1996 CADILLAC FLEETWOOD

Typical onset: 60,000-100,000 mi

Symptoms: No-start or intermittent stalling, especially in wet weather, Misfires, rough idle, hesitation under load, Check engine light with multiple misfire codes

Fix: LT1's Achilles heel—distributor sits under water pump and fails from moisture intrusion or worn bearing. Requires water pump removal to access. 4-6 hours labor. Use vented aftermarket unit, replace water pump gaskets while you're in there.

Estimated cost: $800-1,400

Typical onset: 100,000-150,000 mi

Symptoms: Slipping or flare-up on 3-4 upshift, No third or fourth gear—feels like transmission is stuck in second, Burnt transmission fluid smell, dark fluid on dipstick

Fix: The 4L60-E behind this 260-hp LT1 grenades its 3-4 clutches from heat and line pressure issues. Requires full rebuild with upgraded clutches and servo components. 8-12 hours labor for R&R and rebuild, or swap in reman unit. Not a roadside fix.

Estimated cost: $2,200-3,800

Typical onset: 80,000-130,000 mi

Symptoms: Transmission fluid dripping near radiator or under engine, Low transmission fluid level, slipping shifts, Visible rust or wetness on steel cooler lines running to radiator

Fix: Factory steel lines rust through at crimps and bends, especially in salt states. Lines run front-to-back along frame rail. Replace both feed and return lines—don't patch. 2-3 hours labor. Consider switching to braided stainless aftermarket kit for longevity.

Estimated cost: $400-700

Typical onset: 90,000-140,000 mi

Symptoms: Coolant smell from engine bay, visible seepage at intake corners, Slow coolant loss with no external puddles, Rough cold-start idle from coolant seeping into cylinders overnight

Fix: Composite intake gaskets deteriorate and weep coolant externally or into crankcase. Not the instant-failure Dexcool disaster of later LS engines, but still a headache. Requires upper intake removal. 4-5 hours labor. Use Fel-Pro gasket set, flush Dexcool and switch to green coolant while you're in there.

Estimated cost: $650-1,100

Typical onset: 70,000-110,000 mi

Symptoms: Clunking over bumps from front suspension, Steering wander or shimmy at highway speed, Visible play when prying on lower control arm—tire moves in/out

Fix: GM recalled these for ball joint separation risk. Even if recall was done, joints wear from this car's 2.5-ton curb weight. Lower ball joints are riveted in—replacement requires drilling out rivets and bolting in new joints or replacing entire control arm. 3-4 hours labor both sides. Do alignment after.

Estimated cost: $500-900

Typical onset: 100,000-150,000 mi

Symptoms: No-start with crank but no fuel pressure, Stalling or hesitation under hard acceleration, Whining noise from fuel tank area before failure

Fix: In-tank pump quits from age and sediment. Requires dropping 25-gallon fuel tank on this body-on-frame chassis—easier than unibody cars but still a pain. Replace pump, strainer, and fuel filter together. 3-4 hours labor. Tank straps rust in salt states—inspect and replace if crusty.

Estimated cost: $600-1,000

Symptoms: Crank but no-start, security light on or flashing, Intermittent no-starts requiring 3-minute wait before retry, Worn key pellet or corroded contacts in steering column

Fix: GM's resistor-pellet key system fails from worn pellet contacts or broken wires in steering column harness. Diagnose with ohmmeter—match pellet resistance (1 of 15 values). Replace key or repair column harness. 1-2 hours labor. Bypass kits exist but disable factory security.

Estimated cost: $150-400