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josefer · 07-29-2012, 08:59 AM

Have had a 2002 S 3.2. At around 20,000 kms. in odometer subtle knocking noise began at wall behind seats, while particularly going over cobble-paved roads after a 10 or 15 minute warm-up. At times it also looked as coming from doors, or seat belts, or engine, or...

Turned out to be faulty rear suspension trailing arms (parts no. 986-331-143-4 or 043-7). The ball-joint cap looses with time and as grease inside gets hot and thin, ball-joint knocks and transmit noise to the wall where they're attached. More easily reproduced when lifting accelerator pedal, going slow. Can be first at right or left side, but with time problem goes to both.

Lots of chassis hearing tests before finding it. Hope this helps.

07-29-2012, 08:59 AM	#1
josefer Registered User Join Date: Jul 2012 Location: Puerto Vallarta Posts: 4	Knock noise from behind rear wall Have had a 2002 S 3.2. At around 20,000 kms. in odometer subtle knocking noise began at wall behind seats, while particularly going over cobble-paved roads after a 10 or 15 minute warm-up. At times it also looked as coming from doors, or seat belts, or engine, or... Turned out to be faulty rear suspension trailing arms (parts no. 986-331-143-4 or 043-7). The ball-joint cap looses with time and as grease inside gets hot and thin, ball-joint knocks and transmit noise to the wall where they're attached. More easily reproduced when lifting accelerator pedal, going slow. Can be first at right or left side, but with time problem goes to both. Lots of chassis hearing tests before finding it. Hope this helps.