The 2013-2018 generation is what most of you are actually driving. It’s the truck that solidified the 6.7L’s reputation as the “million-mile” engine. It predates the emissions complexity of the later trucks but still carries all the modern diesel baggage—including a closed crankcase ventilation system that, if ignored, will quietly rob you of performance and eventually leave you with a much more expensive problem.
Here’s what you actually need to know about CCV modification on this generation—not the forum hype, not the “I vented to atmosphere and now my truck smells” complaints. The real engineering, the real risks, and the real payoff.
Key components of this system:
Unlike the 2007.5-2012 trucks (which had a simpler CCV setup) and the 2019+ trucks (which use a different sensor suite), the 2013-2018 system is intelligent enough to know when you’ve tampered with it. The ECM actively monitors crankcase pressure and will set diagnostic trouble codes if the pressure deviates from expected ranges—or if it detects that the filter assembly has been removed entirely .
This matters because a “simple” vent-to-atmosphere reroute isn’t so simple on these trucks. Remove the factory CCV filter assembly and plug the intake port, and your ECM will eventually notice that crankcase pressure is reading zero (or atmospheric) and set a P1507 (Crankcase Filter Restriction) or P1508 (Crankcase Filter Restriction – Replace Filter) code .
So right away, the 2013-2018 owner faces a decision the 3rd gen guys don’t: do I work around the sensor, or do I accept that I’ll have a permanent check engine light?
Here’s what happens when you don’t change it:
1. Crankcase Pressure Builds, Seals Fail
The filter element gradually clogs with oil-soaked particulates. Flow restriction increases. Crankcase pressure rises. The ECM detects this and may set a P1507 code. If you continue driving, the pressure will eventually find an escape route—usually the path of least resistance. That’s often the valve cover gasket, oil pan gasket, front crank seal, or rear main seal .
Cost to fix: A valve cover gasket is cheap. A rear main seal on a 6.7L is not. You’re pulling the transmission.
2. Turbocharger Contamination (The Silent Killer)
As pressure builds, oil vapor is forced past the CDR valve and into the intake with greater velocity. The turbo compressor wheel acts like a centrifuge, slinging oil against the compressor housing and inlet piping. Remove your intake hose at 100,000 miles with an original CCV filter and you’ll find a puddle of oil waiting for you .
This isn’t just “messy.” Oil on compressor fins alters the aerodynamic balance of a wheel spinning at 80,000+ RPM. Efficiency drops. Spool time increases. In extreme cases, uneven oil deposits can lead to compressor wheel imbalance and bearing wear.
3. Intercooler Fouling
What doesn’t stick to the turbo eventually travels downstream. Over years of accumulated oil-soaked blow-by, your intercooler core becomes coated with an insulating layer of hydrocarbon residue. This reduces its ability to transfer heat. Intake air temperatures rise. Power drops. EGTs climb. It’s a gradual degradation you won’t notice until you drive a truck with a clean system .
4. Black Smoke and Poor Combustion
In severe cases, enough oil can be drawn into the intake that it enters the combustion chamber. This burns with the diesel fuel, producing excessive black smoke and contributing to cylinder carbon buildup .
5. Catastrophic (But Rare) Failure
The CarAraC article mentions that extreme, sustained crankcase pressure from a completely blocked filter can theoretically contribute to piston cracking . Is this common on the 2013-2018? No. Is it possible on a fleet truck with 300,000 miles and a filter that’s never been touched? Theoretically, yes. But realistically, you’ll blow a seal long before you crack a piston.
OEM and Aftermarket Options:
It’s a 10-minute job. The filter housing is on top of the valve cover, held by a few bolts. Unplug the pressure sensor, swap the element, reassemble. No tools beyond a socket set required. At $50 and 10 minutes every 50,000 miles, this is the easiest maintenance item on the truck .
So why do people reroute instead of just changing the filter?
Because changing the filter prevents overpressure events and sensor codes, but it does nothing to stop oil vapor from entering your intake.
The filter captures large oil droplets and drains them back to the sump. But it does not eliminate all vapor.
This is the distinction: Filter maintenance prevents failure. Reroute prevents contamination.
Path 1: Full Atmospheric Reroute (Vent to Air)
This is the simplest modification. You remove the factory CCV hose from the intake tube, cap the intake port, route a hose from the valve cover outlet down the frame rail, and terminate it with a small filter or simply point it downward.
Pros:
Path 2: Catch Can Installation
A catch can installs between the CCV outlet and the intake inlet. It uses baffles, mesh, or centrifugal force to condense oil vapor, collecting liquid in a reservoir while allowing “cleaned” air to continue to the intake.
Pros:
Path 3: Leave It Stock + Maintain It
Pros:
But its CCV system is a victim of its own reliability.
