034Motorsport Reinforced Silicone Crankcase Breather Hose for Audi A4, A4 Quattro, and Volkswagen Passat (1997–2003)

Built from fully reinforced silicone, the 034Motorsport Crankcase Breather Hose replaces the factory rubber breather hose on Audi A4, A4 Quattro, and Volkswagen Passat models. The factory rubber part tends to crumble and leak. A crankcase breather hose belongs to the positive crankcase ventilation system, which routes crankcase pressure and oil vapor back into the intake to be burned. This hose runs from the bottom of the intake manifold to the check valve on the lower block breather hose. Heat, oil vapor, and pressure make it a common failure point. A split or cracked hose lets in unmetered air and can cause boost leaks. It can also trigger a check engine light for an intake air leak or another airflow fault, and a severe leak can bring rough running and misfires.

034Motorsport parts sold by PMB Performance carry a 24-month warranty.

This hose replaces the factory rubber hose sold under OE number 058103221E. It comes in black only, and hose clamps are included, so it goes in as a complete replacement. Look for oil residue on the hose, the engine block, and nearby parts, since escaping crankcase vapor leaves them soiled with oil and moisture. A burnt oil smell is another warning sign. 034Motorsport makes the hose in the United States. The company was founded by Javad Shadzi in 2005, and it designs, tests, and builds its parts at its own facility in Fremont, California.

Technical Details

• Manufacturer: 034Motorsport
• Part number: 034-101-3024
• Part name: engine crankcase breather hose
• Material: fully reinforced automotive silicone
• Routing: bottom of the intake manifold to the check valve on the lower block breather hose
• Replaces OE number 058103221E
• Color: black only
• Includes hose clamps
• Made in the United States
• Warranty: 24 months

Common Questions

Are hose clamps included?
Yes. The clamps come with the hose.

How do I know my breather hose has failed?
Look for cracks, splits, or oil residue around the hose. A check engine light for an intake air leak, or a misfire, can also point to a leaking breather hose.

Is it available in other colors?
No. 034Motorsport offers this hose in black only.

PMB carries this hose for owners chasing vacuum and boost leaks on these cars.

Fitment & Compatibility

Check the fitment table below to confirm your model and year. If you are unsure, PMB can verify the fit from your VIN.