2000 MAZDA B2500

Typical onset: 120,000-180,000 mi

Symptoms: White smoke from exhaust, milky oil on dipstick, Rapid coolant loss with no visible external leaks, Overheating episodes followed by rough idle or misfire, Metal shavings in oil, knocking noise after overheat event

Fix: Head gaskets fail, owner keeps driving, coolant enters cylinders and washes cylinder walls, destroys bearings. By the time it's diagnosed, you're looking at short block replacement or full rebuild: 18-25 labor hours depending on machine shop work needed. Many shops quote engine swap from salvage yard instead.

Estimated cost: $3,200-5,800

Typical onset: 90,000-140,000 mi

Symptoms: ATF puddle under front of truck, usually driver side, Transmission slipping or delayed engagement after leak starts, Pink fluid mixed in coolant overflow (cooler internal leak), Transmission overheating warning or burnt smell

Fix: Steel lines rust through at frame contact points, or radiator-mounted cooler develops internal leak contaminating both fluids. External line replacement is 1.5-2 hours, but if coolant entered trans or ATF entered cooling system, expect trans flush/rebuild and cooling system flush. Total labor can hit 8-12 hours with transmission work.

Estimated cost: $400-800 for lines only, $2,200-3,800 with trans rebuild

Typical onset: 150,000-200,000 mi

Symptoms: Excessive oil consumption, 1+ quart per 500-800 miles, Blue smoke on startup or acceleration, Low compression on one or more cylinders, Fouled spark plugs repeatedly

Fix: Rings stick or break from carbon buildup exacerbated by extended oil change intervals. If caught early you can sometimes get away with ring job (12-15 hours), but typically cylinders are scored requiring overbore or sleeves, pushing you into full rebuild territory. Most opt for used engine swap at this point.

Estimated cost: $2,800-4,200

Symptoms: Intermittent stalling at idle or under load, Hard starting when engine is hot, Sputtering during acceleration, Check engine light with lean codes (P0171/P0174)

Fix: In-line fuel filter clogs from rust in steel tank, starves engine. Should be replaced every 30k but often neglected. Filter replacement is 0.5 hour job, but diagnosis often takes longer because symptoms mimic MAF or pump failure. If tank is rusty inside, you're looking at tank drop and clean/replace: add 3-4 hours.

Estimated cost: $80-150 filter only, $500-750 with tank service

Typical onset: 80,000-130,000 mi

Symptoms: Clunk when shifting from Park to Drive or Reverse, Excessive vibration at idle in gear, Visible sag or torn rubber on mount, Transmission shifts feel harsh

Fix: Rubber mount on transmission crossmember tears from age and heat cycling. Common wear item. Replacement is straightforward: 1-1.5 hours to support trans, swap mount, reassemble. Often done with engine mounts at same time.

Estimated cost: $180-320

Typical onset: 140,000-190,000 mi

Symptoms: Knocking noise on cold start that may disappear when warm, Low oil pressure warning or gauge reading below 20 psi at idle, Metallic rattling under acceleration, Rod knock that worsens rapidly

Fix: Often follows minor overheating event or sludge buildup from neglect. Bearings spin, score crank journals. Requires crankshaft R&R, measure/polish or replace crank, new bearings, full bottom-end work: 16-22 hours. At this mileage and cost, most owners total the truck.

Estimated cost: $3,500-5,200