Engine/Exhaust - Various Noise Concerns

Model: Sedona[VQ], Amanti[GH], Sorento[BL]

Group: Engine Mechanical System(12)

Number: KT2007042402

Date: Tuesday, April 29, 2008

Area: N. America

Subject
3.8 LAMBDA Engine Noises (Engine -028- REVISED)

Description








This revised bulletin replaces information previously issued on June 1, 2007, Engine 028. It readdresses several noises on 3.8 or 3.3 litre engines used in 2006 and later Sedona (VQ) and 2007 and later Amanti (GH) and Sorento (BL). Three separate noises are covered.

Noise 1) 3.8/3.3I engines may exhibit noise for several seconds during initial start-up after sitting several hours, which typically sound like loose timing chains or excessive bearing clearance.

Noise 2) 3.8/3.3I engines may exhibit noise during or after full warm-up, which can sound like excessive valve lash (valve tap) on one or more cylinders - or - loose timing chains.

Noise 3) In fewer cases, the catalyst heat shields may produce buzzing sounds that are most noticeable after full warm-up, and under slight engine load.

This TSB will distinguish when and how to address these concerns. Please note that there have been changes to acceptable repair limits. Additionally there have been changes to the repair procedures, which are provided in the service information on KGIS.

Noise 1 - Engine Noise Only at Initial Start-up

This can be caused by oil draining back into the crankcase after sitting several hours or after sitting overnight. Since the primary tension application of the chain tensioners is oil pressure, the tensioners may initially have slack until significant oil reaches them and pressure begins to build. If the noise diminishes at the same time oil pressure builds, there is no fault with the current design timing chain tensioners. No action or repair is necessary or recommended.

NOTICE:
If necessary, this can be easily confirmed by installing an oil pressure gauge and monitoring the noise before and after oil pressure build-up.

Noise 2 - Valve Lash (Valve Tap) Type Noise - or - Excessive Timing Chain Noise





For valve tap type noise on one or more cylinders - or - for timing chain noise lasting longer then the initial 3 to 4 second start-up time, replace both LH and RH timing chain tensioners with part number 24410 3C300, unless previously done.

NOTICE:
Engine removal is no longer recommended. Please see updated service information (on KGIS) and labor op time on timing chain tensioner replacement.

Noise 3 - Catalyst Heat Shield Buzzing/Rattling Under Slight Load








NOTICE:
Check and adjust ALL heat shields on both front and rear catalysts. A good inspection measurement can be taken with a 3 mm hex wrench.





Effective Vehicle Information





Parts Information

Service Procedure





WARRANTY INFORMATION