The 1998 DB7 with its supercharged 3.2L inline-six (basically a modified Jaguar AJ16) is a beautiful GT car with predictable weak points: cooling system failures, transmission issues, and catastrophic engine bearing problems if oil service history is sketchy. Parts availability and specialist labor make ownership expensive.
Nikasil Cylinder Bore Liner Failure Leading to Engine Rebuild
Occasional · high severityTypical 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
Crankshaft Main and Rod Bearing Failure
Occasional · high severityTypical 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
Automatic Transmission Oil Cooler Line and Mount Failures
Common · medium severityTypical 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
Supercharger Drive Belt Tensioner and Pulley Failure
Common · medium severityTypical 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
Cooling System Catastrophic Failure (Radiator, Hoses, Thermostat Housing)
Common · high severityTypical 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
Head Gasket Failure (Both Banks)
Occasional · high severityTypical 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
Fuel System Issues (Pump, Filter, Pressure Regulator)
Common · medium severityTypical 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
Buy only with documented service history and a pre-purchase inspection by a marque specialist; plan for $5-10k in deferred maintenance and keep a $15k engine-rebuild fund—gorgeous car, but ownership is expensive and unforgiving of neglect.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.