6.4 HEMI (gas): misfire, rough idle, hesitation or surging

3 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.

Lifter / cam wear (HEMI tick source #2) Common · 17 complaints · 2 recall/bulletins
Ignition service wear (plugs / coils) Common
EGR valve carbon (gas EGR service surface) Occasional

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 Lifter / cam wear (HEMI tick source #2)

aggregated How widespread: Common 17 NHTSA owner complaints match it, out of 80 checked

How it shows up

misfire / dead cylinder on one bank

Its other signs

constant valvetrain tick that does not warm-and-quiet
metallic debris in the oil on neglected cases

How to tell it apart

confirm constant (valvetrain) vs warm-and-quiet (exhaust) tick first - the cheap confusion is expensive
oil-pressure check and filter cutting before teardown
on a confirmed lifter: inspect the matching cam lobe - a flaked lobe means cam replacement; identify standard vs deactivating lifters per cylinder position before ordering

Usual fix

replace lifter(s) / cam as inspection dictates; flush and correct the oil service interval afterwards

Recalls and bulletins

9100229 STAR S1709000010 (Rev., Rev. B)

Root cause, parts and sources →

2 Ignition service wear (plugs / coils)

aggregated How widespread: Common

How it shows up

rough idle / misfire as plugs age; coils fail individually

How to tell it apart

pull plug condition at service mileage; replace as a set on an aged engine
test coils on a miss before bulk replacement

Usual fix

service: plugs + coils as wear parts

Root cause, parts and sources →

3 EGR valve carbon (gas EGR service surface)

aggregated How widespread: Occasional

How it shows up

EGR flow / position codes, rough idle or hesitation at light load

Its other signs

less frequent than on the diesel sibling but recurring at higher mileage

How to tell it apart

read codes and command the valve; verify flow before replacement
inspect intake-side carbon when the valve is out

Usual fix

service: replace the EGR valve / clean paths; keep the system intact and functional

Root cause, parts and sources →

Other symptoms on the 6.4 HEMI (gas)

Ticking, knocking, rattle or whine

Everything on the 6.4 HEMI (gas)Its 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.