The 2004 Altima is split between a reliable 2.5L four-cylinder and a problematic 3.5L V6 that suffers catastrophic pre-cat failure, plus CVT transmission issues that plague both engines. The QR25DE is solid; the VQ35DE is a ticking time bomb.
Pre-Catalytic Converter Failure Leading to Engine Destruction (3.5L V6 Only)
Common · high severity
Typical onset: 70,000-120,000 mi
Symptoms: Rattling from engine bay on cold start that disappears when warm, Loss of power and rough idle, Check engine light with multiple misfire codes (P0300-P0306), Metallic debris in oil during changes, Catastrophic engine failure if driven after symptoms appear
Fix: The pre-cats inside the exhaust manifolds disintegrate and get sucked back into cylinders, scoring cylinder walls and destroying pistons/rings. Requires complete engine rebuild or replacement. Preventive fix is replacing factory manifolds with aftermarket units before failure (8-10 hours labor). Post-failure needs full rebuild with bore/hone or short block swap (25-35 hours).
Estimated cost: $4,500-8,500
CVT Transmission Failure (RE4F04B)
Common · high severity
Typical onset: 80,000-130,000 mi
Symptoms: Whining or grinding noise during acceleration, Shuddering between 15-30 mph, Hesitation or slipping when accelerating from stop, Transmission overheating warning light, Sudden loss of forward gears
Fix: These early CVTs have weak valve bodies and fail bearings. Transmission cooler lines also leak into radiator causing cross-contamination (the 'strawberry milkshake of death'). Flush and external cooler addition extends life but most need full replacement or rebuild. R&R is 8-10 hours; rebuilt units run $2,500-3,200 plus installation.
Estimated cost: $3,200-4,800
Crankshaft Position Sensor Failure
Common · medium severity
Typical onset: 60,000-110,000 mi
Symptoms: No-start condition with cranking but no fire, Intermittent stalling while driving, especially when hot, Check engine light with P0335 or P0340 codes, Engine cuts out then restarts after cooling
Fix: Sensor mounted on bellhousing fails from heat cycling. Common failure point that leaves you stranded but easy fix. Replace sensor and connector pigtail if corroded (1.5-2 hours labor). Always replace when doing transmission work as access is same.
Estimated cost: $180-320
Front Lower Control Arm Bushing Deterioration
Common · low severity
Typical onset: 70,000-100,000 mi
Symptoms: Clunking over bumps from front end, Steering wheel off-center after hitting potholes, Uneven tire wear on inside edges, Wandering or loose steering feel
Fix: Front LCA bushings crack and separate, most common on driver side. Cannot press new bushings into old arms on this chassis—must replace complete control arms. Both sides plus alignment is 2.5-3 hours. Always do both sides and alignment together.
Estimated cost: $400-650
Exhaust Manifold Stud Failure (2.5L I4)
Occasional · medium severity
Typical onset: 90,000-140,000 mi
Symptoms: Ticking noise from engine that increases with RPM, Exhaust leak smell in cabin with heat on, Visible soot around manifold flange, Failed emissions test due to leak pre-O2 sensor
Fix: Studs corrode and snap at cylinder head. Middle studs most common. Requires manifold removal and extraction of broken studs, often need helicoil inserts. 4-6 hours labor depending on how many studs break during removal. Use anti-seize on reinstall.
Estimated cost: $500-950
Headlight Wiring Harness Melting
Occasional · medium severity
Symptoms: One or both low beams intermittent or dead, Melted plastic smell near headlights, Headlight bulbs burn out repeatedly, Flickering headlights
Fix: Factory harness undersized for current draw, connector melts at bulb socket. Multiple NHTSA recalls but not all VINs covered. Requires replacement pigtail or entire harness depending on damage (1-2 hours per side). Upgrade to relayed harness prevents recurrence.
