VARIATIONS

Engine wear is both good and bad, unavoidable and avoidable. It is good initially only because it helps parts fit together perfectly when new. Later on, it is bad because it causes parts to fail or function improperly. It is unavoidable because no part lasts forever. However, it is avoidable to a degree because by eliminating unnecessary wear, the life of your engine, and therefore your car, can be extended.

Engine wear occurs in three phases. In the initial stage, a short wear-in period causes new parts to mesh correctly. The second, much longer, period coincides with the useful life of the part. The third and final phase is rapid wear and part failure. It is desirable to minimize wear from the first stage, prolong the length of the second stage and therefore delay the inevitable third stage.

Engine wear is caused by basically four situations: corrosion, abrasion, friction, and rust. Let's look into each situation a little more:

• Corrosion
• Abrasion
• Friction
• Rust

SYSTEMS
ENGINE WEAR
READING THE SPARK PLUGS
CORROSION