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Symptoms · 5.9 Cummins (1994-2007)
5.9 Cummins (1994-2007): misfire, rough idle, hesitation or surging
2 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.
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.
verified
How widespread: Common
How it shows up
- cold-start rattle and white smoke that clears warm; uneven idle; rising fuel consumption
Its other signs
- metal-on-metal tick from a failing injector; copper crush washer blow-by at the sleeve
How to tell it apart
- balance-rate test (bidirectional scan tool or dealer test) pinpoints the weak injector before replacing a set
- inspect connector tubes and copper washers for blow-by soot
Usual fix
replace the worn injector(s) with new/reman units; new copper washers and connector-tube seals every time
Root cause, parts and sources →
verified
How widespread: Common
How it shows up
- dying pump symptoms: hard starts, dead pedal above ~2000 rpm, surging, then no-start
Its other signs
- often follows weeks of low fuel pressure the driver could not see (no stock gauge)
How to tell it apart
- install a fuel pressure gauge (the single best 24v upgrade) - under 5 psi at the VP44 inlet means the lift pump is dying
- verify lift pump output before condemning the VP44; a new VP44 on a dying lift pump repeats the failure
- scan for VP44 DTCs (P1688/P1689/P0216 etc.)
Usual fix
replace the VP44 and fix the fuel supply as one job: new/remanned pump + lift pump (relocated) + gauge
Root cause, parts and sources →
Other symptoms on the 5.9 Cummins (1994-2007)
Hard start, long crank or no-startLoss of power, limp mode or derateWhite smoke from the exhaustLosing coolantTicking, knocking, rattle or whine
Everything on the 5.9 Cummins (1994-2007)Its recalls and bulletins