Failure mode - Ford 6.7L Power Stroke Diesel (Scorpion)

Intercooler condensation ingestion + cold-side charge-pipe fatigue

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

Symptoms

a momentary shudder, stumble, or brief misfire on hard acceleration after extended light-load driving in humid weather, sometimes with a puff of white vapor from the exhaust
underboost code P0299 with a hissing/whooshing sound under load, WITHOUT the turbo bearing-noise signature of VGT turbocharger failure - generation dependent (ceramic-bearing GT32 vs...
visible oil-misted water at charge-pipe connections on inspection
repeated misfire codes with no corresponding injector-balance fault

Compare with the other causes of the same sign on this engine: white smoke from the exhaust (3 causes) · ticking, knocking, rattle or whine (3 causes) · misfire, rough idle, hesitation or surging (5 causes)

Root cause

The 6.7L's air-to-water intercooler is compact and efficient enough that, under light load in humid conditions, moisture in the intake air condenses inside the cooler and pools in the charge-air plumbing; a hard acceleration then ingests that water slug at once, producing the stumble/misfire. Separately, the molded plastic cold-side charge pipe carrying boost from the intercooler to the intake can fatigue and split at its bellows or end fittings, particularly on trucks run at elevated boost (tuned or towing hard) - producing sudden power loss and a P0299 that has nothing to do with the turbocharger itself. This mode is NOT present in this dataset's other Power Stroke/Cummins platforms - it is specific to the 6.7L's intercooler/charge-pipe design and worth its own record rather than folding into the turbo mode.

Diagnosis

pressure-test the charge-air circuit (system capped, soapy water or a smoke machine at the joints) BEFORE condemning the turbocharger for a P0299 - this is one of the most common non-turbo causes of that code on this platform
owners frequently mistake the condensation-ingestion stumble for injector or transmission trouble - rule out a corresponding injector-balance fault first
inspect the intercooler end tanks and boots at both ends for oil accumulation, which usually traces back to turbo seal seepage (VGT turbocharger failure - generation dependent (ceramic-bearing GT32 vs...) rather than this mode's own mechanism

Fixes

replace a failed/split cold-side charge pipe with an upgraded unit ()

charge-pipe - more than one option: Banks Power Boost Tube System, hot and cold side (2011-2016 6.7L Power Stroke) (upgrade option), Banks Power Boost Tube System, hot and cold side (2017-2026 6.7L Power Stroke, standard output) (upgrade option), Banks Power Boost Tube System, hot and cold side (2023-2026 6.7L Power Stroke, High Output) (upgrade option)

for condensation ingestion: no part fix - working the truck harder on a regular basis keeps the cooler dry; Ford also issued revised calibrations/hardware over the years per the vendor source (not itemized further here) ()

Prevalence

occasional