1984 BMW 533I

Typical onset: 150,000-250,000 mi

Symptoms: Low oil pressure at idle when hot, Blue smoke on startup or deceleration, Metallic knocking from crankcase, Excessive oil consumption (1qt per 500-1000 mi)

Fix: Full engine rebuild or short/long block replacement. Expect 25-35 hours labor for R&R plus machine work. Most shops pull the engine, replace bearings, rings, hone cylinders, deck head. Original Nikasil bores can score if oil changes were skipped.

Estimated cost: $4,500-8,500

Typical onset: 80,000-150,000 mi

Symptoms: Transmission fluid in coolant (milky radiator overflow), Engine coolant in transmission pan (burnt fluid, slipping), Overheating transmission, Sudden loss of forward gears

Fix: The integral cooler in the radiator corrodes and cross-contaminates. Requires radiator replacement, full transmission fluid flush, often transmission teardown if coolant got inside. 6-10 hours labor depending on transmission damage.

Estimated cost: $1,200-3,500

Typical onset: 60,000-120,000 mi

Symptoms: Clunk on hard acceleration or deceleration, Vibration through floorboard at idle in gear, Visible transmission sag when inspected on lift

Fix: Rubber mounts deteriorate and tear. Replace all mounts (engine and transmission) as a set. 2-3 hours labor, straightforward job.

Estimated cost: $400-700

Symptoms: Hard starting when hot, Rough idle, misfires, Hesitation under acceleration, