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

Mullen Road Tests Solid-State Polymer Battery Pack

The results met or exceeded all requirements targeted for the first drive cycles for energy usage and driving range.

Mullen Automotive began Class 1 EV cargo van road testing with an integrated solid-state polymer battery pack. Vehicle road testing began on Feb. 26 at Mullen’s Commercial Tech Center in Troy, MI.

Mullen’s latest phase of solid-state polymer battery testing began in January with the installation of the battery pack into the Class 1 EV cargo van for testing system compatibility between the vehicle and pack. Recent performance testing has included on-road drive cycles as well as Dyno testing at an EPA-certified lab located in Northville, MI, Mullen said.

TEXA Releases IDC5 CAR 76.5.0 Update

IDC5 CAR 76.5.0 is characterized by over 2600 new possible selections for the major makes on the market worldwide.

TurnOnGreen, Endliss Power Team up to Expand EV Charging

TurnOnGreen said it will leverage EPI’s expertise in administering and executing power purchase agreements with commercial clients.

Autel’s ADAS Bay Max Vehicle Lift

Learn how this lift integrates mechanical repair, four-wheel alignment, and ADAS calibration, prioritizing efficiency and space utilization in your shop.

Switch EV Trainer Provides Tailored EV Tech Training

The Switch EV Trainer includes all of the components of a modern EV drivetrain on a compact, insulated, mobile platform.

Other Posts

Tool Time Podcast: SATA USA

In this all new episode of the Tool Time Podcast, Nadine and Eric sit down with Chris Springer of SATA USA.

Elywhere Launches in North America

Elywhere chargers can be configured to support power in the 1 MW range, providing solutions for electric fleets.

#3 Screwdriver “Tips”

What appears as one of the most basic tools in your box is far from it.

#2 Calipers & Micrometers

Calipers and Micrometers are essential measuring tools when exact precision is required.