1990 MAZDA 626

Typical onset: 80,000-140,000 mi

Symptoms: White smoke from exhaust, Coolant loss with no visible leaks, Overheating under boost, Milky oil on dipstick, Rough idle and misfires

Fix: Head gasket job is 8-10 hours labor, but many engines are already damaged by the time symptoms appear—burned pistons, scored cylinder walls, spun bearings. If caught early, gasket replacement with ARP studs and machine work runs manageable. If ignored, you're looking at full rebuild or short block swap at 25-35 hours labor.

Estimated cost: $1,200-2,800 for gaskets alone; $3,500-6,500 for full rebuild with pistons, bearings, rings

Typical onset: 70,000-120,000 mi

Symptoms: Transmission fluid leaking near radiator, Overheating transmission, Erratic shifting, Pink milky fluid in coolant reservoir (cooler rupture into radiator)

Fix: Steel cooler lines rust through where they connect to radiator. If coolant mixes with ATF internally, both fluids are contaminated and transmission damage follows quickly. Replace lines (2-3 hours), flush both systems, possibly replace radiator if internal contamination occurred. Transmission rebuild if driven after contamination.

Estimated cost: $350-650 for lines and flush; $1,800-3,200 if transmission needs rebuild

Typical onset: 90,000-150,000 mi

Symptoms: Loss of power under acceleration, Boost spikes or no boost, Rattling from turbo at idle, Check engine light with lean/rich codes, Excessive black smoke

Fix: Wastegate actuators seize or diaphragms rupture, causing uncontrolled boost or no boost. Can lead to detonation and engine damage if spiking. Turbo rebuild or replacement is 6-8 hours including manifold removal, downpipe work, and oil line replacement.

Estimated cost: $800-1,600 depending on turbo condition and whether rebuild or replacement

Typical onset: 100,000-180,000 mi

Symptoms: Knocking noise from bottom end, especially on cold start, Low oil pressure at idle, Metal shavings in oil, Sudden catastrophic failure with rod through block

Fix: F2T engines prone to bearing wear from oil starvation during boost, especially if oil changes were neglected or turbo timer not used. Requires complete teardown, crank inspection/grinding, new bearings, possibly crank replacement. 20-30 hours labor for proper job.

Estimated cost: $2,500-4,500 with machine work; $800-1,200 if caught early and only bearings needed

Symptoms: Hard starting, Stumbling under boost, Loss of top-end power, Hesitation during acceleration, Stalling at idle after hard driving

Fix: These cars used old-formula fuel systems that gum up badly. In-tank pump screens clog, fuel filters plug early, injectors get varnished. Filter is 0.5 hour job but needs doing every 15k-20k miles on a 30+ year old car. Injector cleaning adds 2-3 hours.

Estimated cost: $80-150 for filter; $250-450 for injector service

Typical onset: 60,000-100,000 mi

Symptoms: Clunking when shifting, Excessive engine movement during acceleration, Vibration at idle in gear, Shifter feels loose or notchy

Fix: Rubber mounts deteriorate and transmission sags, causing driveline angles to change and axle seal leaks. Replace all three mounts (engine and transmission) together. 3-4 hours labor.

Estimated cost: $350-550