No Start; Cranking Speed Is Too Low

Diagnosis procedure

  • Check for correct starting procedure
    If the correct starting procedure is not used in cold weather, the cranking speed may be too low. This step is used to verify that a problem actually exists. If cranking speed is too low, all steps in this procedure must be completed.
  • Check the charging system
    A problem in the charging system can result in an undercharged battery, which will result in the cranking speed being too low. It is important to check all components in the charging system. First check the battery, then the alternator. If the battery has been replaced, make sure that the correct battery has been installed. Some VW diesels require batteries with different capacities.
  • Check the starter and connections
    Loose or corroded connections from the battery to the engine or starter will result in cranking speed that is too low even with a fully charged battery. By performing a quick voltage drop test you can detect any resistance in the starter circuit caused by bad connections or cables.
    Worn bearings, shorted windings or other internal problems can cause the starter to turn too slowly, resulting in low cranking speed. If the battery is fully charged and there is no excessive drag in the engine, the starter can be checked by performing a cranking voltage test.
  • Check the engine oil viscosity and install an engine or battery heater (optional)
    Engine oil which is too thick for existing temperature conditions will cause excessive engine drag when starting a cold engine. This is more critical as fall turns to winter because the engine may still have “summer” oil in it. A quick check of the lubrication sticker can usually verify if this condition exists.
    In some northern climates where extremely cold temperatures are experienced, it may be necessary to install an engine or battery heater, to insure that cranking speed will be sufficient to start a cold engine. This should only be done after the previous items have been checked and found to be in order.



Quality check
Suggested Repair Time — 10 time units

  • Connect engine tester VW1367 or Diesel Tachometer
  • Pull out the cold start timing advance knob.
  • Turn the ignition on, the glow plug light will come on.
  • After the glow plug light goes out, depress the clutch with the gear shift lever in neutral and crank the engine.
    -The cranking speed should be at least 150 RPM
    -The engine should start within 10 seconds.
  • Check to see that the engine:
    – Idles smoothly
    – Accelerates evenly
    – Does not smoke excessively

Note: It is normal that the engine noise is louder and that some whitish-blue smoke may be emitted from the exhaust during the warm-up period in cold weather.

If test passed:
-Return car to customer

If the cranking speed is now OK, but the car will not start, see THIS LINK