The crankcase ventilation filter traps oil mist before it enters your intake
Your 6.7 Powerstroke's crankcase ventilation system pulls gases and oil vapor out of the engine block so pressure doesn't build up inside. The crankcase ventilation filter — also called the PCV filter or breather filter — sits in that line and catches the oil mist before those gases reach your intake manifold. Without it, oil would coat your intake valves and turbo, and pressure would force oil seals to leak.
On the 6.7, this filter is a small cylindrical cartridge that lives in a housing on top of or near the valve cover. It looks similar to an air filter but is much smaller and filled with a finer media designed to separate oil from air. When it clogs, crankcase pressure rises, which can push oil past seals and into places it shouldn't be — your intercooler, intake, or even out past the turbo seals.
Most owners replace this filter every 50,000 to 80,000 miles, though some run longer depending on driving conditions. Severe duty — towing, dusty conditions, or short trips — shortens the interval. You'll know it's time when you see oil residue around the breather hose connections, notice a slight oil smell from the engine bay, or feel a loss of boost pressure.
Key Takeaways
- The crankcase ventilation filter separates oil mist from engine gases before they enter the intake, protecting your turbo and valves from oil buildup.
- On the 6.7 Powerstroke, this filter is a small cartridge housed near the valve cover and should be inspected every oil change.
- Replacement intervals typically fall between 50,000 and 80,000 miles, but towing or dusty conditions may require more frequent changes.
- A clogged filter causes crankcase pressure to rise, which can force oil past seals and into the intercooler, intake, or turbo.
- You can replace this filter yourself with basic hand tools in under 30 minutes if you're comfortable working around the valve cover area.
Where the crankcase ventilation filter sits on your engine
On 6.7 Powerstrokes built from 2011 onward, the crankcase ventilation filter housing is mounted on the driver's side of the engine, typically on or just below the valve cover. Ford's design uses a plastic housing with a spin-on or cartridge-style filter inside. The exact location varies slightly between model years — some sit directly on the valve cover, others mount to a bracket on the block — but all are accessible from the top of the engine without removing major components.
The filter connects to the PCV system via rubber hoses. One hose draws crankcase gases from the valve cover area; another line returns filtered gases to the intake manifold or air intake. A third line may vent to atmosphere on some years. These hoses are the first place you'll spot problems: if they're wet with oil or smell strongly of fuel and oil, the filter is likely saturated.
Before you start any work, locate your specific filter housing by checking your owner's manual or a service diagram for your model year. This takes 30 seconds and prevents you from removing the wrong component. The housing itself is usually held down by one or two bolts and comes free easily once you disconnect the hoses.
How to tell if your filter needs replacement
The most reliable sign is a visual inspection. Remove the filter housing and look at the cartridge inside — if it's dark brown or black instead of white or light tan, it's saturated with oil and needs to come out. You don't need to wait for symptoms; checking it during every oil change takes 10 seconds and prevents pressure buildup before it causes damage.
Symptoms of a clogged filter include a slight oily smell from the engine bay, especially after the engine cools down. You may also notice a thin film of oil around the hose connections where they attach to the housing, or oil residue on the outside of the turbo. In more severe cases, a very clogged filter can cause a slight loss of boost pressure or a rough idle because crankcase pressure forces oil into the intake.
Mileage is a rough guide, but condition matters more. If you tow regularly, drive in dusty conditions, or make frequent short trips, inspect the filter every 30,000 miles. Highway driving with longer intervals between oil changes may stretch it to 80,000 miles. When in doubt, pull the housing and look — the filter costs $15 to $40, so replacing it early is cheap insurance against turbo damage.
Steps to replace the crankcase ventilation filter yourself
You'll need a socket wrench set, a small flathead screwdriver, and a clean rag. The job takes 20 to 30 minutes and requires no special tools. Work on a cold engine to avoid burns from hot metal or hoses.
- Locate and access the housing. Find the filter housing on your driver's side valve cover area. You may need to remove the plastic engine cover or air intake hose to reach it comfortably, but this is optional if you have room to work.
- Disconnect the hoses. Gently twist and pull the rubber hoses off the housing. There are usually two or three connections. Mark them with tape or take a photo so you reconnect them correctly. A small amount of oil may drip, so have a rag ready.
- Remove the housing bolts. Use your socket wrench to remove the one or two bolts holding the housing to the valve cover or bracket. Set them aside in a safe place.
- Separate the housing halves. The housing is typically two plastic pieces held together by bolts or a clip. Remove these fasteners and carefully pull the halves apart. The old filter cartridge will be inside.
- Remove the old filter and clean the housing. Pull out the old cartridge and wipe the inside of the housing with a clean rag to remove any oil residue or debris. This prevents contamination of the new filter.
- Install the new filter. Insert the new cartridge into the housing, making sure it seats fully. The cartridge should fit snugly with no gaps around the edges.
- Reassemble and reconnect. Put the housing halves back together and tighten the fasteners. Reconnect the hoses in their original positions — if you're unsure, refer to your photo or manual.
- Reinstall the housing. Bolt the housing back to the valve cover or bracket and tighten firmly but not excessively — you can crack plastic if you over-torque.
- Start the engine and check for leaks. Run the engine for a minute and watch for oil seeping from the hose connections. If you see drips, shut down and reseat the hoses or housing.
What filter part number to buy for your 6.7
Ford's OEM part number for the crankcase ventilation filter cartridge is BC3Z-6N635-A for most 2011–2024 model years. This is the filter element only; if your housing is damaged or the seals are worn, you may need the complete housing assembly, which is BC3Z-6N634-A. Always verify your specific year and engine configuration before ordering, as some variants exist.
Aftermarket options from Motorcraft, Fram, and other suppliers are available and typically cost $15 to $30. OEM filters run $25 to $40. Both work well; the difference is mainly brand reputation and availability. Many diesel shops stock these filters, so you can often pick one up same-day rather than waiting for shipping.
When you order, confirm the part fits your model year. The 6.7 Powerstroke has been in production for over a decade, and while the filter design is consistent, there have been minor updates. Your VIN or the service label under your hood will tell you the exact year and configuration if you're unsure.
Why this filter matters for turbo and intercooler health
The crankcase ventilation system is one of the most overlooked maintenance items on diesel engines, yet it directly protects two of your most expensive components: the turbocharger and intercooler. When the PCV filter clogs, crankcase pressure rises and forces oil into places it should never be. Oil in the intercooler reduces cooling efficiency and can eventually clog the core. Oil in the turbo bearings causes them to wear faster and can lead to catastrophic turbo failure.
A clogged filter also allows oil vapor to condense inside the intake manifold, coating the intake valves with carbon and oil residue. This reduces airflow, lowers boost pressure, and can cause rough idle or hesitation. Over time, this buildup hardens and becomes difficult to clean without removing the manifold.
The good news is that a $30 filter replaced every 50,000 to 80,000 miles prevents all of this. It's one of the cheapest preventive maintenance items on your truck and one of the most important for long-term reliability. Skipping it to save money almost always costs far more in turbo repairs or intercooler replacement down the road.
Frequently Asked Questions
Can I drive with a clogged crankcase ventilation filter?
Yes, but not for long. A clogged filter causes crankcase pressure to rise, which forces oil past seals and into the turbo, intercooler, and intake. You'll notice a loss of boost and oil smell within a few hundred miles. Continuing to drive risks turbo damage, which costs $1,500 to $3,000 to repair. Replace the filter as soon as you notice symptoms.
How often should I check this filter?
Inspect it every oil change — it takes 10 seconds to pull the housing and look at the cartridge. Replace it when it turns dark brown or black, or every 50,000 to 80,000 miles, whichever comes first. If you tow or drive in dusty conditions, check every 30,000 miles.
What happens if I install the hoses in the wrong order?
The hoses are designed to fit specific ports on the housing. If you reverse them, crankcase gases won't flow correctly and pressure will build up. The engine may run rough or lose boost. Take a photo before disconnecting, or mark the hoses with tape so you reconnect them in the correct order.
Is this a job I should take to a shop instead?
No — this is one of the easiest filter replacements on the truck and takes 20 to 30 minutes with basic hand tools. A shop will charge $100 to $150 in labor, while the filter itself costs $15 to $40. Doing it yourself saves money and lets you inspect the hoses and housing for damage at the same time.
Can a clogged PCV filter cause white smoke from the exhaust?
Not directly, but it can contribute. A clogged filter forces oil into the intake, which can burn in the combustion chamber and produce a slight haze. More commonly, white smoke indicates coolant in the cylinders or a failing injector. If you see white smoke, replace the PCV filter first, then have a shop diagnose the exhaust if the smoke continues.