Hydraulic Valve Lifters - Noisy

9220audi01

15-89-T01
Oct 89


All
M.Y. 1988-89


Hydraulic Valve Lifters - Noisy


Cause:
Numerous starts and short trips may not allow oil to build a sufficient cushion in hydraulic lifters.


Production:
A) Check valve in oil return passage (ENGINE BLOCK)

MC Engines

As of: August 1987 (Gradual Introduction)

VIN: 44_JN007107

NF Engines

As of: May 1987 (Gradual Introduction)

VIN: 44_HN120175


B) Length of intake valves increased by 0.5 mm


3A (4 Cylinder) Engines

As of: November 1988 (Gradual Introduction)

VIN: 89_KA108480

C) Introduction of P/N 034 109 309N hydraulic lifters on 4 cylinder engines

3A (4 Cylinder) Engines

As of: August 1988

VIN: KA_000001


Service:
For severe customer complaints install hydraulic lifters with modifications - P/N 034 109 309M.

Do not replace lifters for complaints of lifter noise where vehicle has not been driven for more than one week.


Improved lifters should only be installed when lifter noise is present each time the vehicle is started.


NOTE:
Before replacement refer to repair manual for diagnostic procedures concerning hydraulic lifters.