1968 PONTIAC 2+2

Typical onset: 80,000-150,000 mi cumulative or unknown history

Symptoms: Deep knocking from crankcase, worse under load or cold starts, Metallic debris in oil filter or pan, Sudden catastrophic loss of oil pressure, Visible crank endplay or wobble during inspection

Fix: Full teardown required—pull engine, split block, mic journals, regrind or replace crank if out-of-spec, install oversized bearings, replace oil pump. Budget 25-35 shop hours for R&R plus machine work. Many survivors have unknown maintenance history and original or badly-rebuilt bottom ends.

Estimated cost: $4,500-8,000

Symptoms: Clunk during throttle lift or gear engagement, Visible tailshaft droop, driveline angle looks wrong, Vibration at highway speed from poor U-joint angles, Shifter feels loose or misaligned

Fix: Rubber mounts harden and crumble after 50+ years; crossmember can sag from rust or stress cracks. Replace mount and inspect/reinforce crossmember. 2-3 hours labor if just the mount, add 4-6 if welding/fabrication needed.

Estimated cost: $250-900

Symptoms: Transmission fluid weeping or spraying from steel lines at radiator, Overheating transmission, burnt smell after highway runs, Pink or milky fluid if internal radiator cooler fails and coolant cross-contaminates

Fix: Steel lines rot from road salt and age; internal radiator coolers can fail and mix ATF with coolant (catastrophic for trans). Replace lines with pre-bent or custom-bent stainless, add external cooler if towing or spirited driving. 3-5 hours depending on routing and cooler install.

Estimated cost: $400-1,200

Typical onset: 70,000-120,000 mi or engines that sat for years

Symptoms: Blue smoke on deceleration or startup, Excessive crankcase pressure, oil pushed past PCV, Poor compression across multiple cylinders, Wet-fouled spark plugs

Fix: Rings lose tension from age and heat cycling; bores glaze from extended idling or poor break-in decades ago. Full teardown, hone cylinders, replace rings and check pistons for cracking. Often bundled with bottom-end work. 20-30 hours if doing rings and bearings together.

Estimated cost: $3,500-6,500

Symptoms: Hard starting, long cranking before engine fires, Stalling at idle or under load after sitting, Surging or hesitation, especially after the car has been stored, Rust flakes or gel in fuel filter or carburetor bowl

Fix: Steel tanks rust from inside, old fuel leaves varnish. Drop tank, clean or line interior, replace all fuel hoses and filter, rebuild or replace carburetor, blow out fuel lines. 6-10 hours depending on tank condition and whether you send carb out.

Estimated cost: $800-2,000

Typical onset: 100,000+ mi or history of riding the clutch

Symptoms: Excessive crankshaft endplay—crank walks fore/aft, Grinding or squealing when clutch pedal is depressed or released, Clutch engagement point changes or clutch drags, Oil leak at front main seal from crank movement

Fix: Thrust surfaces on center main wear from clutch pressure or poor lubrication. Engine must come out, crank removed, thrust bearing replaced—sometimes requires crank grinding if surface is damaged. 25-30 hours including R&R.

Estimated cost: $4,000-7,000