2000 FORD F-150

Typical onset: 120,000-180,000 mi

Symptoms: Harsh or delayed 2-3 shift, especially under load, Slipping in overdrive or won't engage 4th gear, Transmission overheating, burnt fluid smell, Erratic shifts when cold, smooths out when warm

Fix: Rebuild or replacement needed. The 4R100 (behind 5.4L) has weak forward clutch packs and overdrive band. Rebuild takes 12-16 hours including R&R, fluid, converter. Many shops recommend replacement with remanufactured unit.

Estimated cost: $2,200-3,800

Typical onset: 80,000-150,000 mi

Symptoms: Misfires on one or more cylinders, rough idle, Spark plug blows out of cylinder head (loud pop, power loss), Plugs break off during removal, leaving threads in head, Check engine light with P030X misfire codes

Fix: The 2-valve 5.4L has short spark plug threads that strip or allow blowout. If blown out, requires HeliCoil or TimeSert thread repair (3-4 hours per hole). Broken plugs need extractor tools, can take 6-10 hours if multiple seize. Prevention: replace plugs at 60k-80k when warm, use anti-seize sparingly.

Estimated cost: $800-2,500

Typical onset: 100,000-160,000 mi

Symptoms: Whining or howling from rear end under acceleration, Clunking when shifting into drive or reverse, Gear oil leaking from pinion seal or axle tube seals, Vibration at highway speeds

Fix: Ford 8.8" and 9.75" rear ends are generally solid, but pinion bearings wear and axle seals leak. Simple seal replacement is 2-3 hours. Full ring-and-pinion or bearing overhaul is 6-8 hours plus setup time. Limited-slip clutch packs also wear out, causing one-wheel-peel.

Estimated cost: $400-1,800

Typical onset: 100,000-180,000 mi

Symptoms: No-start or extended cranking, especially when hot, Engine dies at idle or under load after running fine, Whining noise from fuel tank, Loss of power, hesitation under acceleration

Fix: In-tank fuel pump failures are common on these. Tank must be dropped (2-3 hours labor). Also see rusty fuel tank straps breaking. Fuel filter clogs if maintenance neglected—it's under the frame rail, easy 0.5 hour job but often forgotten.

Estimated cost: $600-1,100

Typical onset: 90,000-140,000 mi

Symptoms: Coolant leaks at front of engine, visible under intake, Rough idle, vacuum leaks, whistling under hood, Coolant in oil or oil in coolant (intake gasket failure), Engine runs rich, poor fuel economy

Fix: Plastic intake manifolds crack, and the coolant crossover passages leak. Gaskets fail between manifold and heads. Replacement is 4-6 hours on the 5.4L, slightly less on 4.6L. Aftermarket aluminum manifolds available and recommended. PCV valve and hoses also rot, causing vacuum leaks.

Estimated cost: $700-1,400

Typical onset: 80,000-130,000 mi

Symptoms: Clunking or popping over bumps from front end, Wandering or loose steering feel, Uneven tire wear on inside or outside edges, Play in wheel when jacked up, checked at 12 and 6 o'clock

Fix: Upper and lower ball joints wear, especially on 4x4 models. Uppers can be pressed or use aftermarket bolt-in replacements (2 hours per side). Lowers require more disassembly, 3-4 hours per side. Control arm bushings also wear. Alignment required after.

Estimated cost: $600-1,400

Typical onset: 120,000+ mi

Symptoms: AC blows warm, won't hold refrigerant charge, Oily residue on passenger floor or under dash, Refrigerant smell in cabin, Dye test shows leak behind dash

Fix: Evaporator is buried behind the entire dash assembly. Removal requires 8-12 hours labor—dash has to come out completely. Parts are cheap ($150-250), but labor kills you. Many owners live without AC rather than pay for this.

Estimated cost: $1,200-2,200

Symptoms: Cruise control won't set or engage, Cruise disengages randomly while driving, Brake pedal feels sticky or doesn't return fully, Recall-related: potential for stuck throttle (rare but serious)

Fix: Speed control deactivation switch at brake pedal fails or sticks. There was a recall for potential throttle sticking. Cable-actuated throttle on these trucks also sees frayed or binding cables. Switch replacement is 0.5 hours, throttle cable is 1-2 hours.

Estimated cost: $150-400