Because the truck runs fine with a clogged filter, owners ignore it. Because the filter is buried under a plastic cover, owners don’t know it exists. Because the truck will accumulate 200,000 miles without a catastrophic failure, owners assume “it must not matter.”
It matters. Not in the “your engine will explode at 100,001 miles” sense. In the “your turbo spools 20% slower than it did when it was new and you’ve just gotten used to it” sense.
The 2013-2018 6.7L is a million-mile engine. But only if you maintain the million-mile details. The CCV system is one of those details.
*If you’ve done a CCV reroute on your 2013-2018 6.7L, Drop your experience below.*
Here’s what you actually need to know about CCV modification on this generation—not the forum hype, not the “I vented to atmosphere and now my truck smells” complaints. The real engineering, the real risks, and the real payoff.
Part 1: The 2013-2018 CCV System – What Makes It Different
Before you decide whether to modify it, you need to understand what you’re working with. The 2013-2018 6.7L Cummins uses a closed crankcase ventilation system with active ECM monitoring. This isn’t your grandfather’s breather tube hanging under the truck .Key components of this system:
- Coalescing filter element – Captures oil mist from blow-by gases and drains it back to the crankcase via one-way check valves
- Crankcase Pressure (CP) sensor – Mounted on the valve cover, continuously monitors internal crankcase pressure
- CDR (Crankcase Differential Regulator) valve – Integrated into the filter cover, regulates the flow of gases back to the intake
- ECM integration – The computer uses pressure data to determine filter condition and can alert you when service is needed
Unlike the 2007.5-2012 trucks (which had a simpler CCV setup) and the 2019+ trucks (which use a different sensor suite), the 2013-2018 system is intelligent enough to know when you’ve tampered with it. The ECM actively monitors crankcase pressure and will set diagnostic trouble codes if the pressure deviates from expected ranges—or if it detects that the filter assembly has been removed entirely .
This matters because a “simple” vent-to-atmosphere reroute isn’t so simple on these trucks. Remove the factory CCV filter assembly and plug the intake port, and your ECM will eventually notice that crankcase pressure is reading zero (or atmospheric) and set a P1507 (Crankcase Filter Restriction) or P1508 (Crankcase Filter Restriction – Replace Filter) code .
So right away, the 2013-2018 owner faces a decision the 3rd gen guys don’t: do I work around the sensor, or do I accept that I’ll have a permanent check engine light?
Part 2: The Consequence of Neglect – What Actually Happens If You Ignore It
The factory CCV filter on the 2013-2018 6.7L has a recommended replacement interval of 67,500 to 75,000 miles, or when the overhead console displays a service reminder . Many owners ignore this. Some don’t even know the filter exists.Here’s what happens when you don’t change it:
1. Crankcase Pressure Builds, Seals Fail
The filter element gradually clogs with oil-soaked particulates. Flow restriction increases. Crankcase pressure rises. The ECM detects this and may set a P1507 code. If you continue driving, the pressure will eventually find an escape route—usually the path of least resistance. That’s often the valve cover gasket, oil pan gasket, front crank seal, or rear main seal .
Cost to fix: A valve cover gasket is cheap. A rear main seal on a 6.7L is not. You’re pulling the transmission.
2. Turbocharger Contamination (The Silent Killer)
As pressure builds, oil vapor is forced past the CDR valve and into the intake with greater velocity. The turbo compressor wheel acts like a centrifuge, slinging oil against the compressor housing and inlet piping. Remove your intake hose at 100,000 miles with an original CCV filter and you’ll find a puddle of oil waiting for you .
This isn’t just “messy.” Oil on compressor fins alters the aerodynamic balance of a wheel spinning at 80,000+ RPM. Efficiency drops. Spool time increases. In extreme cases, uneven oil deposits can lead to compressor wheel imbalance and bearing wear.
3. Intercooler Fouling
What doesn’t stick to the turbo eventually travels downstream. Over years of accumulated oil-soaked blow-by, your intercooler core becomes coated with an insulating layer of hydrocarbon residue. This reduces its ability to transfer heat. Intake air temperatures rise. Power drops. EGTs climb. It’s a gradual degradation you won’t notice until you drive a truck with a clean system .
4. Black Smoke and Poor Combustion
In severe cases, enough oil can be drawn into the intake that it enters the combustion chamber. This burns with the diesel fuel, producing excessive black smoke and contributing to cylinder carbon buildup .
5. Catastrophic (But Rare) Failure
The CarAraC article mentions that extreme, sustained crankcase pressure from a completely blocked filter can theoretically contribute to piston cracking . Is this common on the 2013-2018? No. Is it possible on a fleet truck with 300,000 miles and a filter that’s never been touched? Theoretically, yes. But realistically, you’ll blow a seal long before you crack a piston.
