The crankcase ventilation valve is a crucial engine component typically located on the valve cover, connected to the fuel intake manifold. During the combustion process in the engine, some unburnt fuel, along with water vapor and engine oil, termed as ‘blow by gas’, gets past the pistons and enters the crankcase. The crankcase ventilation valve draws this gas mixture out of the case and redirects it into the intake manifold, allowing it to burn off completely.

Audis with turbochargers and direct fuel injection engines rely heavily on the crankcase ventilation valve, as these produce copious amounts of blow-by gas. In these modern high-performance engines, the crankcase ventilation valve is also integrated with an oil separator that separates the engine oil from the mixture, pushing the fuel and water vapor mixture into the combustion chamber, where they are entirely burned off. These valves are commonly referred to as positive crankcase ventilation valves, or PCV valves.

Consequences of Crankcase Ventilation Valve Failure

• Improper ventilation of blow-by gas causes extreme pressure in the crankcase, which can lead to leaks and force engine oil past seals and gaskets.
• Blow-by gases include unburnt and partially burnt fuel. Due to substandard ventilation, these compounds mix with engine oil and contaminate it. This degrades oil conditions by reducing its lubricating properties and accelerating the formation of sludge.
• Blow by gas, upon entering the exhaust system, causes harmful emissions as it contains toxic gases formed by partially burned fossil fuels.

Signs of Crankcase Ventilation Valve Damage in Audis

• Engine oil consumption increases as the oil intake is increased into the engine’s intake manifold. A damaged PCV valve that remains open increases the engine’s oil intake, leading to more frequent oil changes than usual.
• High pressure of blow-by gas causes oil leaks from surrounding seals and gaskets, prompting further engine issues.
• An improperly functioning PCV valve causes a vacuum leak and an incorrect air-fuel mixture, resulting in engine misfire and rough idling.
• The appearance of milky or sludgy oil residues on the dipstick or oil filter cap indicates improper ventilation, allowing moisture and contaminants to accumulate.
• Blueish smoke from the exhaust is observed due to excessive oil being burned.
• The check engine light is also triggered when an engine malfunction or performance reduction is detected due to PCV valve damage.

How to Deal with Crankcase Ventilation Valve Damage

The crankcase ventilation valve is one of the first components in Audi cars designed and installed to reduce emissions and make the emitted gases less toxic. Over the years, this valve underwent several modifications and is now prevalent as a PCV valve. Here is what our European vehicle specialists of Master Mechanics Auto Repair offer at our auto repair shop near Kalamazoo:

• Inspection and Diagnosis: Upon experiencing the malfunction signs, the PCV valve is inspected by our technician in various ways. In modern Audis, a VCDS (VAG-COM) or other compatible OBD-II scanner is used to read fault codes related to PCV system issues. In addition to this, a visual inspection of the PCV cap for cracks and leaks can also be performed to identify valve malfunctions. In cases of hard-to-find vacuum leaks, the smoke test is performed.
• Crankcase Valve Replacement: The crankcase valve, when it malfunctions, can only be replaced with a new one to restore proper vehicle functionality. The crankcase unit is disconnected from the hoses to release the vacuum buildup, and then the unit is removed. A new valve is replaced in the crankcase unit. It is advisable for the module to replace the gasket as well; however, it is not strictly necessary. The repaired unit is reassembled, and the OBD system has been reset to ensure regular vehicle operation.

Tips for a Healthy Crankcase Ventilation Valve

• Check the condition of the crankcase ventilation valve every 30,000 to 50,000 miles, during basic services for Audi. This can prevent severe damage caused by valve malfunctions.
• Inspect the crankcase ventilation valve cover between services for visible damage or cracks.
• Use high-quality Audi-specified oil and OEM oil filters during factory-scheduled oil and filter changes.
• Try to avoid extended idling and make short trips instead. There, the engine fails to reach its optimal temperature, leading to accelerated sludge formation.

Fix Your Audi’s Crankcase Ventilation Valve Malfunction in Kalamazoo’s Premium European Auto Repair Shop

At Master Mechanics Auto Repair, we’re proud to provide repairs for Audi crankcase ventilation valve damage using dealership-quality OEM parts, skilled technicians’ labor, and exceptional customer service at a considerably lower expense. We staff ASE-certified technicians who have been exclusively working with European auto models for decades, alongside technicians specializing in other imported and domestic brands. Operating from Kalamazoo, we also assist auto owners of surrounding cities such as Battle Creek and Portage. With over 40 years of experience, we have established ourselves as the premier auto repair shop for European, domestic, and other imported vehicle models in Kalamazoo.