For 1990-2009 cars only
There are four steps to diagnosing engine noise. You must determine the following conditions:
| • | Type of noise. |
| • | Determine the exact operating condition under which the noise exists. |
| • | At what rate, and at what location in the engine. |
| • | Compare sounds in other engines to make sure you are not trying to correct a normal condition. |
Identify the type of noise. For example, a light rattle or low rumble.
Remember, engine noises are generally synchronized to either engine speed (caused by the crankshaft, connecting rods or pistons) or one-half engine speed (valve train noise). Try to determine the rate at which the noise is occurring.
