1998 NISSAN SKYLINE

Typical onset: 80,000-150,000 mi

Symptoms: persistent ticking or tapping at idle that worsens when hot, noise from valve cover area especially on cold start, occasional Check Engine Light for camshaft position sensor correlation

Fix: RB25 hydraulic lifters wear and collapse, requiring full lifter replacement (all 12). Job requires valve cover removal, cam removal, and shim adjustment. Expect 6-8 hours labor. Often combined with cam tower reseal and valve cover gasket since you're in there.

Estimated cost: $800-1,500

Typical onset: 100,000-180,000 mi

Symptoms: white smoke from exhaust on startup, coolant loss with no visible leaks, milky oil on dipstick or cap, overheating under boost or sustained load

Fix: RB25DET head gaskets fail between cylinders or into coolant passages, especially if previously overheated or overboost. Requires head removal, surface check (often needs machine work), ARP studs recommended. 12-16 hours labor, plus machine shop time if warped. Always replace timing components and water pump while apart.

Estimated cost: $2,500-4,200

Typical onset: 90,000-140,000 mi

Symptoms: blue smoke under acceleration or at idle after decel, whistling or grinding noise from turbo area, loss of boost pressure above 10 psi, oil pooling in intercooler piping

Fix: Factory ceramic-wheel turbos wear bearings and seals. Rebuilds often fail quickly—replacement with modern ball-bearing unit is better long-term. Turbo swap is 4-6 hours including gaskets and oil feed/return lines. Verify no shaft play before buying any used Skyline.

Estimated cost: $1,200-2,800

Typical onset: null

Symptoms: transmission slipping or delayed engagement, milky pink fluid in radiator overflow, transmission overheating warnings, coolant contamination in trans fluid

Fix: Factory transmission cooler integrated into radiator fails internally, cross-contaminating coolant and ATF. Requires radiator replacement, full trans fluid flush (multiple fills), and often external cooler addition. If caught early, trans survives; if run contaminated, expect internal damage. 3-5 hours labor for cooler and flush, add 15-25 hours if trans needs rebuild.

Estimated cost: $600-1,200 (cooler/flush), $3,500-5,500 (if trans damaged)

Typical onset: 120,000-200,000 mi

Symptoms: vibration at idle that smooths above 2,000 rpm, visible rubber separation or wobble on crank pulley, serpentine belt wear or tracking issues, timing marks no longer aligned

Fix: RB25 harmonic balancer rubber deteriorates, causing imbalance and potential timing issue if keyway damages. Replacement is straightforward but requires crank bolt removal (impact gun, 203 ft-lb retorque). 2-3 hours labor. Inspect carefully on purchase—failed balancers can grenade and take out front cover.

Estimated cost: $400-700

Typical onset: null

Symptoms: stumbling or lean surging under boost, fuel pump priming loudly or whining, lean AFR readings past 12 psi, hard start after sitting overnight

Fix: Imported cars often sat with old fuel in Japan, leaving varnish and rust in tank. Fuel filter clogs quickly (some owners report 3-6 month intervals). Start with filter replacement (1 hour labor), but chronic issues require tank drop, clean, and pump/sock replacement. Pre-filter addition helps long-term.

Estimated cost: $150-300 (filter), $800-1,400 (full fuel system service)

Typical onset: 70,000-130,000 mi

Symptoms: clunking on 1-2 shift or throttle tip-in, excessive driveline vibration at idle in gear, visible transmission sag when inspected from below

Fix: Rubber transmission mount deteriorates, allowing excess movement and driveline shock. Replacement requires trans support and mount swap from below. 1.5-2 hours labor. Nismo or polyurethane mounts reduce future failures but add NVH.

Estimated cost: $250-500