170-2
Troubleshooting
Begin the diagnosis of cooling system
problems with a thorough visual
inspection. If no visual faults are found,
it is recommend that the DME system
be checked for stored diagnostic fault
codes (DTCs) using BMW scan tools
DIS (Diagnostic Information System) or
MoDiC (Mobile Diagnostic Computer) or
an aftermarket equivalent.
Common cooling system faults can be
grouped into one of four categories:
Cooling system leaks
Poor coolant circulation
Radiator cooling fan faults
Electrical/electronic faults
Be sure to check the condition and
tension of the coolant pump drive belt.
Check hoses for cracks or softness.
Check clamps for looseness. Check
the coolant level and check for
evidence of coolant leaks from the
engine.
Check that the radiator fins are not
blocked with dirt or debris. Clean the
radiator using low-pressure water or
compressed air. Blow outward, from
the engine side out.
To check coolant pump:
Lever tensioner clockwise using
wrench on hex (large arrow) and
slip belt off pulley.
Firmly grasp opposite sides of
Radiator and Cooling System
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Summary of Contents for 1999-2005 M3
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