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Symptoms · 6.7 Cummins 2007-2018

6.7 Cummins 2007-2018: loss of power, limp mode or derate

6 documented failures on this engine list this among their signs. They are ordered from the most widespread down. Each one shows the signs in its record's own words, how to tell it from the others, the usual fix and any recall or bulletin.

  1. DPF clogging / regeneration problems Very common · 55 complaints · 3 recall/bulletins
  2. Holset VGT turbo sticking / actuator failure Very common · 40 complaints · 1 recall/bulletin
  3. DEF / SCR system failures (2013-2018) Common · 43 complaints
  4. Lift pump / fuel delivery weakness Common · 32 complaints · 1 recall/bulletin
  5. Grid heater 'killer bolt' ingestion Common · 17 complaints · 2 recall/bulletins
  6. EGR valve sooting / failure Common · 16 complaints

Not sure which engine you have, or want the recalls for your exact truck? Check your VIN: it names the engine and lists the campaigns for that model year. Whether a recall is still open on your VIN: nhtsa.gov/recalls.

1 DPF clogging / regeneration problems
verified How widespread: Very common 55 NHTSA owner complaints match it, out of 1,355 checked

How it shows up

  • loss of power (inducement / derate) until regeneration completes
Its other signs
  • 'exhaust filter full / regeneration required' message on the overhead console
  • frequent or endless regenerations; aborted regens on short trips
  • excessive idle, white/grey smoke during regen, hot exhaust smell
  • fuel smell in the oil after repeated failed regens

How to tell it apart

  • read DTCs (P242F/P2463 soot-load, P204F etc.) and soot-load / ash-load PIDs before replacing anything
  • verify regen completes when driven at highway load (30+ min); a filter that regens clean is a duty-cycle problem, not a part problem
  • differential-pressure check across the DPF; inspect for cracked/missing substrate

Usual fix

restore duty cycle: sustained highway load so regens complete; correct the underlying reason regens fail (VGT, sensors, EGR) before replacing the filter

Recalls and bulletins

TSB 18-002-14 REV. BTSB 18-002-14 REV. ATSB 18-002-14

Root cause, parts and sources →

2 Holset VGT turbo sticking / actuator failure
verified How widespread: Very common 40 NHTSA owner complaints match it, out of 1,355 checked

How it shows up

  • low power / boost DTCs (over/underboost), smoky acceleration
Its other signs
  • loss of exhaust-brake function (the classic first sign - the VGT is the exhaust brake)
  • turbo actuator DTCs; 'Service Electronic Throttle'?
  • excessive idle/lope or whistle change; failed regens because the turbo cannot build regen heat

How to tell it apart

  • actuator/nozzle-position DTCs and live vane-position PID vs commanded - stuck or lagging vane position is the tell
  • test the exhaust brake at cold start: no RPM dip / braking effect = nozzle not closing
  • inspect vane motion with the actuator commanded (shop tool); look for soot coke in the turbine housing

Usual fix

replace the electronic actuator alone when vanes move freely but the actuator is dead (cheaper than a turbo)

Recalls and bulletins

TSB 11-001-08

Root cause, parts and sources →

3 DEF / SCR system failures (2013-2018)
verified How widespread: Common 43 NHTSA owner complaints match it, out of 1,355 checked

How it shows up

  • DEF-system warning / 'service DEF system' message, then 5 mph derate if ignored
Its other signs
  • NOx sensor DTCs (P2200-family); 'DEF quality poor' messages
  • DEF pump / heater failure, especially after a freeze (pump assembly contains a heater)
  • white crystalline urea deposits around the DEF tank, pump and injector
  • failed emissions test / MIL with no driveability change

How to tell it apart

  • read DEF/SCR DTCs and current DEF quality / NOx PIDs before parts-cannoning
  • inspect DEF for contamination/crystals; sample age - DEF has a shelf life and degrades with heat
  • verify tank heater and pump operation on a cold morning (freeze-related no-starts of the dosing system)

Usual fix

drain and flush contaminated DEF; fresh DEF (dated stock, stored cool); clear crystals from the injector

Root cause, parts and sources →

4 Lift pump / fuel delivery weakness
verified How widespread: Common 32 NHTSA owner complaints match it, out of 1,355 checked

How it shows up

  • long cranks, hesitation, power loss when the tank is low
Its other signs
  • P0087 / low-rail-pressure DTCs, worse under load or with tuning
  • FCA (fuel control actuator) ticking / rough idle when failing
  • water-in-fuel warnings if filtration is neglected

How to tell it apart

  • measure supply/return fuel pressure under load (the decisive test) - spec per service data
  • scan rail-pressure actual vs desired under a load test; P0087 points delivery-side first
  • isolate FCA vs lift pump: FCA symptoms (ticking/rough idle) vs delivery starvation under load

Usual fix

replace the worn lift pump with a stock-type in-tank unit (stock trucks)

Recalls and bulletins

TSB 08-036

Root cause, parts and sources →

5 Grid heater 'killer bolt' ingestion
verified How widespread: Common 17 NHTSA owner complaints match it, out of 1,355 checked

How it shows up

  • 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)
Its other signs
  • 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
  • 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)

How to tell it apart

  • 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

Usual fix

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

Recalls and bulletins

TSB 9003585TSB 18-005-13

Root cause, parts and sources →

6 EGR valve sooting / failure
verified How widespread: Common 16 NHTSA owner complaints match it, out of 1,355 checked

How it shows up

  • rough idle, smoke, occasional power loss; failed regens
Its other signs
  • EGR flow DTCs (P0401/P0402/P0404-family), check-engine light
  • valve found coked with soot on inspection

How to tell it apart

  • read EGR DTCs and commanded-vs-actual valve position PID
  • remove and inspect for coke; clean vs replace decision follows condition
  • check the EGR cooler and CCV filter state at the same time - they share the soot/oil load

Usual fix

clean the valve (if pintle moves freely after cleaning, reinstall); replace when worn/stuck

Root cause, parts and sources →

Other symptoms on the 6.7 Cummins 2007-2018

Hard start, long crank or no-startWhite smoke from the exhaustLosing coolantOverheating or temperature creeping upOil leak, oil consumption or rising oil levelTicking, knocking, rattle or whineMisfire, rough idle, hesitation or surgingDEF, DPF and regeneration warnings

Everything on the 6.7 Cummins 2007-2018Its recalls and bulletins

Order: how widespread each failure is in its record (near-universal, very common, common, occasional, rare), then the number of NHTSA owner complaints that match its keywords. Complaint counts are keyword matches, not a manual review of each complaint. A symptom listed here means the failure is documented with that sign; it is not a diagnosis of your truck. Tiers: verified, aggregated, contested, data-gap. How we tier and source facts.