Idle Speed

WARNING: This page does not describe the selected car, but rather 13 other vehicles, including the 1999 BMW Z3, 1999 BMW M3, 1999 BMW M Roadster, 1999 BMW M Coupe, and 1999 BMW 740iL. However, it is still accessible from the selected car via links, so may be relevant.

Idle speed is controlled by an idle speed control valve. Ensure engine is at normal operating temperature, valve clearance is correct and all electrical accessories are off.

Connect dwell/tachometer to engine. Ensure idle speed is within specification. See IDLE SPEED & CO LEVEL table. If idle speed and CO level are not within specification, check idle speed control valve or intake manifold for air leaks.

IDLE SPEED & CO LEVEL

Application⁽¹⁾

Idle RPM

CO Level %

4-Cylinder

810-890

.5-.7

6-Cylinder

660-740

.2-1.2

750-850

.2-1.2

⁽¹⁾	Specification for M5 is not available from manufacturer.