VW TDI PD camshaft repair
I did a camshaft and lifter replacement on a PD TDI last week. The PD engines have a characteristic tendency towards premature valvetrain wear, due to flaws in design and materials. At ~88k miles, this car was in the early stages of camshaft failure. This was a preemptive replacement of camshaft, lifters, and cam bearings with updated parts before the problem got bad enough to affect the car’s driveability or damage other engine components.
The patient: a 2004 Jetta Wagon, engine code BEW.
Mostly disassembled. Valvetrain must be taken apart one-half crank revolution *before* (or after) #1 TDC so that the tandem pump drive slot in the back of the cam is vertical, allowing the cam to be lifted out without removing the tandem pump.
Parts removed from engine.
Closer view. Not pictured is the cam, which had significant wear on the exhaust lobes of #2 and #4 cylinders, with corresponding wear patterns evident on the surfaces of those lifters. The lower cam bearings were also worn to a severe degree, as is characteristic of the PD design.
Head with new reversed lower cam bearing shells and updated black nitrided-finish lifters installed.
Cam bearing caps with modified upper bearing shells installed for improved oil flow.
New cam lubed for installation and set into place. The valve lobes on the PD cam are unusually skinny to make room for the wide injector lobes. The thin valve lobes and resulting high psi forces between the lobes and lifters are a main factor in the PD design’s problems with premature cam and lifter wear.
Cam torqued down w/new hardware, timing gear and belt installed, engine set back to TDC and timed.
Injector rockers installed and injector lash adjusted.
Cam torsion set, buttoned up and running smooth.