BMW Engine Parts for BMW 1 Series

• All-in-one valve cover overhaul
• Preventative replacement saves time and trouble later on
• Includes new oil separator system
• Replace valve cover gaskets before a leak becomes worse
• Replace valve cover before it cracks

For the 2007 model year BMW switched to a plastic valve cover on the N51 and N52 engines. As we have seen over time the plastic can crack which leads to oil leaks, vacuum leaks, poor running, and other issues. Unfortunately, it's not just the gasket that needs periodic replacement but the entire valve cover itself. This kit includes a new valve cover, gaskets, eccentric shaft seal, and hardware. The valve cover also incorporates the oil separator which is not a replaceable item on its own. So a complete valve cover replacement will tackle multiple problem areas at once. The valve cover is the same for N51 SULEV and N52 engines.

Cracked Valve Cover. The plastic used for the N52 valve cover is thin and weak in certain spots. This makes it prone to hairline or larger cracks that will leak oil and cause vacuum leaks. You might also notice rough running, especially at idle. Often a technician will go looking for a failed ignition coil, spark plug, or failed vacuum hose on the engine. And without a fault code to assist in diagnosis this can often mean wasted time and money. A cracked valve cover is a new problem area that many techs don't think to check.

Oil Separator/Crankcase Vent. BMW integrated the oil separator system into the valve cover on these later engines. An internal manifold creates a cyclone effect and centrifugal force separates vapor from the liquid oil. The liquid oil is supposed to drain through the valve cover and back to the oil pan while the remaining vapor is burned up during combustion. It's a very efficient and environmentally-friendly design with very few moving parts. Unfortunately it's not perfect and eventually the internal passageways will become clogged. This problem is made worse in cars that have short drive cycles, sit for long periods of time, do not have frequent oil changes, do not see regular runs to redline, and cars in freezing climates. If the engine never reaches optimal operating temp the oil remains in liquid form or becomes sludge. This is bad news for the entire engine, leading to fouled spark plugs, rough running and misfires and even premature failure of catalytic converters and oxygen sensors. Since the oil separator system in the valve cover is not available on its own, and cleaning it is nearly impossible, the complete replacement of the valve cover is the only option. Other oil vent tubes and vacuum hoses are also recommended to get replaced at the same time.

Valve Cover Gaskets. As with any rubber part, failures occur when the rubber becomes dry and brittle. The pliable rubber no longer forms a seal between the cylinder head and valve cover where it will develop an oil leak. Valve cover gaskets that leak can allow oil to seep into the spark plug holes and contaminate ignition coil boots and plugs. That can lead to rough running and misfires. A new valve cover includes new gaskets.

Eccentric Shaft Seal. The seal for the eccentric shaft sensor is a known spot for oil leaks. When the seal to the valve cover fails oil can end up in the sensor itself and ruin the sensor (an unecessary $300 expense). Usually a new seal (o-ring) will stop the leaks but sometimes the valve cover is at fault too. A new eccentric shaft seal is included.

All new hardware is included to avoid re-using and over-tightening the original bolts (they have a very low torque rating).

Replacement requires accessing the rear of the engine with a lot of the upper plastic shrouding removed. The vent hose on the valve cover should be replaced as it is almost always broken anyway (#11157559528). The metal fuel line must also be removed and disconnected from the fuel injectors. Professional installation is encouraged if you have never done this kind of work before. Serious DIY types should have a Bentley Service Manual to use which greatly explains the process. You may also want to combine this work with the oil filter housing gasket replacement.

There is no maintenance or replacement interval for the N52 valve cover. However, we have seen cracks and other failures in the 50,000-90,000 mile range. Our best advice is to plan on a major top end overhaul around the 70-80,000 mile mark. There's no mechanical downside to replacing it as prevention and it will make the engine run better and last longer.

This item fits the following BMWs:
2008-2012 E82 BMW 128i
2007-2011 E90 BMW 328i 328xi 328i xDrive - Sedan
2007-2012 E91 BMW 328i 328xi 328i xDrive - Wagon
2007-2013 E92 BMW 328i 328xi 328i xDrive - Coupe
2007-2013 E93 BMW 328i - Convertible
2008-2010 E60 BMW 528i 528xi 528i xDrive
2011 F10 BMW 528i
2007-2010 E83 BMW X3 3.0i X3 3.0si
2007-2008 E70 BMW X5 3.0si
2007-2008 E85 BMW Z4 3.0i Z4 3.0si
2009-2010 Z4 BMW Z4 sDrive30i

Oil venting and circulation continues to be a problem on BMW engines and now even more so on the turbocharged N54 and N55 engines. The existing stock system does a very poor job of separating fluid and vapor and this leads to an oily film or even small pools of oil throughout the turbos and intake. We're seeing a lot more 135 and 335 cars with drivability and performance issues because oil has sneaked by the ring seals and is coating the intake piping, intercooler, intake valves, and other critical areas. The problem is worsened with higher boost levels. Oil is excellent for lubricating moving parts but terrible when it gets into the combustion chamber, effectively lowering the octane rating and reducing performance. Our own shop has gone the extra step and offers media blasting of the intake valves to strip away the oily buildup we have seen.

Our shop also strongly recommends an oil catch can be installed in the line for the crankcase vent. The oil catch can traps oil as it leaves the valve cover and holds it in a canister. Whatever minimal vapors are left over in the oil is then vented back through the canister and into the intake where it is safe to be burned up in the engine or recirculated back through the system again. This is the way the system was designed! At each oil change simply unscrew the canister and empty the trapped oil with your regular used oil. A dipstick is integrated into the cap so you can monitor the oil level. Installing one of these will avoid costly repairs in the future and help maintain your boost and performance. It's one of the smartest modifications you can make because it demonstrates a well-thought out tuning strategy and care for the condition of your engine.

The ECS Oil Catch Can is made from aluminum and with a stealthy black anodized finish. Multiple brackets are available so you're not limited on where to mount it. The location is key as heat will evaporate the oil and send too much vapor back into the engine (where cooler air will turn it back into fluid). The ECS OCC also has a factory-like appearance.

Note: Since the crankcase vent system is considered part of the overall emissions system, installing this may be a violation of local, state, and federal laws. While exemptions are made for track/race and off-road use, check with your local state inspection facility on using this in street-driven vehicles.

ECS Oil Catch Can Features:
+ Increases air intake efficiency
+ Promotes engine longevity
+ 4 chamber design promotes excellent air/oil separation
+ Large In/Out ports (no tapered sizes that slow flow)
+ Anodized black lightweight aluminum
+ Made in USA

This item fits the following BMWs with the N54 twin-turbo engine:
2008-2010 E82 BMW 135i
2007-2010 E9X BMW 335i 335xi
2006-2010 E60 BMW 535i 535xi