Engine Controls - Rough Idle
SOURCE: Hyundai Tech Net Times Volume 14 Issue 3 2004TITLE: Diagnosing a Rough Idle
APPLIES TO: 2004 Sonata
SERVICE TIP:
If a 2004 Sonata equipped with the 2.4L engine occasionally displays intermittent rough idle and driveability conditions, the Check Engine Light may or may not be lighted. If the EGR Solenoid (P/N 39460- 38750) sticks closed intermittently at idle. Initial bench testing may not reveal this condition. The intermittency may occur only when the part has warmed up from being energized and the engine compartment temperature. Therefore, test the part only on the vehicle after a test drive to warm it up. Test by disconnecting the EGR hose when the vehicle exhibits rough idle symptoms. If the rough idle goes away, replace the EGR solenoid.