Hydraulic Adjusting Elements, Checking: Procedure

-- Start the engine and let it run until the coolant temperature is at least 80 °C (176 °F).

-- Increase engine speed for about 2 minutes to approximately 2500 RPM, perform road test if necessary.

NOTE:

If the irregular valve noises disappear but always appear when driving short differences, replace the oil check valve -arrow- on the rear face side in the affected cylinder head.

Fig 1: Identifying Oil Check Valve

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

If the hydraulic valve lifters are still noisy, determine which lifter is defective as follows:

-- Install the left or right cylinder head cover. Refer to CYLINDER HEAD COVER, REMOVING AND INSTALLING .

-- Rotate the crankshaft until the cams on the hydraulic adjuster to be checked are at the top. To do this:

• Vehicles with a manual transmission: shift into 4th gear, turn off the ignition and push the vehicle forward.
• Vehicles with an automatic transmission: Remove the noise insulation and rotate the crankshaft clockwise by the vibration damper central bolt.

-- Determine the play between the cams and the roller rocker lever.

Fig 2: Identifying Play Between Cams With Screwdriver -Arrow- And 0.20 mm Feeler Gauge

Courtesy of VOLKSWAGEN GROUP OF AMERICA, INC.

-- Press the roller rocker lever down with a screwdriver in direction of -arrow-.

If a 0.20 mm feeler gauge can be inserted between camshaft and roller rocker lever:

-- Replace the hydraulic adjuster.