2000 BUICK CENTURY

Typical onset: 60,000-100,000 mi

Symptoms: Coolant loss with no visible external leaks, White smoke from exhaust on cold start, Milky oil on dipstick or oil cap, Overheating or erratic temperature gauge, Rough idle and misfires from coolant entering cylinders

Fix: Replace upper and lower intake manifold gaskets (use updated Fel-Pro or Mahle sets, NOT Dexcool-compatible OEM plastic gaskets). Flush cooling system completely, replace thermostat and coolant. Often requires new spark plugs/wires due to fouling. 6-8 hours labor. If caught late, may have damaged head gaskets or bearings from coolant contamination.

Estimated cost: $800-1,400

Typical onset: 80,000-120,000 mi

Symptoms: Persistent overheating even after intake gasket replacement, Combustion gases in cooling system (bubbling overflow tank), External coolant leaks from head mating surface, Loss of power and repeated misfires, Chocolate milk appearance in oil

Fix: Remove both heads, resurface or replace if warped, install updated composite head gaskets with ARP studs recommended. Replace all coolant system components (hoses, thermostat). Critical: address root cause (Dexcool and plastic gasket interaction). 12-16 hours labor. Often combined with timing chain replacement while you're in there.

Estimated cost: $1,800-2,800

Typical onset: 90,000-130,000 mi

Symptoms: Heavy knocking from bottom end, especially on cold start, Low oil pressure warning at idle when warm, Metallic debris in oil during changes, History of intake or head gasket leaks that weren't caught early

Fix: Once rod or main bearings are knocking, engine needs rebuild or replacement. Short block replacement is most cost-effective: 16-20 hours labor. Used engines are gamble (same issues). Remanufactured short block with updated gaskets is the right move if keeping the car.

Estimated cost: $2,500-4,500

Typical onset: 70,000-110,000 mi

Symptoms: Transmission fluid leaking near radiator area, Pink fluid dripping under front of vehicle, Low transmission fluid level without obvious external leak elsewhere, Transmission slipping or delayed engagement if driven low on fluid

Fix: Steel cooler lines rust through where they pass near frame rails and attach to radiator. Replace both lines (not just the leaking one—the other is next). If coolant mixed with ATF (internal radiator leak), you need radiator AND transmission flush/rebuild. Lines alone: 2-3 hours. With radiator: add 1.5 hours.

Estimated cost: $350-650 (lines only); $1,800-2,500 (if radiator contaminated trans)

Typical onset: 80,000-120,000 mi

Symptoms: Clunk when shifting from Park to Drive or Reverse, Excessive vibration at idle in Drive, Visible engine movement when revving in Park, Transmission shifter feels loose or notchy

Fix: The front transmission mount collapses, letting the powertrain rock excessively. Simple replacement but requires supporting the transmission. 1.5-2 hours labor. Use OEM or quality aftermarket (cheap mounts fail in 20k miles).

Estimated cost: $180-300

Typical onset: 100,000-150,000 mi

Symptoms: No-start with crank but no fire, Intermittent stalling at operating temperature, Whining noise from rear seat area, Inaccurate fuel gauge (stuck on empty or full), Hard start after sitting overnight

Fix: Fuel pump assembly in tank wears out. Entire assembly (pump, strainer, sending unit) should be replaced as a unit. Tank must be dropped. 3-4 hours labor. Common to find rust contamination in tank on older examples—inspect and clean or replace tank if corroded internally.

Estimated cost: $450-750

Symptoms: Power window falls into door or won't go up, Grinding or clicking noise when operating window, Window moves slowly or crookedly in track, Window works in one direction but not the other

Fix: Plastic regulator gears strip or cables fray. Front doors especially. Replace regulator assembly (motor usually fine). 1.5-2.5 hours per door depending on which one. Aftermarket regulators are hit-or-miss—budget for a redo if you cheap out.

Estimated cost: $250-400 per door