This is quite a job, needless if your engine is quiet (no ticking sound when idling hot). If regular oil changes were a part of the history on an engine they should not need replacing. To get to them you remove the cam cover then the timing gear/chain is removed the cam comes out by loosening the bolts in a very specific sequence only then can you pull the cam followers .... its probably a good idea to replace the timing chain while its off unless its been replaced before . . . more $$$$

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!