16 11 130 Checking Tank Cap Pressure Relief Valve

WARNING: This page is about a different car, the 2008 BMW Alpina and 2007 BMW Alpina. However, it is still accessible from the selected car via links, so may be relevant.

Special tools required:

13 3 010
16 1 171
16 1 172
16 1 173

Necessary preliminary tasks:

Remove tank cap

Turn pressure regulator on special tool 16 1 171 counterclockwise up to stop.

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

Connect pressure sensor (2) of Diagnosis and Information System with a measuring range of 0...25 bar.

Fig 1: Identifying Air Line, Pressure Sensor, Fast-Release Coupling And Special Tool (16 1 171)

Courtesy of BMW OF NORTH AMERICA, INC.

Select special tool 16 1 172 or 16 1 173 matching vehicle's filler cap and attach to quick release coupling of special tool 16 1 171 .

Install tank cap on selected special tool.

Fig 2: Identifying Special Tools (16 1 172) And (16 1 173)

Courtesy of BMW OF NORTH AMERICA, INC.

Check testing equipment for leaks!

Select "Measurement" function on Diagnosis and Information System (DIS).

Increase pressure by 0.2 bar with pressure regulator on special tool 16 1 171 .

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

Allow a rest period of approx. 20 secs.

Read off and note down starting pressure.

Wait approx. 120 secs.

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

Fig 3: Identifying Supply Line And Special Tools (13 3 010) And (16 1 171)

Courtesy of BMW OF NORTH AMERICA, INC.

Measurement evaluation:

Pressure drop up to 0.01 bar:
System OK
Pressure drop over 0.02 bar:
System leaking beyond permitted levels

If system is leaking, check connection points for leaks.

Check tank cap pressure relief valve.

Follow same test procedure as for "Checking testing equipment for leaks".

Increase pressure by 0.3 bar with pressure regulator on special tool 16 1 171 .

Measurement evaluation:

Pressure drop up to 0.01 bar:
Tank cap pressure relief valve OK
Pressure drop over 0.02 bar:
Tank cap is leaking and must be replaced