Failure mode - Ford 6.4L Power Stroke

Front-cover pump cavitation erosion (coolant into oil)

Reliability tier: verified - verify before ordering, see /disclosure/

Symptoms

milky oil / rising oil level (coolant entering the crankcase via the eroded cover)
external coolant seep at the front cover in earlier stages
overheating history; low-coolant top-ups precede it

Root cause

The vacuum-pump/high-pressure-oil pump bore through the front cover cavitates (sourced history names the mode), eroding the wall until coolant crosses into oil - an engine-out repair when advanced. Coolant maintenance (SCA levels) is the cited driver.

Diagnosis

milky oil / oil-analysis for coolant metals = advanced; check the front cover externally first
pressurise the cooling system and inspect the crankcase/oil for entry
ultrasound the cover thickness at rebuild time

Fixes

engine-level: replace/rebuild with a repaired cover (specialist service exists); at rebuild, treat SCA/coolant discipline as mandatory ()

engine-long-block (part category - specific model not chosen)

coolant maintenance discipline (spec coolant + SCA) to prevent recurrence ()

coolant (part category - specific model not chosen)

Prevalence

occasional