1997 PONTIAC BONNEVILLE

Typical onset: 80,000-140,000 mi

Symptoms: Sudden loss of power under acceleration, Whining or grinding noise from front of engine, Check engine light with MAF sensor codes, Boost gauge reads zero

Fix: Replace rubber coupler between supercharger snout and input shaft, sometimes requires front cover removal if snout seal also leaking. 3-5 hours labor depending on technician experience.

Estimated cost: $400-800

Typical onset: 60,000-120,000 mi

Symptoms: Milky tan sludge on oil cap and dipstick, White exhaust smoke on cold start, Rapid coolant loss with no external leaks, Engine overheating and potential bearing damage if driven

Fix: Replace lower intake manifold gaskets (Fel-Pro or Felpro PermaDryPlus kit recommended), flush cooling system, change oil 3 times over 500 miles to clear contamination. If driven with coolant in oil, often requires bearing replacement. 6-8 hours labor for gaskets alone, 30-40 hours if bearings damaged.

Estimated cost: $800-1,200 (gaskets only), $3,500-6,000 (if bearings damaged)

Typical onset: 70,000-150,000 mi

Symptoms: Transmission fluid in coolant overflow (pink milkshake appearance), Transmission slipping or delayed engagement, Sudden transmission failure after coolant contamination, Coolant in transmission pan

Fix: Replace transmission cooler lines and radiator (internal cooler failure contaminates trans fluid). Flush transmission and torque converter multiple times, replace filter. If coolant circulated through transmission, rebuild often required. 8-10 hours for lines/radiator/flush, add 20-25 hours for transmission rebuild.

Estimated cost: $1,200-1,800 (preventive), $2,800-4,500 (if transmission damaged)

Typical onset: 100,000-180,000 mi

Symptoms: Knocking or rattling from bottom end at idle, Low oil pressure warning at idle when hot, Metallic debris in oil filter, Sudden catastrophic failure with no warning

Fix: Usually rod bearings fail first from oil starvation or extended oil change intervals. Requires engine disassembly, crankshaft inspection/machining, new bearings, often new oil pump. Many shops recommend short block replacement instead. 25-35 hours labor for in-chassis rebuild.

Estimated cost: $3,000-5,500 (rebuild), $4,500-7,000 (short block swap)

Typical onset: 80,000-150,000 mi

Symptoms: Clunking on acceleration or deceleration, Engine rocks excessively when shifting to drive/reverse, Vibration through steering wheel at idle, Supercharger belt misalignment and squealing

Fix: Replace upper torque strut (dogbone mount) and front engine mount. Both wear from torque of supercharged engine. 2-3 hours labor for both mounts.

Estimated cost: $350-600

Typical onset: 100,000-180,000 mi

Symptoms: No start or extended crank time when hot, Stalling at idle after highway driving, Fuel gauge reads empty or erratic, Loss of power under load

Fix: Replace fuel pump module assembly, requires dropping fuel tank. Common for pump to fail intermittently when hot due to worn brushes. 3-4 hours labor.

Estimated cost: $500-850

Symptoms: ABS light stays on constantly, Brake pedal pulsation during normal stops, Extended stopping distances, Pump runs continuously or cycles when parked

Fix: Replace entire ABS modulator assembly, bleed system. GM Teves Mark IV system notorious for valve body failures. 2-3 hours labor.

Estimated cost: $800-1,400