1985 CADILLAC CIMARRON

Typical onset: 80,000-120,000 mi

Symptoms: Severe knocking or rattling from crankcase, especially when cold, Metal shavings in oil, low oil pressure warning, Connecting rod bearing failure leading to complete seizure

Fix: The 2.0L LQ5 suffers from inadequate bearing design and oil starvation under sustained highway use. Requires complete engine rebuild or replacement. Expect 16-20 hours labor for R&R plus machine work. Short block replacement is typical—full rebuild rarely cost-effective on these.

Estimated cost: $2,800-4,500

Typical onset: 60,000-100,000 mi

Symptoms: Rough idle, stalling at stoplights, Hard starting when engine is hot, Hesitation on acceleration, black smoke from exhaust

Fix: TBI units clog with varnish, injectors stick, and idle air control valves fail. Cleaning helps temporarily but replacement of TBI assembly and IAC valve is typical fix. 2-3 hours labor. Parts availability is spotty—many use rebuilt units.

Estimated cost: $450-850

Typical onset: 70,000-110,000 mi

Symptoms: Slipping between gears, especially 2nd to 3rd, Delayed engagement when shifting to drive, Transmission fluid dark brown or burnt smell

Fix: The THM125C three-speed is notoriously fragile, especially behind the V6. Clutch packs burn out, and the oil cooler lines often leak. Full rebuild runs 12-16 hours. Transmission mounts also fail frequently (2 hours), causing excessive drivetrain movement before the transmission itself grenades.

Estimated cost: $1,800-3,200

Typical onset: 90,000-140,000 mi

Symptoms: Intermittent no-start, engine cranks but won't fire, Sputtering or dying under load, Fuel smell in cabin or near tank

Fix: In-tank electric pump fails, but steel fuel lines from tank to engine also corrode through on the chassis. Pump replacement is 3-4 hours; fuel line replacement adds another 4-6 hours if you're doing it right with proper bending and routing. Fuel filter clogs fast if tank is rusty.

Estimated cost: $600-1,400

Typical onset: 100,000-150,000 mi

Symptoms: White smoke from exhaust, sweet coolant smell, Overheating, coolant loss with no visible leaks, Milky oil on dipstick or oil cap

Fix: The 2.8L V6 is more durable than the 2.0L but develops head gasket leaks due to age and thermal cycling. Head R&R is 8-12 hours labor, but often reveals cracked heads or warped surfaces requiring machining. Parts are cheap; labor kills you.

Estimated cost: $1,200-2,200

Symptoms: Intermittent stalling, no-start when hot, Backfiring through intake or exhaust, Engine quits suddenly with no warning

Fix: GM's HEI distributor ignition modules fail when hot—classic issue across J-bodies. Replacement module is 1 hour labor. Distributor cap and rotor also crack frequently. Keep a spare module in the glovebox if you're driving this regularly.

Estimated cost: $180-350

Typical onset: 60,000-90,000 mi

Symptoms: Clunking over bumps from front suspension, Steering binding or grinding when turning at low speed, Uneven tire wear on front tires

Fix: Strut mount bearings seize or the rubber mounts tear, causing noise and poor handling. Replacement requires spring compressor and alignment afterward. 3-4 hours labor for both sides. Not dangerous but makes the car drive like a hay wagon.

Estimated cost: $400-700