Volkswagen Tech Tip: Crankcase Breather Whistling/Howling Noise

Volkswagen Tech Tip: Crankcase Breather Whistling/Howling Noise

On some 2001-’02 2.8L Passat models (ATQ engine code), a whistling/howling noise may be heard from the crankcase breather valve at idle. This problem may be caused by routing of the connection hose (rubber) between the breather valve and the intake manifold.

On some 2001-’02 2.8L Passat models (ATQ engine code), a whistling/howling noise may be heard from the crankcase breather valve at idle. This problem may be caused by routing of the connection hose (rubber) between the breather valve and the intake manifold.

Service Procedure:

  1. Remove the upper engine covers exposing the intake manifold.
  2. Locate the intake manifold changeover valve.
  3. Remove the securing plate (Fig. 1 – 3) from the intake manifold. The changeover valve (Fig. 1 – 2) does not have to be removed from the securing plate. The bolt (Fig. 1 – 1) will be discarded.
  4. Set the assembly aside (do not remove the hoses).
  5. Remove the crankcase breather valve hose. Install P/N 078 103 221 AH (new breather valve hose assembly) with new clamps, P/N N 101 662 01.
  6. Install P/N N 905 516 02, (double hex head bolt) into the intake manifold where the discarded bolt was removed (See Fig. 1 – 1).
  7. The shoulder from the double hex head bolt effectively raises the securing plate to allow clearance for the new hose assembly.
  8. Reinstall the securing plate over the double hex head bolt.
  9. Install P/N N 015 082 5, shouldered hex nut over double hex head bolt. Securing plate fastener torque = 10 Nm.
  10. Reinstall remaining parts (engine covers, etc.).

Courtesy of ALLDATA.

For additional information, visit www.alldata.com.

You May Also Like

#6 Multimeter DC Voltage Testing

Diagnosing electrical system problems isn’t always easy, and guessing is never an option.

Diagnosing electrical system problems isn't always easy, and guessing is never an option. Knowing the various techniques you can use with your digital multimeter can quickly solve most routine electrical problems.

View Full Diagram

LG Energy Solution’s Battery Facility to be Completed by 2026

LG Energy Solution said the cylindrical battery plant, called LG Energy Solution Arizona, will produce 46-Series batteries for EVs.

A Show of Changes

TechShop was on site in Orlando, FL for the Matco Tools Expo and the Mac Tools Tool Fair.

Green Li-ion Launches Lithium-Ion Battery Materials Plant

Located in Atoka, Oklahoma, it is North America’s first commercial-scale plant to produce recycled lithium-ion engineered battery materials.

Maverick Tire Changer: Handling Large Custom Wheels

Large, custom 4×4 wheels are all the rage, and Hunter’s Maverick tire changer makes handling them a breeze.

Other Posts

Introduction to the Maverick Tire Changer

Joe Keene speaks with Hunter Engineering service rep Rick Marzen on Hunter’s premium center-clamp Maverick tire changer.

U Power Launching Commercial Operation for EV Battery Swapping

Its model for two-wheeled and light four-wheeled EVs is set for a formal commercial rollout in Wuhu, Anhui Province, China.

#5 Ratchet Basics

Although there’s evidence of earlier claims, the invention of the ratchet is credited to J.J. Richardson in 1863.

Hyundai Front Windshield Camera Sensor and Blindspot Calibration

Joe Keene discusses the calibration procedure for a Hyundai Santa Cruz that needed a windshield replacement and rear bumper repair.