6.7 Cummins CCV Filter Replacement: What You Need to Know

The 6.7 Cummins is a workhorse diesel engine found in Ram 2500 and 3500 trucks, and like all diesel engines, it produces crankcase vapors — oily blow-by gases that escape past the piston rings during combustion. The Crankcase Ventilation (CCV) filter is what captures those vapors before they're recirculated back into the intake. When it clogs, you'll know.

What the CCV Filter Actually Does

Diesel engines don't vent crankcase pressure directly to atmosphere. Instead, a closed crankcase ventilation system routes blow-by gases back through the intake to be burned off. The CCV filter sits in that loop and traps oil mist and soot before the vapors reach the intake manifold, turbo, and intercooler.

On the 6.7 Cummins, the CCV filter is housed in a canister-style assembly typically mounted near the valve cover or on the side of the engine block, depending on the model year. The filter element itself is a coalescing media — it collects oil droplets and drains them back into the crankcase.

When this filter becomes saturated and restricted, pressure builds in the crankcase. That pressure has to go somewhere.

Symptoms of a Clogged CCV Filter

A neglected or failed CCV filter produces recognizable symptoms:

• Oil leaks at gaskets, seals, or the dipstick tube — crankcase pressure forces oil past weak points
• Black soot or oily residue in the intake piping or around the air filter
• Rough idle or black smoke from excess oil vapor entering the intake
• Oil being pushed out of the breather or onto the engine exterior
• Check engine light in some cases, particularly if MAP sensor readings are affected

These symptoms don't confirm a CCV issue on their own — other problems can produce similar signs — but a restricted CCV filter is a common culprit on higher-mileage 6.7 Cummins engines.

Replacement Intervals: What's Generally Recommended

Cummins and Ram have published service intervals for the CCV filter, though these vary by model year and duty cycle.

⚠️ These are general reference points. Your actual interval depends on your specific model year, how the truck is used (towing heavy loads increases blow-by), and whether earlier symptoms appear. Always cross-reference with your owner's manual or the factory service documentation for your specific year.

Trucks used for heavy towing, high-idle work, or diesel performance modifications may need more frequent changes. Some owners on modified trucks — with upgraded fueling, larger injectors, or tuning — report needing replacements well ahead of the factory schedule.

How the Replacement Process Generally Works

The CCV filter on the 6.7 Cummins is considered a DIY-accessible service item for most owners with basic mechanical confidence. The general steps involve:

1. Locating the CCV canister (position varies by model year — earlier generations have it on the passenger side of the block; later versions differ)
2. Disconnecting the crankcase vent hose(s)
3. Unthreading or unclipping the canister housing
4. Removing the old filter element and draining any collected oil
5. Installing the new filter element and reassembling the canister
6. Reconnecting vent lines and checking for leaks

🔧 The hoses and clamps connected to the CCV system are worth inspecting while you're in there. Cracked or oil-soaked vent hoses are common on high-mileage engines and are inexpensive to replace at the same time.

What the Job Costs

Parts cost for a replacement CCV filter element typically runs in the $20–$60 range, though this varies by brand (OEM vs. aftermarket), supplier, and region. Some owners opt for the full canister kit if the housing shows wear or cracking.

If you have a shop do it, labor is generally minimal — this is a straightforward job measured in under an hour at most shops — but labor rates vary significantly by region and shop type. Dealers may charge more than independent diesel specialists.

Variables That Affect Your Outcome

No two 6.7 Cummins trucks are identical in terms of service needs. Factors that shape what this job looks like for any given owner include:

• Model year — the CCV system was redesigned across generations
• Mileage and maintenance history — a truck that's never had the filter changed at 150,000 miles is a different job than one serviced on schedule
• Modifications — performance tunes, EGR deletes, and intake upgrades all affect blow-by and crankcase pressure
• How the truck is used — daily highway driving vs. heavy towing vs. low-speed fleet work
• Whether companion issues exist — worn rings, failing turbo seals, or a compromised PCV-adjacent component can make a simple filter swap feel like it didn't fix anything

The filter itself is a small, low-cost part. What it tells you about the rest of the engine depends entirely on what's happening inside your specific truck.