For 1990-2009 cars only
There are four steps to diagnosing engine noise. You must determine the following:
| • | The type of noise. |
| For example, is the noise a light rattle/tapping or a low rumble/knocking? |
| • | The exact operating condition under which the noise exists. |
| Note factors such as the ambient temperature, the amount of engine warm-up time, the engine temperature, engine RPM's, and other specifics. |
| • | At what rate the noise occurs, and at what location in the engine. |
| Remember, engine noises are generally synchronized to either engine speed (crankshaft, flywheel, connecting rods, balancer, or pistons and related components) or one-half engine speed (valve train noise such as rocker arms, valve lifters, and timing chain). Try to determine the rate at which the noise is occurring. |
| • | Compare the engine sounds to other engines and make sure you are not trying to correct a normal condition. |
