BMW PCV Valve – Crankcase Ventilation / Oil Separator – M54 and M52TU 6-Cylinder
What’s the maintenance schedule for pcv valve on my 2002 x5 3.0i, and 1999 323i 4door? Why don’t I see this as a maintenance item anywhere? It went on both my cars at around 50,000 miles. The x5 cost a bundle to repair at the dealer. The car blew smoke from the exhaust and had to be towed.
The crankcase ventilation system, on later model 6-cylinder BMWs, is indeed a trouble area (as it is on the V8 models, as well). We haven’t yet taken to suggesting that replacement of all of the hoses and the oil separator be a periodic maintenance item. We typically get into the system when we see the symptoms appear, such as; oil burning, rough idle, engine fault codes that suggest air/fuel mixture problems or oxygen sensor problem and other symptoms that would suggest vacuum leaks in the system’s ventilation hoses or a ruptured check valve diaphragm. As with your cars, we are seeing these systems having trouble at mileages between 50,000 and 100,000.
(EDIT – 02/2011) – At this time, four years after this was written, we would now certainly recommend a preventative maintenance replacement of the PCV system on these engines. We are seeing practically all of the M54 and M52TU applications having failed PCV systems in the 60,000 to 150,000 mile ranges. Considering the potential for catastrophic engine damage, we fully recommend a 60,000 to 80,000 mile replacement . We have even had customers who require annual replacement due to sludge build-up.
Most (if not all) US model M54 engined BMWs were delivered with the standard warm weather systems. The kits that we offer, include the hoses and valve assembly from the “cold weather” package. The hoses and valve are insulated with molded foam insulation. This can help to prevent the build-up of condensation in the hoses and the separator valve (which leads to sludge build-up and possible clogging of the ventilation hoses, valve or the oil drain hose). Even if you do not live in the northern climates, these parts are a good choice and will help to prevent the sludge build-up in the system.
See the link below for a DIY on replacing the Crankcase Ventilation System parts: