engine coolant AUDI A6 2000 C5 / 2.G AEB ATW Engines Valvetrain Servicing Workshop Manual
Page 34 of 51
15-60
      
Hydraulic valve lifters, checking
 
     
Special tools and equipment  
     
Feeler gauge 
     Wood or plastic wedge
     
Note:  
     Hydraulic valve lifters cannot be serviced.
     Irregular valve noise when starting engine is 
normal. 
     
-  Start engine and let run until coolant 
temperature reaches at least 80 C (176 F). 
     
-  Increase RPM to 2500 for about 2 minutes; if 
necessary test drive vehicle. 
     
Note:  
     If irregular valve noises disappear but then 
reappear during drive, replace oil retaining valve. 
Oil retaining valve is located in oil filter bracket   
Page 17
-6 . 
      If hydraulic valve lifters are still loud, locate faulty 
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