16 00 100 Checking fuel tank and tank ventilation system for leaks

WARNING: This page does not describe the selected car, but rather 16 other vehicles, including the 2006 BMW 330Ci, 2005 BMW 330xi, 2005 BMW 330i, 2005 BMW 330Ci, and 2004 BMW 330xi. However, it is still accessible from the selected car via links, so may be relevant.

Special tools required:

13 3 010
16 1 157
16 1 171
16 1 174

NOTE: The following procedure is only applicable to vehicles without the tank leak diagnosis module (DM-TL).
Vehicles with carbon canister only
A leak test must be carried out if a leak is suspected in the tank ventilation system.
Vehicles with leak diagnosis pumps (LDP)
If a leak in the tank ventilation system is indicated by the "Check engine" indicator lamp in the instrument cluster lighting up, a leak test must be carried out.
Read out the fault memory of the DME control unit and carry out a diagnosis. If the sensors are OK, then begin the leak test.

The following conditions must be observed to obtain plausible measuring results:

Contents of fuel tank 50 % +/- 25 %
Park the car in the workshop at least 2 hours before the test so that the fuel temperature is approximately that of the workshop temperature (ideal fuel temperature approx. 10...20°C).
Never refuel the vehicle directly prior to the leak test due to the strong emission of gas by the fresh fuel.

Release screws (1/3), remove panel (2).

Remove expansion rivet (4), remove panel (5).

Fig 1: Removing Panel

G03123765

Courtesy of BMW OF NORTH AMERICA, INC.

Applicable to vehicles with leak diagnosis pumps (LDP) only.

Unlock line (3) and detach from dust filter.

Seal dust filter with special tool 16 1 157.

Fig 2: Unlocking Line And Detach From Dust Filter

G03123766

Courtesy of BMW OF NORTH AMERICA, INC.

Applicable to vehicles only equipped with a carbon canister only.

Release lock of line (1), detach line from carbon canister (5).

Seal opening on carbon canister with special tool 16 1 157.

Fig 3: Releasing Lock Of Line

G03123767

Courtesy of BMW OF NORTH AMERICA, INC.

Remove tank cap and connect special tool 16 1 174 to tank filler neck.

Using adjusting wheel (1), clamp special tool 16 1 174 firmly to tank filler neck.

Fig 4: Clamping Special Tool Firmly To Tank Filler Neck

G03123768

Courtesy of BMW OF NORTH AMERICA, INC.

CAUTION: Set pressure regulator on special tool 16 1 171 fully in "-" direction.

Connect special tool 16 1 171 using compressed air line (1) to garage compressed air system (8...10 bar).

Connect pressure sensor (2) of Diagnosis and Information System with measuring range of 0...3.5 bar.

Fig 5: Connecting Special Tool Using Compressed Air Line To Garage Compressed Air System

G03123769

Courtesy of BMW OF NORTH AMERICA, INC.

CAUTION: Do not connect fast-release coupling (3) of special tool 16 1 171 yet.
Select "Measurement" function on Diagnosis and Information System (DIS).
Set measuring range in accordance with pressure sensor to 0-3.5 bar.
Using pressure regulator on special tool 16 1 171, increase pressure by 0.050 bar.
Connect special tool 16 1 174 to fast-release coupling of special tool 16 1 171.
Using pressure regulator on special tool 16 1 171, reset gauge pressure in fuel tank to 0.050 bar.

CAUTION: Do not under any circumstances increase pressure by more than 0.100 bar as this would result in damage to the fuel tank and venting system.

Using special tool 13 3 010, disconnect supply line from special tool 16 1 171 to tank filler neck.

Allow a rest period of approx. 20 secs.

Read off and note down starting pressure value, then wait 60 secs.

Read off final pressure value and compare with starting pressure value.

Measurement evaluation:

MEASUREMENT EVALUATION

Pressure drop between 0.008 and 0.010 bar.	Measure again.
Pressure drop in 60 secs. greater than 0.010 bar.	System leaking beyond permitted levels. Carry out leak test.16 00 510 Conducting leak test on fuel tank and tank ventilation system