1998 ASTON MARTIN DB7

Typical onset: 60,000-100,000 mi

Symptoms: excessive oil consumption (quart per 500-1000 miles), cold-start smoking that clears after warmup, loss of compression in one or more cylinders, rough idle and misfires

Fix: The Nikasil-lined bores react badly to high-sulfur fuel (pre-2000s issue). Requires complete engine-out rebuild with steel liner sleeves, new pistons, rings, bearings. 60-80 labor hours at specialist shop. Many owners opt for short-block replacement instead of sleeving.

Estimated cost: $15,000-25,000

Typical onset: 80,000-120,000 mi

Symptoms: deep knocking noise from lower engine, especially under load, metallic rattling at idle, sudden loss of oil pressure, metal shavings in oil filter and pan

Fix: Often results from extended oil change intervals or running low on oil. Supercharged AJ16 is hard on bearings. Engine-out rebuild required: new mains, rods, crank polishing or replacement. Typically discovered during Nikasil repair or after catastrophic failure. 50-70 labor hours.

Estimated cost: $12,000-18,000

Typical onset: 70,000-110,000 mi

Symptoms: transmission fluid leaking onto exhaust manifold (burning smell), slipping or delayed engagement when hot, pink fluid puddles under car, transmission overheating warnings if equipped

Fix: The ZF 4HP24 transmission cooler lines crack at fittings, and rubber transmission mounts collapse causing movement and line stress. Replace cooler lines, external cooler, and all three mounts as a set. 6-9 labor hours.

Estimated cost: $1,800-3,200

Typical onset: 50,000-90,000 mi

Symptoms: squealing on cold starts or acceleration, intermittent boost loss (feels sluggish), visible belt wobble, tensioner arm movement or bouncing

Fix: Eaton M90 supercharger belt system uses automatic tensioner that wears out. Idler pulley bearings also fail. Replace tensioner assembly, idler pulley, and belt together. Access is tight. 4-6 labor hours.

Estimated cost: $800-1,400

Typical onset: 60,000-100,000 mi

Symptoms: rapid overheating, coolant loss with no visible external leak (cracked header tank), burst upper radiator hose, coolant weeping from thermostat housing

Fix: Plastic radiator end tanks crack, 25-year-old hoses burst under pressure, and plastic thermostat housing cracks. This engine does NOT tolerate overheating—leads directly to head gasket failure or worse. Replace entire cooling system preventively: radiator, all hoses, thermostat housing, water pump, expansion tank. 8-12 labor hours.

Estimated cost: $2,500-4,000

Typical onset: 80,000-130,000 mi

Symptoms: white smoke from exhaust, coolant in oil (milky dipstick), bubbling in overflow tank, mysterious coolant loss, rough running and misfires

Fix: Usually follows overheating event or is age-related. Inline-six layout means head-off job is straightforward but labor-intensive. Send heads out for pressure testing and resurfacing. Replace head bolts (torque-to-yield). 18-24 labor hours for both banks.

Estimated cost: $4,500-7,000

Typical onset: 70,000-120,000 mi

Symptoms: extended cranking before start, hesitation or stumble under hard acceleration, rough idle when hot, fuel smell in cabin or trunk area

Fix: In-tank pump weakens, inline filter clogs (often neglected—should be changed every 30k), and fuel pressure regulator diaphragm leaks. Pump replacement requires tank drop. Do pump, filter, and regulator together. 5-8 labor hours.

Estimated cost: $1,200-2,200