Failure mode - Ford 6.2L Boss Gasoline (Super Duty 2011-2019, SVT Raptor 2010-2014; continued 2020-2022)

Exhaust valve seat wear (early builds)

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

Symptoms

progressive rough idle and misfires that worsen when hot
low / uneven compression across cylinders on early-build engines
valve lash drifting out of spec between services

Compare with the other causes of the same sign on this engine: misfire, rough idle, hesitation or surging (2 causes)

Root cause

Early-run 6.2L engines are documented (vendor + owner record) with exhaust valve seat recession; Ford updated seat hardware during the early production window. Later builds carry the updated seats. No authoritative failure-rate statistics are cited in the open record.

Diagnosis

compression / leak-down test per cylinder, hot and cold
check valve lash and recorded idle quality before teardown
on confirmed recession: head service with updated exhaust seats

Fixes

head service with updated exhaust-valve-seat hardware; verify the machine shop installs the updated seats ()

valvetrain - more than one option: 6.2L Boss Rocker Arm, right (OEM), 6.2L Boss Valve Tappet (OEM), 6.2L Boss Valve Spring, 2011-2013 (OEM), 6.2L Boss Valve Spring, 2017-2019 (OEM)

Prevalence

occasional