Engine Timing

From BMW E34 Encyclopedia

The primary symptom of timing that is out of specification is a blown engine. Do not accept work and tow the car back to the shop if your engine refuses to hold the idle after a rebuild.

Symptoms[edit]

  • Engine is running rough
  • Random O2, lean, or rich condition codes are thrown
  • Slow engine response when switching gears

Diagnostic[edit]

  • Start the car, and lean against the car's fender while the engine is shaking. If your whole body is shaking this is an indication of a non-mount related vibration.
  • Connect a vacuum gauge to PCV plate in the rear or brake booster line. If the reading is steady but below 14-16 Hg, your timing is most likely low and is out of specification.

Repair[edit]

The repair is straightforward but requires two sets of hands and a special BMW toolkit. The toolkit allows you to lock the flywheel in place, aligns the camshaft, and keeps the chain tensioner in place.

  • Follow the torque specifications to a tee
  • When spinning the engine, always spin it to the right while facing the front of the car
  • Do not forget to remove the flywheel locking pin when attempting to spin the engine, or before starting the car


Consult the Bentley repair manual for a detailed break down of this job