If you own a BMW E39 or E46 you probably know all about oil leaks. While these are amazingly fun cars to drive, there is a fair amount of attention that has to be paid to maintaining these German Ultimate Driving Machines.
While some of the more common oil leaks include valve cover gasket, oil pan gasket, and oil filter housing gasket, my 2004 BMW 325iT Touring Wagon with 215K miles (rare manual transmission) has developed a not so common Exhaust Vanos Solenoid Valve oil leak.
The VANOS solenoid is a solid piece of hardware that rarely goes bad, however after many years and over 200K miles, the oil pressure eventually wears the device out and oil begins to leak inside the connector. It’s probably more common for the O-ring to go bad, however I actually have oil inside the connector which indicates the solenoid needs replacement.
Another common cause for oil leaking on this radiator hose located at the front passenger side of the E46 M54 engine is a bad O-Ring on the Exhaust Cam Position Sensor. The part# for this O-Ring is # 12141748398. The Exhaust Cam Sensor is # 12147518628.
However, in my case, the Exhaust Vanos Solenoid Valve part# 11361432532 needed to be replaced to solve the oil leak even though I had no other codes or issues. If it was the Solenoid O-ring that needed replacement, the part number is # 11361703713
And yes, the new vanos solenoid does come with the O-ring:)
YouTube Video Link for this E46 ZHP Wagon Project Car