Complaint Audible "slurping" operating noise from the fuel tank Cause Conditions: • The fuel tank is...

Bulletin number

LI47.10-P-079604

Component

Fuel/propulsion system

Summary

Complaint Audible "slurping" operating noise from the fuel tank Cause Conditions: • The fuel tank is around half full • The secondary chamber is almost empty. The suction jet pump suctions up small quantities of fuel and air. This results in vibrations and turbulence, which make noises. These noises may sound like slurping. The fuel pump and the drained secondary chamber amplify certain noises which can be loud or shrill. The viscosity of the fuel and the intensity of the fuel pump also impact the noises. • The fuel level is in the area of the saddle overflow in the primary chamber. The fuel mixed with air flows back into the secondary chamber. The noises may therefore be audible for longer • If the primary chamber is no longer in the area of the saddle overflow, the noises should disappear because the secondary chamber no longer receives fuel. • The area of the saddle overflow in the primary chamber is around +/- 2 liters of fuel volume (fuel gauge shows around half full). Remedy • Refill/drain approx. 5 liters of fuel; if the noise is reduced/is no longer present due to this, the circumstance specified above is present Further measures may cause a reduction in noises in the specified area: • In isolated cases, a fuel tank installed under stress may amplify the noises. The installation position of the fuel tank and the contact surfaces on the body-in-white should be checked here. To do so, release the fuel tank and refasten it, see WIS. • Replacement of component parts such as fuel tank/delivery module does not provide a remedy! If a similar noise is heard, but the tank volume is 3/4 or 1/4 and not 1/2 as described above, another circumstance is present

Owners of these vehicles have filed 9 complaints in the fuel system category.