1987 BUICK SKYLARK

Typical onset: 80,000-120,000 mi

Symptoms: Delayed or harsh 1-2 shift, especially when cold, Slipping in 2nd or 3rd gear under load, Metal shavings in pan during fluid service, Sudden loss of forward gears, reverse only

Fix: Rebuild or replacement required; internal clutch packs and bands wear prematurely. Cooler lines often corrode causing fluid contamination. Plan 8-12 labor hours for removal, rebuild, and reinstall. Used units are plentiful but condition varies wildly.

Estimated cost: $1,200-2,200

Typical onset: 120,000-180,000 mi

Symptoms: Heavy knocking from crankcase, especially on cold start, Oil pressure drops below 10 psi at idle when warm, Metallic debris on oil drain plug magnet, Sudden catastrophic failure with rod through block

Fix: Main and rod bearings wear due to marginal oiling system and extended service intervals. Requires engine removal, full teardown, crank polishing or replacement, and new bearings. Machine work adds 2-3 days. Total 18-25 labor hours if salvageable; many opt for junkyard long block swap instead.

Estimated cost: $1,800-3,500

Typical onset: 90,000-140,000 mi

Symptoms: Consuming 1 quart per 500-800 miles, Blue smoke on deceleration or startup, Fouled spark plugs, repeated misfires, Loss of compression in one or more cylinders

Fix: Iron Duke ring lands crack or carbon-pack from heat and poor-quality oil. Requires head removal, hone, new rings, and ideally pistons. Budget 12-16 hours. Often discovered during diagnosis for high oil consumption; many owners just keep adding oil until something else breaks.

Estimated cost: $1,400-2,400

Typical onset: 60,000-100,000 mi

Symptoms: Severe clunking when shifting from Park to Drive or Reverse, Vibration through shifter and floor at idle, Visible engine/trans lean toward passenger side, Difficulty engaging gears

Fix: Hydraulic transmission mount deteriorates and allows excessive drivetrain movement. Simple bolt-in replacement but access is tight on passenger side; 1.5-2.5 hours. Often done alongside engine mounts for best results.

Estimated cost: $180-320

Symptoms: Hard starting after sitting overnight, Stumbling or stalling during acceleration, Rough idle, surging at highway speed, Check engine light with lean codes

Fix: TBI systems gum up from ethanol fuel and sitting. Fuel filter (inline near tank) clogs from rust and varnish. Replace filter every 30k miles whether needed or not; injector cleaning often required. Filter replacement is 0.5 hours, injector service adds 1-2 hours.

Estimated cost: $120-280

Typical onset: 80,000-130,000 mi

Symptoms: ATF puddle under front of vehicle, Transmission overheating, burnt fluid smell, Sudden loss of all gears after fluid loss, Visible rust perforation on steel cooler lines

Fix: Steel cooler lines rust through where they contact subframe or behind splash shields. Loss of fluid kills transmission rapidly. Replacement lines require trans and radiator work; 2-4 hours depending on which line fails. Flush system and inspect cooler for blockage.

Estimated cost: $220-450

Typical onset: 70,000-110,000 mi

Symptoms: Coolant loss with no visible external leak, White smoke from exhaust on startup, Rough idle, misfires on one bank, Coolant in oil (milky dipstick)

Fix: The 3.0L Buick V6 uses composite intake gaskets that fail and allow coolant into cylinders or oil passages. Requires intake removal, gasket set, and coolant flush. Often find corroded throttle body during disassembly. 4-6 hours labor.

Estimated cost: $450-750