Estimated cost: $150-400
Engine and Transmission Mount Failure
Common · low severity
Typical onset: 80,000-120,000 mi
Symptoms: Excessive vibration at idle in drive, Clunk when shifting from reverse to drive, Engine rocks visibly when revving in park, Harsh engagement into gear
Fix: Hydraulic mounts crack and leak fluid. Front mount and transmission mount most common. Replace all three mounts at once (upper strut tower, front, and trans mount) as labor overlaps. Total 3-4 hours for all three. OEM mounts preferred over aftermarket.
Estimated cost: $450-750
Owner tips
If buying a 3.5L V6, inspect for pre-cat failure FIRST—listen for cold-start rattle and check oil for metal flakes; budget $1,000 for preventive manifold replacement immediately
Change CVT fluid every 30,000 miles with Nissan NS-2 fluid only; add external transmission cooler if towing or hot climate
The 2.5L QR25DE is far more reliable than the VQ35DE—if choosing between them, take the four-cylinder
Keep spare crank position sensor in glovebox on high-mileage examples—$40 part prevents being stranded
Buy the 2.5L four-cylinder with manual transmission only; avoid the 3.5L V6 and CVT combination unless pre-cat fix is documented and you have $5K set aside for transmission replacement.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.
Fitment notes: Standard engine bay mounting; verify terminal orientation before purchase
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Every control module on the 2002-2006 Nissan Altima — where it lives, replacement time, and what it takes to program a replacement. Modules marked dealer / factory tool won't work after a part swap alone — budget for programming.
Electric Power Steering Control Unit (EPS)2.5 hr R&Rrelearn only +0.3 hr2002-2003 4-cylinder models only▸ programming details
📍 Integrated with steering column assembly, under lower dash
🔧 CONSULT-II or aftermarket scan tool
⚠️ Column-mounted electric power steering on early 4-cylinder models. 2004+ and all V6 models use conventional hydraulic power steering without control module. Steering angle sensor calibration required after replacement.
Anti-lock Brake System Control Unit (ABS)1.5 hr R&Rrelearn only +0.3 hr▸ programming details
📍 Engine bay, driver side strut tower, mounted to ABS hydraulic unit
🔧 CONSULT-II or aftermarket scan tool
⚠️ Integrated with hydraulic unit and brake booster. Brake bleeding and ABS initialization required after replacement. Standard equipment all trims.
📍 Passenger side floor, under carpet near center console
🔧 CONSULT-II with NDS
⚠️ RE4F04B (4-cyl) and RE5F22A (V6) transmissions. Adaptive learning reset required after installation; may take 10-20 drive cycles to relearn shift points.
Auto Air Conditioner Control Unit (A/C)1.1 hr R&Rno codingautomatic climate control only
📍 Behind center dash climate control panel
⚠️ Manual HVAC on base 2.5 and 2.5 S trims uses mechanical controls without module. Auto climate control on 3.5 SE and SE-R trims.
Supplemental Restraint System Control Module (SRS)1.0 hr R&Rrelearn only +0.2 hr▸ programming details
📍 Center console, under climate control/radio stack, behind center trim
🔧 CONSULT-II or aftermarket scan tool
⚠️ Wait 3+ minutes after battery disconnect before servicing. Crash data stored; clearing required after collision repairs. Side airbags and curtains on SE-R and 3.5 SE models.
📍 Engine bay, passenger side firewall, mounted on bulkhead near brake master cylinder
🔧 CONSULT-II with NDS
⚠️ QR25DE (4-cyl) and VQ35DE (V6) use different ECMs. NATS immobilizer integrated; key registration required after replacement. 2005-2006 models may support some aftermarket programming tools.
Body Control Module (BCM)0.9 hr R&Rdealer / factory tool +0.4 hr▸ programming details
📍 Driver side kick panel, behind lower dash trim panel
🔧 CONSULT-II with NDS
⚠️ Controls exterior lighting, power windows, door locks, keyless entry receiver, interior lighting. VIN programming required for replacement.
Sonar Control Unit (SONAR)0.8 hr R&Rno codingwith rear parking sensors (3.5 SE option)
📍 Trunk, driver side rear quarter panel area
⚠️ Rear parking assist optional on 3.5 SE trim 2005-2006 model years. Four ultrasonic sensors in rear bumper.
⚠️ Odometer stored in cluster EEPROM. Mileage programming required when replacing; dealer must document per federal odometer disclosure laws. Communicates with ECM and BCM via CAN bus.
Audio Control Unit (AUDIO)0.6 hr R&Rrelearn only +0.1 hr▸ programming details
📍 Center dash, in radio mounting location
🔧 Radio anti-theft code entry
⚠️ Factory Bose systems have separate amplifier in trunk. Anti-theft code required after battery disconnect or replacement; code on card in owner's manual or retrievable from serial number.
NATS Control Unit (NATS)dealer / factory tool +0.8 hr▸ programming details
📍 Integrated within ECM
🔧 CONSULT-II with NDS and PIN code
⚠️ Nissan Anti-Theft System standard all models. Key registration requires 4-digit PIN code obtained from Nissan via VIN. Maximum 5 keys can be registered. ECM replacement requires all keys to be re-registered.
Aftermarket tool coverage varies by software version and vehicle build — treat "aftermarket tool" rows as "usually possible" and verify against your tool maker's coverage list before promising a customer. Spot a wrong location or hour? Tell us — corrections ship fast here.
CERTAIN EAGLE EYES HEADLAMP ASSEMBLIES, P/NOS. DS517-B001L AND DS517-B001R, SOLD FOR USE AS REPLACEMENT EQUIPMENT FOR THE ABOVE LISTED PASSENGER VEHICLES. THE OPTICEL SURFACE OF THE REFLECTOR IS CORRODED INHIBITING THE PERFORMANCE OF THE UPPER AND LOWER BEAMS WHICH FAILS TO CONFORM TO THE PHOTOMETRIC REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 108, LAMPS, REFLECTIVE DEVICES, AND ASSOCIATED EQUIPMENT.
Consequence: DECREASED LIGHTING VISIBILITY MAY RESULT IN A VEHICLE CRASH.
Remedy: EAGLE EYES WILL NOTIFY OWNERS AND OFFER REIMBURSEMENT FOR ANY NONCOMPLIANT HEADLIGHTS. THE RECALL BEGAN ON DECEMBER 11, 2007. OWNERS MAY CONTACT EAGLE EYES AT 1-800-568-1098.
EXTERIOR LIGHTING:HEADLIGHTS · 07E063000
2007-08-21
CERTAIN ANZO AFTERMARKET HEADLIGHTS, P/N 02-AZ-NA02-B-A, SOLD FOR USE ON 2002-2004 NISSAN ALTIMA VEHICLES. DURING PRODUCTION THE LAMP HOUSING SHAPE DEFORMED DISTORTING THE ASSEMBLY ANGLE OF THE REFLECTOR AND INFLUENCED THE AIMING POSITION. THESE HEADLAMPS FAIL TO CONFORM TO THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 108, LAMPS, REFLECTIVE DEVICES, AND ASSOCIATED EQUIPMENT.
Consequence: DECREASED LIGHTING VISIBILITY MAY RESULT IN A VEHICLE CRASH.
Remedy: ANZO WILL NOTIFY OWNERS AND OFFER A FULL REFUND FOR THE NONCOMPLIANT LAMPS. THE RECALL BEGAN ON SEPTEMBER 10, 2007. OWNERS CAN CONTACT ANZO AT 909-628-1440.
EXTERIOR LIGHTING:HEADLIGHTS · 07E054000
2007-07-25
CERTAIN MAXZONE HEADLIGHT ASSEMBLIES, DEPO BRAND, P/NOS. 315-1145L-AS AND 315-1145R-AS, SOLD FOR USE AS AFTERMARKET EQUIPMENT FOR THE ABOVE LISTED PASSENGER VEHICLES. DURING PRODUCTION THE LAMP REFLECTOR SHAPE DEFORMED CHANGING THE SHAPE OF THE OPTIC SURFACE. THIS WILL CHANGE THE OPPOSITE POSITION OF LOW BEAM AND HIGH BEAM OPTICSAND CHANGE THE ANGLE OF INCIDENCE AND ILLUMATED LOCATION WHICH FAILS TO CONFORM TO THE REQUIREMENTS OF FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 108, LAMPS, REFLECTIVE DEVICES, AND ASSOCIATED EQUIPMENT.
Consequence: DECREASED LIGHTING VISIBILITY MAY RESULT IN A VEHICLE CRASH.
Remedy: MAXZONE WILL NOTIFY OWNERS AND OFFER REIMBURSEMENT FOR ANY NONCOMPLIANT HEADLIGHTS. THE RECALL BEGAN ON JULY 16, 2007. OWNERS MAY CONTACT MAXZONE AT 909-822-3288.
ENGINE AND ENGINE COOLING · 06V242000
2006-07-07 · RQ06001
ON CERTAIN PASSENGER VEHICLES EQUIPPED WITH A 2.5L ENGINE, THE CRANK ANGLE SENSOR IS AFFECTED BY TEMPERATURE VARIATIONS. UNDER CERTAIN DRIVING CONDITIONS, THESE VARIATIONS IN TEMPERATURE CAN BE LARGE ENOUGH TO CAUSE A BRIEF INTERRUPTION IN THE SIGNAL OUTPUT FROM THE SENSOR.
Consequence: IF THE INTERRUPTION IN THE SIGNAL FROM THE SENSOR IS SO BRIEF THAT THE ELECTRONIC CONTROL MODULE (ECM) LOGIC DOES NOT HAVE TIME TO DIAGNOSE THE CONDITION, THE ENGINE MAY STOP RUNNING WITHOUT WARNING WHILE THE VEHICLE IS DRIVEN AT A LOW SPEED INCREASING THE RISK OF A CRASH.
Remedy: DEALERS WILL REPROGRAM THE ECM FREE OF CHARGE. THE RECALL BEGAN ON AUGUST 21, 2006. OWNERS MAY CONTACT NISSAN AT 1-800-647-7261.
EXTERIOR LIGHTING:HEADLIGHTS · 06E023000
2006-03-13
CERTAIN ANZO COMBINATION HEADLAMP ASSEMBLIES SOLD AS REPLACEMENT LAMPS FOR USE ON CERTAIN PASSENGER VEHICLES. SOME COMBINATION LAMPS ARE NOT EQUIPPED WITH AMBER SIDE REFLECTORS WHICH FAIL TO CONFORM TO FEDERAL MOTOR VEHICLE SAFETY STANDARD NO. 108, "LAMPS, REFLECTIVE DEVICES, AND ASSOCIATED EQUIPMENT."
Consequence: WITHOUT THE AMBER REFLECTORS, THE VEHICLE WILL BE POORLY ILLUMINATED, POSSIBLY RESULTING IN A VEHICLE CRASH.
Remedy: ANZO WILL NOTIFY OWNERS AND REPLACE THE HEADLAMPS FREE OF CHARGE. THE RECALL BEGAN MAY 9, 2006. OWNERS MAY CONTACT ANZO USA AT 909-468-3688.
Fuel economy (EPA)
City
20mpg
Highway
28mpg
Combined
23mpg
Fuel
Regular Gasoline
Capability & size
EPA class
Midsize Cars
Wiper blades
2002-2006 Altima (L31) generation, sedan body style, no rear wiper
Size-standard part numbers — verify your connector type before buying. Rear blades are model-specific; check the package's vehicle list.
Fuel economy figures are EPA data via fueleconomy.gov (median across matching trims). Performance figures are compiled estimates for the 2004 Nissan Altima 2.5L I4 QR25DE and can vary by trim.
🔧 Database maintained under the daily editorial review of Chris Hackleman · Master Technician · 20+ years and Jeff Moore · Master Lexus & Toyota Mechanic · 20+ years.