2000 MAZDA MX-5 MIATA

Typical onset: 80,000-150,000 mi

Symptoms: sudden loss of power, rough idle or no-start after the key shears, timing off despite good belt condition, metallic noise from front of engine

Fix: The Woodruff key that locates the crank pulley can shear, letting the pulley spin freely and destroying timing. Requires crank removal, keyway repair or replacement crank, often short block if debris circulated. 15-25 hours labor for short block swap.

Estimated cost: $3,500-6,000

Typical onset: 60,000-100,000 mi

Symptoms: clunking on shifts, especially 1st to 2nd, excessive shifter vibration, visible sag or torn rubber on PPF mount, driveline lash on throttle tip-in

Fix: The power plant frame (PPF) mount deteriorates and causes driveline slop. Aftermarket mounts are stiffer and last longer. 1.5-2 hours labor for PPF mount replacement.

Estimated cost: $200-400

Typical onset: 70,000-120,000 mi

Symptoms: oil seeping from back of valve cover onto firewall, rough idle or stalling when hot, check engine light with cam/crank correlation codes, oil smell in cabin with heat on

Fix: The CAS at the rear of the head uses an O-ring that hardens and leaks. Easy fix but requires intake manifold removal for access. 2-3 hours labor, replace O-ring and reseal.

Estimated cost: $250-450

Typical onset: 100,000-150,000 mi

Symptoms: oil spots under the bell housing area, clutch contamination causing slip or chatter, visible wetness between engine and transmission, oil consumption without external leaks elsewhere

Fix: Rear main seal weeps and can soak the clutch. Requires transmission removal. Often done during clutch jobs. 6-8 hours labor if doing seal only, add 2 hours if bundling with clutch.

Estimated cost: $800-1,200

Symptoms: harmonic squealing or wobble at idle, vibration felt through chassis, pulley visibly off-center or wobbling, check engine light with crank position codes

Fix: Early 1.8L short-nose cranks can have the main pulley bolt back out if not properly torqued or if Loctite fails. Catch it early: retorque with Loctite and fresh bolt. If it wobbles too long, keyway damage occurs—see crank failure above. Preventive retorque: 1 hour labor.

Estimated cost: $100-200

Typical onset: 80,000-130,000 mi

Symptoms: oil pooling in spark plug wells, burning oil smell, ignition misfire on one or more cylinders, oil weeping down side of engine

Fix: Gasket and tube seals harden over time. Straightforward job: replace gasket, tube seals, and half-moon seals. 2-3 hours labor.

Estimated cost: $300-500

Typical onset: 90,000-140,000 mi

Symptoms: gear oil dripping near front crossmember, low transmission fluid causing hard shifts, visible wet lines running to small cooler behind bumper, burnt gear oil smell

Fix: Steel lines rust through or rubber sections crack. Replace lines and top off fluid. 1.5-2 hours labor, parts are inexpensive but fiddly to route.

Estimated cost: $200-350