracking. It is mailed in an standard envelope. You are purchasing ONLY the O-ring, which does NOT include a factory CPV.