Heater hoses, including the heated wiper fluid line, head gasket (check for residue from HG itself)--also check oil for milky substance and antifreeze for sludge, and also isn't there a freeze plug somewhat above (but forward of) the starter on the M104s? Usually the antifreeze in these cars turns white and powdery as it dries up...a nice mess if your radiator ever blows

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TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth