1998 NISSAN ALTIMA

Typical onset: 120,000-180,000 mi

Symptoms: Metallic rattling/knocking especially under load or acceleration, Loss of power, rough idle, misfires, Metal shavings in oil, low oil pressure, Sudden catastrophic failure with rod knock

Fix: KA24DE engines are sensitive to carbon buildup and low-octane fuel causing pre-ignition that hammers rod bearings, cracks piston skirts, and scores cylinder walls. Requires full teardown: piston rings minimum (12-16 hours), often needs pistons, rods, bearings, sometimes crank work and cylinder honing. Many shops recommend short block replacement (18-24 hours) over rebuild given age.

Estimated cost: $2,800-5,500

Typical onset: 90,000-150,000 mi

Symptoms: Transmission slipping, delayed engagement, or complete failure, Milky pink/brown transmission fluid (strawberry milkshake appearance), Overheating transmission, erratic shifting, Coolant loss without external leaks

Fix: Cooler is integrated into the radiator; internal failure lets coolant mix with ATF, destroying clutch packs and valve body within days. Requires radiator replacement, complete ATF system flush (3-4 hours minimum), often too late and needs transmission rebuild or replacement (8-12 hours R&R plus rebuild). Preventive radiator replacement at 100k saves the transmission.

Estimated cost: $1,200-4,000

Typical onset: 80,000-120,000 mi

Symptoms: Clunking when shifting from Park to Drive/Reverse, Excessive engine movement visible under hood during acceleration, Vibration through chassis at idle, Shifter feels sloppy or imprecise

Fix: Front transmission mount (also supports engine) fails due to heat and fluid contamination. Rubber separates from metal, causing drivetrain to shift excessively. Replacement takes 1.5-2.5 hours depending on access, should inspect all engine mounts simultaneously.

Estimated cost: $180-350

Typical onset: 100,000-140,000 mi

Symptoms: Hard starting, especially when hot, Hesitation, stumbling, or stalling under load, Loss of power at highway speeds, Check engine light with lean codes

Fix: In-tank fuel filter and pump assembly prone to clogging from sediment buildup, especially if regular filter changes were skipped (Nissan spec: 30k intervals, often ignored). Requires fuel tank drop for filter/pump access (2.5-3.5 hours). Many techs replace entire pump assembly rather than filter alone for longevity.

Estimated cost: $350-650

Symptoms: One or both headlights intermittent or completely out, High beams work but low beams don't (or vice versa), Headlights flicker or dim randomly, Melted connector at headlight plug

Fix: Headlight circuit runs high amperage through aging connectors and relays, causing heat buildup and connector melt. NHTSA recalls addressed some batches but problem persists. Requires relay replacement, often pigtail connector repair/replacement at headlight socket (1-2 hours). Upgrade to relayed harness prevents recurrence.

Estimated cost: $120-280

Typical onset: 90,000-130,000 mi

Symptoms: Clunking or popping over bumps at low speed, Grinding or creaking when turning steering wheel while stationary, Steering feels notchy or catches at certain positions, Uneven tire wear on front

Fix: Upper strut mount bearings seize or fail, affecting steering feel and causing noise. Related to NHTSA suspension recall but broader than recall scope. Requires strut removal and mount replacement (2.5-3 hours per side with alignment). Should always replace in pairs and get 4-wheel alignment after.

Estimated cost: $450-750