What a CCV Reroute Actually Does
A CCV reroute kit changes where crankcase vapor goes. The factory system routes that vapor back into the intake, where it is burned with the intake charge. A reroute sends it somewhere else instead: into a catch can that separates the oil from the vapor, or out through a vent line.
Those two setups are not the same thing. A closed-loop catch can returns the separated air to the intake. A vent line discharges to the atmosphere, which brings cold-weather and legal problems covered later in this guide. If you already know your platform, the CCV reroute kits collection lists current options for Powerstroke, Cummins and Duramax trucks.
Symptom Checklist: Do You Need One?
- Oil visible in the intercooler piping or intake tubing when you pull a boot off
- Oily residue building up on the turbo inlet or compressor wheel
- A CCV filter that needs replacing more often than the interval feels reasonable
- Noticeably more oil consumption than the truck showed when it was newer
- A front or rear main seal weeping on a truck with no other reason to leak
- Silicone intercooler boots that feel slick, swollen or soft
If two or more of these sound familiar, a reroute kit is worth looking at. If none of them do, your factory system may still be working as designed and there is no reason to change it yet.
How the Factory CCV System Works
Crankcase pressure and where the vapor goes. As the engine runs, blow-by gas leaks past the piston rings and builds pressure in the crankcase. The factory CCV system vents that pressure by routing the vapor back into the intake tract. This closed-loop design is standard emissions practice on modern diesel platforms.
Why oil ends up in the intake. Crankcase vapor does not travel alone. It carries fine oil mist, and the separator or filter in that path can only catch so much before it saturates. Once it does, oil reaches the intake tract, the intercooler piping and the turbo inlet.
What that oil does. An oil film on the intercooler core works against cooling. Hot oil also softens silicone boots over time, and a soft boot can blow off its pipe under heavy towing boost.
Check Blow-By Before You Buy
A reroute treats a ventilation restriction. It does not repair an engine that is making too much blow-by. Worn piston rings, a leaking turbo seal or injector problems can all push more gas into the crankcase than any ventilation system can handle.
Shops measure crankcase pressure with a digital manometer, which reads in inches of water column. A standard boost gauge reads in PSI and cannot show the small pressure changes that matter here. If the reading stays low at idle but climbs under load, a restricted separator is a likely cause. If it is high even with an open vent path, the problem is inside the engine, and a reroute will not fix it.
Symptoms of a Restricted or Failing CCV
Oil film in the intake tract and intercooler. This is the symptom most owners notice first, usually when a boot comes off for another job and the inside is coated in residue that was not there a year earlier.
Seal and gasket leaks. Excess crankcase pressure has to go somewhere. A front or rear main seal that starts weeping, or an oil pan seam that begins to seep, is worth checking against crankcase pressure before you assume the part is simply worn.
Reroute vs Filter Replacement
Cost over ownership. Replacing the factory CCV filter on schedule is the cheaper choice in any single instance, but it is a recurring cost, and it does not stop oil from reaching the intake between service intervals. A reroute kit costs more once and removes the filter expense on platforms that have one. For owners planning to keep a truck long term, that can come out ahead on total cost.
If you are also planning exhaust or EGR work on a truck used off-road or in competition where permitted, browse the diesel delete kits collection next to your CCV kit before you order either one separately. Read the compliance section below first.
What's in a Reroute Kit
Hose, fittings and separator. A standard kit includes high-temperature hose rated for crankcase vapor and heat cycling, the fittings that connect to the existing crankcase port, and in most kits a separator stage that pulls oil out of the vapor stream.
Catch-can options. Some kits send vapor to a catch can, which gives you a reservoir you drain on a schedule. That is more maintenance, but it usually keeps oil out of the intake better than passive separation alone. Not sure which setup suits your truck? This catch can vs CCV reroute breakdown compares the two side by side.
