Engine - Rattle, Buzz On Cold Start Or Low RPM Acceleration

GROUP
ENGINE

NUMBER
12-EM-007

DATE
NOVEMBER 2012

MODEL(S)
MULTIPLE

SUBJECT:
RATTLE / BUZZING SOUND DURING INITIAL COLD START OR
WHEN ACCELERATING FROM LOW ENGINE RPM

This bulletin supersedes TSB 10-EM-005 to include updated Applicable Vehicles listing.

Description:
Some drivers of the affected vehicles (listed below) equipped with the 2.0L Turbocharger engine may notice a slight engine rattle or buzzing sound during certain operating conditions. The sound may sound similar to a loose exhaust heat shield.

This sound may be noticed:
^ When the engine is started after a long cool down period with coolant temperature less than 86°F (30°C). Initial start up rattle/buzzing may last for 25 seconds or longer.
^ During acceleration with engine speed between 1,500 ~ 2,500 RPM.

Applicable Vehicles:
^ 2011 MY and later (YF) Sonata 2.0L Turbo
^ 2013 MY and later (BK) Genesis Coupe 2.0L Turbo
^ 2013 MY and later (AN) Santa Fe Sport 2.0L Turbo

Additional Information:





During normal engine operation, natural engine vibrations are transmitted to the turbocharger waste gate actuator rod, the pivot point, and the waste gate valve. The rattle or buzzing sound that may occur results from the required tolerances in the waste gate pivot point and the waste gate valve.

These tolerances are necessary to allow operation under the extreme operating temperatures experienced by the turbocharger.

Service Action:
No repair should be attempted for this rattling or buzzing condition. This normal operating characteristic will not affect the performance or durability of the vehicle.