2004 MAZDA B4000

Typical onset: 100,000-150,000 mi

Symptoms: Rattling noise from front of engine on cold start that goes away after a few seconds, Check engine light with cam/crank correlation codes (P0340, P0345), Sudden catastrophic failure: engine quits, won't restart, bent valves

Fix: The plastic timing chain cassettes (guides) disintegrate, chain jumps time and valves hit pistons. If caught early: timing set replacement is 8-10 hours labor. If grenaded: short block or used engine replacement, 16-20 hours labor plus machine work if keeping heads.

Estimated cost: $1,800-3,200 preventive replacement; $4,500-7,000 post-failure rebuild

Typical onset: 80,000-130,000 mi

Symptoms: Pink milkshake in coolant overflow tank or radiator, Transmission slipping, delayed engagement, or no movement, Coolant in transmission pan during service, Transmission overheating

Fix: Steel cooler lines rust through at radiator connections or the internal radiator cooler fails, mixing ATF and coolant. Once mixed, transmission is typically toast. Requires new radiator, cooler lines, external cooler install, transmission rebuild or replacement, full coolant and ATF flush. 12-16 hours labor total.

Estimated cost: $3,500-5,500 with transmission rebuild

Typical onset: 90,000-140,000 mi

Symptoms: Coolant loss with no external puddles, White smoke from exhaust on startup, Rough idle or misfire when cold, Coolant in oil (milky dipstick) in severe cases

Fix: Plastic lower intake manifold cracks or gaskets fail, leaking coolant into cylinders or oil passages. Requires upper and lower manifold removal, new gaskets, often thermostat housing while you're in there. 6-8 hours labor.

Estimated cost: $900-1,500

Typical onset: 70,000-110,000 mi

Symptoms: Clunk when shifting from Park to Drive or Reverse, Vibration at idle in gear, Visible sag or tear in rubber mount under transmission

Fix: Rubber transmission crossmember mount deteriorates. Replacement is straightforward: support transmission, remove four bolts, swap mount. 1-1.5 hours labor. Do both engine mounts at same time if they're original.

Estimated cost: $200-350 for transmission mount only

Typical onset: varies by climate, typically 100,000+ mi

Symptoms: Brake fluid leak at rear wheels, Soft brake pedal, Parking brake doesn't hold, Rust perforation visible on steel brake lines along frame

Fix: Rear drum brake wheel cylinders seize or leak, and steel brake lines rust through in salt-belt states. Wheel cylinders: 2 hours labor. Full brake line replacement from master to rear axle: 6-8 hours. Often need hardware kits and shoes while you're in there.

Estimated cost: $350-600 wheel cylinders and shoes; $1,200-1,800 full brake line replacement

Typical onset: 80,000-120,000 mi

Symptoms: Clunking over bumps from front end, Wandering or loose steering feel, Tire wear on inner or outer edges, Visible play when prying on suspension

Fix: Upper and lower ball joints wear, especially in 4WD models. Lowers are pressed into control arms (3-4 hours labor per side with alignment). Uppers are riveted or bolted (2 hours per side). Always do alignment after. Suspension work on these is labor-intensive.

Estimated cost: $800-1,400 for both sides with alignment

Typical onset: 110,000-160,000 mi

Symptoms: No-start with crank but no fire, Stalling when hot or under load, Whining noise from fuel tank, Low fuel pressure (should be 60 psi)

Fix: In-tank electric fuel pump motor wears out. Requires dropping fuel tank (easier with truck on lift), replacing pump module. 3-4 hours labor. Use OE-quality pump; cheap ones fail quickly.

Estimated cost: $600-900