Platform Fitment
Powerstroke. Fitment differs across the 6.0, 6.4 and 6.7 Powerstroke generations, and a kit built for one will not bolt to another without modification. Confirm your exact engine and model year before ordering from the Powerstroke CCV reroute kit lineup.
Important for 2011 and later 6.7L trucks: the factory system monitors the ventilation circuit, and a reroute can set code P04DB. A tuner may be required to clear it. Read the P04DB diagnosis guide and the tuner notes on the product page before you buy.
Cummins. The 6.7 Cummins is the platform most commonly fitted with a CCV reroute, and kits are matched to that generation's crankcase port location and hose routing. Check the Cummins CCV reroute kit collection to match yours.
Duramax (LLY, LBZ, LMM). These three generations, covering 2004.5 to 2010 trucks, share one crankcase ventilation layout. EngineGo lists a single CCV/PCV reroute kit for the 2004 to 2010 LLY, LBZ and LMM, so you do not need a separate kit per generation. GM calls this system PCV, and many Duramax kits use "PCV reroute" in the name. Important: this kit is not listed for the LB7, LML or L5P. If you own one of those, check fitment before ordering, and the Duramax CCV reroute by engine guide covers how to identify each engine.
Install Difficulty and Routing Mistakes
A CCV reroute is one of the more approachable diesel upgrades. Most installs run one to two hours with basic hand tools, since the job is mostly hose routing and fitting connections. Clearance around the crankcase port is the main variable between platforms. Routing is where installs go wrong.
- Avoid sags and low points. Crankcase pressure is low, and it cannot push a slug of oil or water uphill. A dip in the hose collects liquid and blocks the vent. Run the hose with a continuous downward slope and secure it so vibration does not create sags later.
- Use the hose size the kit specifies. An undersized or kinked line restricts the vent and defeats the purpose of the kit.
- Plan for cold weather if the kit vents out a line. Blow-by carries water vapor. In freezing temperatures it can condense in the hose and freeze at the exit overnight. A blocked vent lets crankcase pressure build fast on the next start, and a rear main seal can fail. A closed-loop catch can setup avoids this problem.
- Use proper safety gear. Let the engine cool, support the truck on jack stands and wear eye protection.
Compliance and Warranty Notes
Crankcase ventilation is part of a diesel truck's emissions system. Federal rules do not allow a road-certified diesel to discharge crankcase vapor directly into the atmosphere, and an open vent line on a truck used on public roads can create legal exposure for the owner and the installer. Some products are intended only for off-road, race, or non-public-road use where permitted. A disclaimer on a product page does not change how a vehicle was certified. Check federal, state and local laws before purchase and installation, and note that California and other states apply their own rules to aftermarket parts. The customer is responsible for legal compliance.
Warranty works on a claim-by-claim basis. Under the Magnuson-Moss Warranty Act, a manufacturer generally cannot void an entire warranty because an aftermarket part is present, but it can deny a claim if it shows that the part caused or contributed to the failure. A blown seal from a frozen or sagging vent line would be an easy claim to deny. Check your warranty terms before you modify a truck still under factory coverage.
FAQs
Do I need a CCV reroute if my truck is not burning much oil?
Not necessarily. If you see no oil in the intake tract or intercooler piping and consumption is normal for the mileage, the factory system may still be handling vapor well. The symptom checklist is a better indicator than oil consumption alone.
Is a catch can better than a straight reroute?
A catch can needs periodic draining, but it usually keeps oil out of the intake better than a passive separator and avoids the cold-weather freezing risk of an open vent. A straight reroute is lower maintenance but relies on its separator stage and on correct hose routing.
Will a CCV reroute set a code?
It can. On 2011 and later 6.7L Powerstroke trucks, the factory system monitors the ventilation circuit, so P04DB is a known risk. A tuner may be required. Check the product page for tuning notes.
Is a CCV reroute legal on a daily driver?
Do not assume it is. Open venting on a road-certified diesel is a federal emissions issue, and some kits are for off-road or race use only where permitted. Confirm your local rules before buying.
