17 00 010 Checking for leaks between cooling system and combustion chamber
WARNING: This page is about a different car, the 2003 BMW 525i, 2002 BMW 525i, and 2001 BMW 525i. However, it is still accessible from the selected car via links, so may be relevant.
WARNING:
Danger of scalding! Only perform this work after engine has cooled down.
CAUTION:
When engine is running with cooling system depressurized, this can create steam bubbles. These cause the engine to overheat. Observe coolant temperature.
Check for leaks in cylinder head with CO leak tester following manufacturer's instructions for use.
In the event of a leak, the color of the test liquid turns yellow by the carbon dioxide (combustion gas) entering the cooling system.