2002 MAZDA MX-5 MIATA

Typical onset: 60,000-120,000 mi

Symptoms: Blue smoke on startup or deceleration, Oil consumption exceeding 1 quart per 1,000 miles, Fouled spark plugs (especially #4 cylinder), Eventually: rod knock, spun bearings, catastrophic failure

Fix: Factory piston rings lose tension early. Proper fix requires full engine teardown, honing cylinders, installing upgraded rings (OEM or aftermarket low-tension), new bearings, gaskets. DIY-able for experienced builders; 18-24 labor hours at a shop. Many owners opt for used engine swaps (10-12 hours) or short-block replacements instead of rebuild.

Estimated cost: $3,500-6,500

Symptoms: Rough idle or vibration that worsens over time, Squealing from accessory belt area, Check engine light (crank position sensor codes), Pulley visibly wobbling if you look closely while running

Fix: The crank bolt can loosen due to inadequate factory torque or improper previous service. If caught early, retorque to 123 ft-lbs with engine locked (0.5 hours). If it's been loose for a while, the keyway gets wallowed out and you need crank nose repair or replacement crank (12-16 hours for crank R&R). Always use Loctite 271 on reinstall.

Estimated cost: $150-2,800

Typical onset: 80,000-150,000 mi

Symptoms: Clunking when shifting or letting off throttle, Excessive shifter vibration at idle, Difficulty getting into reverse or 1st gear, Visible tearing or separation of rubber mount

Fix: The rubber powertrain mount (PPF mount) deteriorates and tears. Replacement requires dropping the driveshaft and supporting transmission; 1.5-2 hours labor. Upgraded polyurethane mounts last longer but transmit more NVH. OEM rubber is fine for street use.

Estimated cost: $250-450

Typical onset: 100,000+ mi

Symptoms: Oil drips from bellhousing area, Oil spots under car after sitting, Clutch slipping if leak saturates friction surface (rare)

Fix: Seals age and harden. Requires transmission removal for access. While you're in there, replace both rear main and input shaft seals, plus clutch if it has miles on it. Transmission R&R is 4-5 hours; add clutch work if needed. Often done when clutch is already due.

Estimated cost: $600-1,200

Typical onset: 70,000+ mi

Symptoms: Oil seepage on back of engine (passenger side), Burning oil smell from exhaust manifold heat, Oil residue around spark plug tubes

Fix: Rubber valve cover gasket and CAS O-ring harden with heat cycles. Straightforward job: remove coil packs, valve cover, clean surfaces, install new gasket and O-ring. 1.5-2 hours. Use Mazda OEM gasket; aftermarket versions often leak prematurely.

Estimated cost: $200-350

Symptoms: Transmission fluid dripping near front crossmember, Low fluid level on dipstick (5-speed; 6-speed has no dipstick), Hard shifting when fluid runs low

Fix: Steel lines rust at fittings or crimp points, or aftermarket coolers develop pinhole leaks. Inspect lines annually in rust-belt states. Replacement lines or cooler install takes 1-2 hours. Flush and refill with proper GL-4 gear oil afterward.

Estimated cost: $300-600