Failure mode - Cummins 6.7L ISB Diesel (Ram HD)

Grid heater 'killer bolt' ingestion

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

Symptoms

P2609 (intake air heater circuit) or a check-engine light can come first: owners report the code when the hardware has started to burn or break
sudden loss of power, knocking or clicking, then catastrophic engine damage once a broken nut or bolt reaches a cylinder (owners most often name cylinder #6)
hard cold starts / no grid-heater cycling when the heater itself has failed separately
the grid-heater terminal nut or bolt visibly burned, loose or broken on inspection (found before it lets go)

Compare with the other causes of the same sign on this engine: hard start, long crank or no-start (2 causes) · loss of power, limp mode or derate (6 causes) · ticking, knocking, rattle or whine (7 causes)

Root cause

The intake air heater (grid heater) sits in the intake horn, downstream of the turbo and intercooler, and its power terminal carries high current through a small nut and bolt inside the intake. Heat, vibration and arcing deteriorate that hardware; if the nut or bolt breaks off it is pulled into the intake manifold and into a cylinder, damaging the piston, valves and head. Owner complaints most often name cylinder #6. Documented across 2007.5-2024 (both this platform and the 2019+ generation). Correction 2026-10-10: an earlier version of this record said the bolt is ingested into the turbo compressor; the heater is downstream of the turbo, and NHTSA narratives describe cylinder damage, not turbo damage.

Diagnosis

treat a P2609 / intake heater code as a reason to inspect the grid heater hardware before driving further
remove the intake horn and inspect the grid heater terminal nut and bolt for burning, looseness or breakage (shop check at any service visit)
after a failure: borescope the cylinders (owners most often report #6) and inspect the intake manifold for missing hardware before restarting

Fixes

prophylactic: replace the factory grid heater with a retention/upgrade kit or an intake design without the internal fastener - cheap insurance against engine damage ()

6.7 Cummins Grid Heater Bolt Retention Kit
grid-heater - more than one option: Banks Power Billet Heater Kit, 1500W (2007-2018 Ram 6.7L Cummins; requires Monster-Ram installed) (upgrade option), Banks Power Billet Heater Kit, 750W (2007-2018 Ram 6.7L Cummins; requires Monster-Ram installed) (upgrade option), Banks Power Dual Heater Upgrade Kit (2007-2018 Ram 6.7L Cummins; requires Triple-Heat-capable Monster-Ram) (upgrade option), Banks Power Monster-Ram Intake & Killer Grid Heater Upgrade (2007.5-2012 Ram 2500/3500 pickup, 6.7L Cummins) (upgrade option), Banks Power Monster-Ram Intake & Killer Grid Heater Upgrade, Chassis Cab (2007.5-2012 Ram 3500/4500/5500, 6.7L Cummins) (upgrade option), Banks Power Monster-Ram Intake & Killer Grid Heater Upgrade (2013-2018 Ram 2500/3500 pickup, 6.7L Cummins) (upgrade option), Banks Power Monster-Ram Intake & Killer Grid Heater Upgrade, Chassis Cab (2013-2018 Ram 3500/4500/5500, 6.7L Cummins) (upgrade option)

after ingestion: cylinder head and piston repair or engine replacement, plus intake inspection for remaining debris ()

vgt-turbo - more than one option: Holset HE351VE VGT Turbo (2007.5-2012 pickup), Holset HE351VE VGT Turbo - Mopar Reman (2007.5-2012 pickup, current PN R8048234AI), Holset HE300VG VGT Turbo (2013-2018 pickup)

Prevalence

common

Parts for this repair run about $270-$820: see them next to the other repairs on this engine in repair costs.