1999 INFINITI G20

Typical onset: 120,000-180,000 mi

Symptoms: Blue smoke on startup or acceleration, Burning through 1+ quart per 1,000 miles, Fouled spark plugs, Loss of power under load

Fix: SR20DE engines suffer from oil control ring land wear and carbon buildup. Requires engine teardown, new piston rings, ridge reaming, honing, and fresh valve seals. Budget 16-20 hours labor. Many shops recommend short-block replacement or used engine swap at this mileage due to cylinder bore wear.

Estimated cost: $2,800-4,500

Typical onset: 80,000-150,000 mi

Symptoms: No-start condition, Intermittent stalling when hot, Rough idle and misfires, Tachometer drops to zero while driving

Fix: Internal optical sensor or ignition module fails. Aftermarket units are hit-or-miss; OEM Nissan distributor is the reliable fix. 1.5 hours labor for removal and installation, plus timing verification.

Estimated cost: $450-750

Typical onset: 100,000-160,000 mi

Symptoms: ATF puddle under engine bay, Low transmission fluid warnings, Transmission slipping or delayed engagement, Fluid level drops between checks

Fix: Steel cooler lines rust through at the bend near the radiator. Replace both lines as a set; corroded fittings often require radiator removal for access. 3-4 hours labor including fluid refill and leak check.

Estimated cost: $400-650

Typical onset: 90,000-140,000 mi

Symptoms: Clunk on acceleration or deceleration, Excessive vibration at idle in gear, Shifter moves visibly under throttle, Harsh engagement into reverse

Fix: Hydraulic mounts deteriorate and separate. Replace front and rear mounts together; rear mount requires subframe support. 2.5-3 hours labor for both.

Estimated cost: $350-550

Typical onset: 80,000-130,000 mi

Symptoms: Clunking over bumps, Steering wander or vague feel, Inner tire edge wear, Play detected during suspension inspection

Fix: Ball joints are pressed into the lower control arms. Most techs replace the entire control arm assembly for reliability. 2 hours per side including alignment. Always do alignment after replacement.

Estimated cost: $500-800

Typical onset: 120,000+ mi

Symptoms: Hesitation under hard acceleration, Stalling after sustained highway driving, Hard starting when fuel tank below 1/4, Loss of power on hills

Fix: Fuel pump sock filter clogs with sediment; no external serviceable filter on this model. Requires fuel tank drop and pump assembly removal. Replace pump assembly or at minimum the strainer sock. 3-4 hours labor.

Estimated cost: $450-850

Typical onset: 70,000-120,000 mi

Symptoms: Oil residue on valve cover or distributor base, Burning oil smell from engine bay, Oil seepage visible during inspection, Spark plug tubes may fill with oil

Fix: Cork-rubber gaskets harden and shrink. Replace valve cover gasket, distributor O-ring, and spark plug tube seals together. Clean mating surfaces thoroughly. 2-2.5 hours labor.

Estimated cost: $280-450