1978 OLDSMOBILE 98

Typical onset: 40,000-80,000 mi

Symptoms: Hard starting when warm, White smoke from exhaust indicating coolant intrusion, Rapid coolant loss with no external leaks, Sudden loss of power and seized engine

Fix: The 350 diesel used gasoline engine block architecture with inadequate head bolt torque and head gasket design. Leads to head gasket failure, cracked heads, or complete block failure. Most require engine replacement or conversion to gas V8. Labor: 18-24 hours for swap.

Estimated cost: $3,500-6,500

Typical onset: 80,000-120,000 mi

Symptoms: Rattling noise from front of engine on cold startup that disappears when warm, Rough idle and loss of power, Check engine light or missing/backfiring, Sudden no-start condition if chain jumps or breaks

Fix: Olds V8s use fiber/nylon cam gear teeth that disintegrate with age and heat. Stretched timing chains common. Requires front cover removal, new metal timing gear set, chain, and tensioner. Labor: 6-8 hours.

Estimated cost: $800-1,400

Typical onset: 100,000-150,000 mi

Symptoms: Delayed engagement from park to drive, Slipping between 1st and 2nd gear, Burnt transmission fluid smell, No movement in any gear

Fix: These transmissions are generally robust but suffer from worn clutch packs and seals at high mileage, especially if fluid wasn't changed every 30K. Rebuild includes all clutches, bands, seals, and torque converter. Labor: 8-12 hours.

Estimated cost: $1,800-2,800

Typical onset: 70,000-130,000 mi

Symptoms: Oil puddle under rear of engine after sitting overnight, Oil coating on transmission bellhousing, Burning oil smell from exhaust heat, Low oil level between changes

Fix: The rope-style rear main seal hardens and leaks with age. Requires transmission removal to access. Often done during transmission work. Labor: 6-8 hours standalone, 2-3 hours added to trans R&R.

Estimated cost: $600-1,200

Typical onset: 60,000+ mi

Symptoms: Whining noise during turns, especially when cold, Power steering fluid puddles under front of car, Heavy steering effort intermittently, Low fluid reservoir requiring constant top-offs

Fix: Saginaw pumps develop seal leaks, and steering boxes leak from sector shaft seals. Pump replacement is straightforward. Steering box rebuild or replacement more involved. Pump labor: 2-3 hours. Box: 4-6 hours.

Estimated cost: $350-900

Symptoms: Rough idle and stalling when cold, Excessive fuel consumption, Hesitation on acceleration, Gas smell and flooding, Black smoke from exhaust

Fix: The Quadrajet is complex but rebuildable. Common issues: worn throttle shafts causing vacuum leaks, deteriorated float causing flooding, stuck choke. Full rebuild with quality kit. Labor: 3-5 hours including removal and tuning.

Estimated cost: $400-750

Typical onset: 70,000-110,000 mi

Symptoms: Clunking noise over bumps, Wandering steering or play in wheel, Uneven tire wear on inside edges, Vehicle pulls to one side

Fix: Heavy B-body cars eat ball joints and idler arms. Lower ball joints typically wear first. Should replace upper and lower together, plus idler arm. Requires alignment after. Labor: 4-6 hours for both sides plus idler.

Estimated cost: $600-1,100

Symptoms: Visible rust bubbling on lower fenders and doors, Trunk floor rust-through, Frame rust on rear trailing arms mounts, Rocker panel perforation

Fix: Northern cars suffer from typical GM rust issues in rocker panels, lower fenders, and trunk floors. Frame rust at rear spring mounts can be structural concern. Repairs range from patch panels to full frame section replacement. Labor: highly variable, 10-40+ hours.

Estimated cost: $1,500-6,000