Part 3: The Maintenance Reality – Filters, Costs
Here’s the part that separates informed owners from everyone else: the 2013-2018 CCV filter is replaceable, serviceable, and relatively cheap.OEM and Aftermarket Options:
- The genuine OEM filter. ~$50-70. No plastic wrapping from legitimate suppliers; if it comes in shrink wrap, question its authenticity .
- Generic filters – $30-40. Mixed reviews. Some owners report identical molding marks and O-ring colors; others warn of counterfeit concerns.
- Factory recommendation: 67,500 – 75,000 miles or when the overhead message appears .
- Many experienced owners recommend 40,000-50,000 miles for trucks that idle frequently, tow heavy, or have high blow-by rates.
It’s a 10-minute job. The filter housing is on top of the valve cover, held by a few bolts. Unplug the pressure sensor, swap the element, reassemble. No tools beyond a socket set required. At $50 and 10 minutes every 50,000 miles, this is the easiest maintenance item on the truck .
So why do people reroute instead of just changing the filter?
Because changing the filter prevents overpressure events and sensor codes, but it does nothing to stop oil vapor from entering your intake.
The filter captures large oil droplets and drains them back to the sump. But it does not eliminate all vapor.
This is the distinction: Filter maintenance prevents failure. Reroute prevents contamination.
Part 4: The Three Paths – And Why the 2013-2018 Complicates Each
If you’ve decided you want cleaner intake air and are willing to accept the tradeoffs, here are your options—and the specific complications this generation introduces.Path 1: Full Atmospheric Reroute (Vent to Air)
This is the simplest modification. You remove the factory CCV hose from the intake tube, cap the intake port, route a hose from the valve cover outlet down the frame rail, and terminate it with a small filter or simply point it downward.
Pros:
- Zero oil enters your intake system
- Eliminates intercooler and turbo contamination completely
- Cheap ($30-50 for hose and fittings)
- DIY-friendly
- ECM WILL notice. The crankcase pressure sensor is still active. If you remove the factory filter assembly entirely, you’ll get P1507/P1508 codes and a check engine light .
- Odor. Multiple owners report a distinct “burnt diesel/oil” smell at idle, especially with windows down or when the vent terminates near the cab .
- Drips. In cold weather, condensation mixes with oil vapor and drips from the hose end.
- Illegal for on-road use. Venting crankcase emissions to atmosphere violates EPA regulations. Enforcement is rare, but it’s a non-compliance modification .
Path 2: Catch Can Installation
A catch can installs between the CCV outlet and the intake inlet. It uses baffles, mesh, or centrifugal force to condense oil vapor, collecting liquid in a reservoir while allowing “cleaned” air to continue to the intake.
Pros:
- Retains closed crankcase ventilation (emissions compliant)
- Reduces—but does not eliminate—oil entering the intake
- No external odor or drips
- No check engine light if you retain the factory filter housing
- Maintenance. You have to empty the can. If you forget, it becomes useless.
Path 3: Leave It Stock + Maintain It
Pros:
- Zero codes, zero legal concerns, zero warranty risk
- $50 and 10 minutes every 60,000 miles
- The system works as designed
- Your turbo and intercooler will still accumulate oil vapor over time
- You accept that “clean intake air” is a relative term
Part 5: The Decision Framework – For 2013-2018 Owners Specifically
- Stock truck, no plans to modify: Change your CCV filter every 50,000 miles with a quality element. Sleep well.
- Deleted, tuned, and/or towing heavy: Install a reroute kit that retains the factory filter housing and pressure sensor, but routes the outlet hose to atmosphere or to a properly sized catch can. This prevents codes, maintains emissions compliance (with catch can), and keeps oil out of your intake.
Part 6: The Unspoken Truth About This Generation
The 2013-2018 6.7L Cummins is the sweet spot. It has the forged internals, the stronger transmissions, and the emissions system that can be fully deleted with readily available tuning. It doesn’t have the CP4 gamble of the 2019+ trucks. It doesn’t have the 6.4L’s reputation for self-destruction.But its CCV system is a victim of its own reliability.
Because the truck runs fine with a clogged filter, owners ignore it. Because the filter is buried under a plastic cover, owners don’t know it exists. Because the truck will accumulate 200,000 miles without a catastrophic failure, owners assume “it must not matter.”
It matters. Not in the “your engine will explode at 100,001 miles” sense. In the “your turbo spools 20% slower than it did when it was new and you’ve just gotten used to it” sense.
The 2013-2018 6.7L is a million-mile engine. But only if you maintain the million-mile details. The CCV system is one of those details.
*If you’ve done a CCV reroute on your 2013-2018 6.7L, Drop your experience below.*
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