1984 BUICK SKYLARK

Typical onset: 60,000-100,000 mi

Symptoms: slipping between gears especially 1-2 shift, delayed engagement when shifting to drive, shuddering during acceleration, transmission fluid appearing burnt or dark brown, complete loss of forward gears

Fix: The THM200C (Metric 200) was underbuilt for these cars and fails regularly. Rebuild requires 8-12 hours labor, but many shops recommend replacement with a used/rebuilt unit due to ongoing weak internal components. Torque converter often needs replacement simultaneously.

Estimated cost: $1,400-2,800

Typical onset: 40,000-80,000 mi

Symptoms: excessive white or blue smoke from exhaust, hard starting when warm, severe oil consumption 1+ quart per 500 miles, knocking or rattling from engine block, cracked cylinder heads, failed head gaskets with coolant mixing into oil

Fix: GM's 263 diesel is essentially a converted gasoline engine with inadequate block strength. Head bolt failures and cracked blocks are endemic. Most require complete engine replacement—rebuilds rarely last. Short blocks run 16-20 hours labor, long blocks 12-16 hours. Finding good used engines is difficult as most have similar issues.

Estimated cost: $3,500-6,500

Typical onset: 70,000-120,000 mi

Symptoms: heavy clunk when shifting from park to drive or reverse, excessive vibration at idle, visible engine movement when revving in park, transmission linkage feeling sloppy

Fix: Rubber mounts deteriorate and allow drivetrain movement that stresses the transmission cooler lines and shift linkage. Transmission mount replacement is 1.5-2 hours, engine mounts 2-3 hours depending on accessibility. Often done together as preventive maintenance.

Estimated cost: $250-550

Symptoms: transmission fluid puddles under front of vehicle, rapidly dropping transmission fluid level, transmission overheating, spray pattern of red fluid on undercarriage, smoke from hot fluid hitting exhaust

Fix: Steel cooler lines rust through at bends or vibrate against crossmembers until they crack. Failed engine/trans mounts accelerate this. Line replacement is 2-3 hours including fluid refill and system flush. Inspect all lines and rubber hoses when doing mount work.

Estimated cost: $300-600

Symptoms: rough idle especially when cold, hesitation or stumble during acceleration, high idle that won't come down, black smoke from exhaust, stalling when coming to stops, fuel smell in cabin

Fix: The Rochester 2SE carburetor develops vacuum leaks, worn throttle shafts, and stuck choke mechanisms. Rebuilds take 3-4 hours including adjustment time. Many techs replace with remanufactured units to save diagnostic time. Computer-controlled mixture solenoid frequently fails.

Estimated cost: $400-800

Typical onset: 80,000-140,000 mi

Symptoms: brake pedal slowly sinking to floor when stopped, spongy pedal feel that doesn't improve with bleeding, brake fluid level dropping without visible external leaks, rear brakes locking up prematurely

Fix: Internal seals fail allowing pressure loss and fluid bypass. The dual-chamber design may fail one circuit while other still works, masking the problem initially. Replacement is 2-3 hours including bleeding entire system. Always check for wheel cylinder leaks simultaneously.

Estimated cost: $250-450

Symptoms: hard starting especially in cold weather, loss of power under load, engine dying at idle after warm-up, air in fuel system requiring repeated bleeding, water in fuel filter housing

Fix: Diesel fuel systems require meticulous maintenance. Filter changes every 5,000 miles minimum, but contamination from tank rust is common in these aged vehicles. Mechanical lift pump failures require 2-3 hours to replace. Fuel system bleeding is time-consuming and frustrating.

Estimated cost: $200-500