Another important point to remember not covered above. This quirky dip-stick has an O-ring that seals the tube and acts like a piston as it is pushed in. The clever Germans realized this and drilled a 1mm hole about an inch below the top of the tube to vent air space between oil and O-ring. If this hole is blocked with dirt as it usually is:
1) The oil level is pushed down in the tube as the dip-stick is pushed in giving false low reading.
2) If oil is checked in the morning after a hot engine has stood overnight oil is sucked up in the tube as air cools giving false high reading.
Answer? - Throw away the O-ring!
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