Cylinder Compression, Checking - BMW 5251 Service Manual

113-5
Cylinder Head Removal and Installation
I
<
Fuel line plugs
(Tool No. BMW 13 5 281113 5 282)
4
Fuel line removal tool for quick-disconnect fittings
(Tool No. BMW 16 1 050)
<
Tensioning bracket (V-8)
(Tool No. BMW 11 7 380)
Compressed air fitting for testing VANOS operation
((Tool No. BMW 11 3 450)
<
Upper timing cover installation tool set, V-8
(Tool No. BMW 11 1 41 0)
Cylinder compression, checking
A compression gauge is needed to make a compression test.
For accurate test, the battery and starter must be capable of
cranking the engine at least 300 rpm, and the engine should
be at normal operating temperature.
NOTE-
Performing a compression test may cause a fault to set in the
ECM and may illuminate the Malfunction Indicator Light
(MIL). The light can only be turned out using either BMW
special service scan tools or an equivalent aftermarket scan
tool. Disconnecting the battery will not erase the fault memo-
ry or turn out the light. See OBD On-Board Diagnostics.