I've got some excessive valvetrain noise from my M103 as well but I'm suspecting that a previous owner abused the car a bit (though its really clean in and out), I am paying close attention to this thread....timing chain check is in store for my car.

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TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth