1986 BUICK SKYHAWK

Typical onset: 80,000-140,000 mi

Symptoms: Severe rod knock or main bearing rumble on cold starts, Oil pressure drops below 10 psi at idle when warmed up, Metal flakes or glitter in oil filter and pan, Sudden loss of power followed by seizure

Fix: These 1.8L and 2.0L engines suffer from marginal oil delivery and thin bearing journals. Typical fix is short block replacement (pistons, crank, bearings) or a junkyard long block swap. Budget 16-20 hours for R&R plus machine work if rebuilding. Many owners just swap in a used engine due to core availability.

Estimated cost: $1,800-3,500

Typical onset: 70,000-110,000 mi

Symptoms: Transmission fluid mixing with coolant (strawberry milkshake in radiator), Transmission slipping or delayed engagement after cooler contamination, Rust-colored coolant or oily film in overflow tank, External leaks at cooler line fittings near radiator

Fix: The THM125C three-speed automatic routes fluid through a cooler in the radiator's side tank. Steel lines rot, and internal cooler fails, cross-contaminating fluids. Requires radiator removal or replacement, new cooler lines, complete transmission flush (sometimes replacement if contaminated), and fresh fluid. Labor runs 6-10 hours depending on transmission condition. Many techs recommend external auxiliary cooler to prevent repeat.

Estimated cost: $800-2,200

Typical onset: 60,000-100,000 mi

Symptoms: Heavy clunking when shifting from Park to Drive or Reverse, Excessive engine rocking visible from driver's seat during acceleration, Vibration through floorboards at idle, smooths out at higher RPM, Transmission linkage feels notchy or binds

Fix: The front and rear engine mounts, plus the transmission mount, are hydraulic-filled and fail from age and heat. When they collapse, the powertrain moves excessively and stresses linkages. Replace all three mounts as a set—doing one at a time leads to rapid failure of the others. Labor is about 3-4 hours total.

Estimated cost: $350-650

Typical onset: 90,000-130,000 mi

Symptoms: Blue smoke on deceleration or startup after sitting, Burning through a quart of oil every 500-800 miles, Fouled spark plugs (oil-soaked electrode), Loss of compression on multiple cylinders (under 100 psi)

Fix: Ring land carbon buildup and worn oil control rings plague these engines, especially if maintenance was neglected. Fix requires cylinder honing and new piston rings, or a full rebuild. Most shops pull the engine for access—figure 18-24 hours labor for a ring job with head work. If cylinders are scored, it's short-block time.

Estimated cost: $1,400-2,800

Symptoms: Intermittent stalling or hesitation under load, especially uphill, Hard starting after sitting overnight, Loss of power at highway speeds, improves after coasting, Fuel pump whine increases as filter restricts flow

Fix: The inline fuel filter clogs from rust and varnish in the steel tank—common if the car sat or used old fuel. Filter replacement is 30 minutes, but recurring clogs signal tank contamination. Expect to drop and clean the tank or replace the pump sock if the problem returns. Filter swap alone is cheap; tank service adds 4-6 hours.

Estimated cost: $80-600

Symptoms: High idle (1,200+ RPM) or surging idle that won't settle, Stalling when coming to a stop after highway driving, Difficulty adjusting idle speed screw with any effect, Black soot around carb base or intake gasket

Fix: The Rochester 2SE two-barrel on the 1.8L has tiny idle air bleeds that clog with fuel varnish. Cleaning requires carb removal, full disassembly, and soaking. Budget 3-4 hours for a thorough rebuild with gaskets. Many techs swap in a reman unit if internal passages are corroded. The 2.0L TBI is more reliable but still sees injector clogging.

Estimated cost: $250-550