If you drive a diesel truck or a modern turbocharged car, you've probably heard the term " CCV" mentioned in maintenance discussions. The CCV system is a crucial yet often overlooked part of engine health and emissions control. In this guide, we'll detail what the CCV is , how it works, its core components, the role of the CCV filter, and important maintenance considerations every vehicle owner should know.
What Does CCV Mean?
CCV stands for Closed Crankcase Ventilation, often abbreviated to "crankcase ventilation." This system is designed to control "blow-by" gases and oil vapors that escape from the combustion chamber into the crankcase.
In any internal combustion engine, a small amount of combustion gases leak past the piston rings into the crankcase. This "blow-by" gas can carry oil mist and unburned fuel vapors. Without a ventilation system, crankcase pressure builds, resulting in sludge, leaks, and excessive emissions. The CCV system filters these gases and returns them to the engine intake, reducing harmful emissions and preventing oil buildup in critical components.
What Is a CCV System?
A typical CCV system is simple but effective, consisting of three core components:
- CCV valve : Regulates crankcase pressure, preventing overpressure or vacuum.
- Hose: Directs blowby gases from the crankcase to a filter/separator and then back to the intake.
- Separator/filter : Captures oil mist before the steam re-enters the combustion cycle.
How a CCV system works
Here's the step-by-step process:
- Blowby gases and oil mist accumulate in the crankcase.
- The CCV valve opens to release the mixture.
- The steam flows through the hose to the separator/filter, which captures the oil droplets (which then flow back to the oil sump).
- The clean steam is then sent to the intake manifold and burned during the combustion process, eliminating waste and reducing emissions.
What Is a CCV Filter?
The CCV filter (also known as the oil-gas separator) is the heart of the CCV system. Located in the CCV hose line, it acts as a barrier, capturing and coalescing oil droplets from the blowby gas into larger droplets before returning the purified gas to the intake.
The CCV filter's functions include:
- Maintaining a clean intake tract
- Reducing oil contamination in the turbocharger and intercooler
- Stable crankcase pressure
- Minimizing fuel consumption and emissions
Because it is a consumable part, the CCV filter needs to be inspected and replaced regularly. You can usually do this at the intervals recommended in your owner's manual.
CCV vs. PCV: What's the Difference?
While both CCV and PCV systems manage crankcase gases, they operate differently. Here's a comparison:
| Feature | PCV (Positive Crankcase Ventilation) | CCV (Closed Crankcase Ventilation) |
|---|---|---|
| Common Use | Gasoline engines | Diesel/turbocharged engines |
| Method | Uses intake vacuum | Sealed, filtered path |
| Oil Separator | Limited | Includes oil separator/filter |
Signs of a CCV System or Filter Failure
Ignoring a CCV system failure can result in expensive repairs and even damage to the turbocharger. The CCV system should be inspected at every oil change, and watch for the following warning signs:
- Oil leaks: These are often found in the oil pan, valve cover, or around the crankshaft seal.
- Poor engine performance : Power loss due to oil contamination of the intake air.
- Increased emissions : Visible smoke coming from the exhaust or a failed emissions test.
- Oil in the air intake : Check the intake manifold or intercooler; if oil residue is visible, the CCV filter may be clogged.
- Unusual odor : A strong fuel or oil odor emanates from the engine compartment due to escaping unfiltered vapors.
What Is CCV Delete?
"CCV delete" is a modification that bypasses the factory CCV system. Instead of recirculating steam back to the intake, it vents directly to the atmosphere.
Advantages
- Cleaner intake system : No oil mist contaminates the intake, turbocharger, or intercooler, resulting in less carbon deposits and potential component damage.
- Reduced filter maintenance costs : No need to replace the factory CCV filter.
Disadvantages
- Emissions noncompliance : Removing the CCV is not street legal in most areas.
- Warranty and inspection risks : If detected, CCV removal could void the engine warranty and cause emissions testing failure.
- Environmental hazards : Unfiltered blowby releases hydrocarbons and particulate matter, contributing to air pollution.
Should You Remove Your CCV?
For street-legal vehicles, removal is strongly discouraged. The risks of fines, failed inspections, and lost warranty far outweigh any short-term benefits.
For off-road or racing applications (where permitted), removal or rerouting may be considered, but be sure to check local regulations first.
In addition to CCV removal, there's also a method called CCV rerouting. This approach doesn't completely remove the engine, but rather redirects the steam outside the engine compartment or into a separate separation device. This method can reduce the risk of emissions violations to a certain extent, making it an alternative option for many car owners.
Conclusion
The CCV system is far more than just a "widget"; it's a guardian of engine health and a key factor in meeting emissions standards. To get the most out of your CCV system, it's recommended to follow maintenance intervals to replace the CCV filter and regularly inspect it for signs of malfunction.
FAQs about CCV
Are all cars equipped with a CCV system?
No. Most older or naturally aspirated gasoline engines use a PCV system. Diesel engines and modern turbocharged gasoline engines are typically equipped with a CCV system.
What does CCV stand for in a car?
In cars, CCV means Closed Crankcase Ventilation, which filters crankcase vapors and directs them back into the intake.
What does a CCV filter do on a diesel engine like a 6.7 Cummins or 6.7 Power Stroke?
The CCV filter on a diesel truck removes oil mist from blowby gases before they enter the turbocharger and intercooler.
How often should I change my CCV filter?
Please check your owner's manual. Many 6.7L Cummins trucks recommend changing it around 67,500 miles, while some 6.7L Power Stroke engines require replacement between 30,000 and 45,000 miles.
Is it a good idea to remove the CCV?
For street-driving vehicles, this isn't true. However, for racing or off-roading, it is.
What's the difference between gasoline and diesel CCV systems?
The CCV system on a diesel engine is designed for higher blowby volumes and uses a CCV filter that's easier to maintain. A gasoline engine's CCV system is smaller and may require a simpler oil separator because gasoline engines produce less blowby than diesel engines.
