A tapping sound in the engine compartment may be heard after engine warm-up on 2007-2008 Dodge Nitro vehicles. This bulletin involves the installation of a serpentine drive belt and a new design idler pulley using a revised belt routing.
This bulletin applies to models equipped with the 4.0L engine.
- Start the engine and allow to idle for 5 minutes to bring accessory drive components to operating temperature.
- Set HVAC to windshield defrost mode. Set temperature to the coldest setting, and turn on the A/C. While maintaining an engine speed of between 1800 – 2000 rpm, listen for a tapping sound. If tapping is evident, shut the engine off. Remove the serpentine drive belt. Do not let the tensioner arm snap back to the free position, as this may damage the tensioner.
- Restart the engine and listen for the tapping sound. If the tapping sound remains, proceed with further diagnostics. If the sound is gone, install the new idler pulley and serpentine drive belt using the revised routing.
Serpentine drive belt……….53013864AB
Serpentine drive idler………53013927AA
Authorized modification label…04275086AB
The new replacement idler pulley replaces position #1 shown here (upper idler pulley). Note the revised drive belt routing. 1) Upper idler pulley; 2) Driver side idler pulley; 3) Passenger side idler pulley.