2002 BUICK CENTURY

Typical onset: 60,000-100,000 mi

Symptoms: External coolant leaks at front of engine, often driver side, White smoke from exhaust on cold start, Milky oil on dipstick or cap, Overheating with no obvious leak, Rough idle or misfire from coolant in cylinders

Fix: Replace plastic lower intake gasket set with updated aluminum-backed design; flush contaminated oil; pressure-test cooling system. Job requires upper plenum removal, fuel rail out, throttle body off. 4-6 hours labor for experienced tech, longer if coolant contaminated bearings. If caught late, coolant in oil destroys bearings and requires complete engine rebuild or replacement.

Estimated cost: $600-1,200 if caught early; $2,500-4,500 for short block if bearings damaged

Typical onset: 80,000-140,000 mi

Symptoms: External coolant seepage from head/block mating surface, Persistent overheating, Coolant loss with no visible leak, White exhaust smoke, Combustion gases in coolant (bubbling reservoir)

Fix: Both heads off, resurface if warped (common), new gaskets, new head bolts, coolant flush. Intake gaskets also done at same time since engine is apart. 8-12 hours labor. Often discovered after intake gaskets were ignored too long.

Estimated cost: $1,800-3,200

Typical onset: 90,000-150,000 mi

Symptoms: ATF puddle under engine bay, passenger side front, Burnt smell or low ATF level, Harsh shifting or slipping if level drops significantly

Fix: Steel cooler lines rust through where they pass near subframe or at radiator connections. Replace both lines as a pair with pre-bent OEM or aftermarket set. 2-3 hours labor, requires lifting vehicle and wrestling lines through tight spaces. Flush cooler in radiator if debris suspected.

Estimated cost: $350-650

Typical onset: 70,000-120,000 mi

Symptoms: Clunk or thud on hard acceleration or when shifting into reverse, Excessive engine movement visible from driver seat, Vibration at idle in Drive

Fix: Hydraulic front transmission mount fails internally. Jack engine slightly, unbolt mount, replace. 1 hour labor, straightforward.

Estimated cost: $150-280

Typical onset: 100,000-150,000 mi

Symptoms: Grinding or squealing from serpentine belt area, Battery light intermittent or steady, Electrical accessories dimming, Dead battery after short drives

Fix: Valeo alternators common on these; bearings seize or rotor rubs stator. Replace alternator, inspect belt and tensioner. 1.5 hours labor, straightforward top-side access.

Estimated cost: $300-550

Typical onset: 80,000-130,000 mi

Symptoms: Power steering fluid spray under hood, Whining or groaning on turns, Heavy steering effort, Burning smell from fluid on exhaust

Fix: High-pressure hose from pump to rack develops pinhole leaks or splits at crimps. Replace hose, flush system, bleed air. 1.5 hours labor.

Estimated cost: $200-400

Symptoms: Check Engine light with P0440-range EVAP codes, Fuel tank hissing when cap removed, Difficulty fueling (pump clicks off repeatedly), Fuel smell near tank

Fix: Vent valve on top of tank or rollover valve fails; sometimes tank itself cracks near filler neck. NHTSA recall addressed some tanks but not all failures. Tank drop required for inspection/replacement. 2-3 hours labor for vent valve; 4-5 hours if tank replacement needed.

Estimated cost: $250-450 for vent valve; $600-1,000 for tank