1980 BUICK REGAL

Typical onset: 60,000-90,000 mi

Symptoms: Slipping on 1-2 or 2-3 upshifts, especially under load, Delayed engagement into drive or reverse, Burnt transmission fluid smell and dark red-brown color, Loss of reverse gear entirely

Fix: The lightweight TH200 (metric 200) was never strong enough for V8 applications and fails prematurely. Rebuild requires 8-12 hours labor including R&R. Many shops recommend swapping to a TH350 for durability, adding 2-4 hours and $400-600 in adapter parts.

Estimated cost: $1,800-2,800

Typical onset: 40,000-80,000 mi

Symptoms: White smoke from exhaust indicating coolant intrusion, Head gasket failures between cylinders, Cracked cylinder heads from inadequate head bolt torque, Harmonic balancer separation causing timing chain failure, Fuel injection pump failure

Fix: GM's diesel conversion was fundamentally flawed with weak head bolts and no block reinforcement. Head gasket jobs require 12-16 hours but often reveal cracked heads. Complete engine rebuilds run 25-35 hours. Most techs recommend diesel-to-gas swaps instead as rebuilt diesels often fail again within 30,000 miles.

Estimated cost: $3,500-6,500

Symptoms: Hard starting when hot, floods easily, Severe hesitation or flat spots during acceleration, Black smoke and fuel smell from running too rich, Stalling at idle especially when air conditioning engaged

Fix: The Quadrajet and Dualjet carbs used outdated designs with vacuum-operated secondaries prone to diaphragm failure and internal wear. Complete rebuild kits run 4-6 hours labor, but many carbs have worn throttle shafts requiring replacement. Aftermarket Edelbrock conversions popular but require emission system modifications.

Estimated cost: $400-900

Typical onset: 50,000-100,000 mi

Symptoms: Check engine light illuminated constantly, Poor fuel economy (sub-12 MPG in V8 models), Rough idle and surging at steady throttle, Oxygen sensor and ECM connector corrosion

Fix: Early CCC systems suffer from corroded bulkhead connectors and failed oxygen sensors. Diagnosis is primitive with flash codes only. Oxygen sensors alone run 1-2 hours labor, ECM replacements 2-3 hours. NLA parts often require junkyard sourcing or aftermarket bypasses that may not pass emissions.

Estimated cost: $300-1,200

Symptoms: Visible rust through on rear wheel arches and lower quarters, Floor pan perforation especially driver's side, Body mounts rotted allowing body flex and door misalignment, Frame rust behind front wheels and at rear leaf spring mounts

Fix: G-body rust is structural and expensive. Body mount replacement requires body-lift equipment and runs 6-10 hours for all mounts. Floor pan replacement needs complete interior removal, 15-25 hours labor. Quarter panel rust often extends into inner structure. Salt-belt cars frequently beyond economical repair.

Estimated cost: $1,200-4,500

Typical onset: 80,000-120,000 mi

Symptoms: Gear oil leaking onto brake shoes causing pull and chatter, Howling or rumbling noise from rear that increases with speed, Hot differential smell after highway driving

Fix: GM 7.5 and 8.5 rear ends leak at axle seals when bearings wear. Both sides typically need service simultaneously. Requires axle removal, seal and bearing replacement per side, 3-5 hours labor total. Brake shoes contaminated by gear oil must be replaced, adding 2 hours and $80-150 parts.

Estimated cost: $500-900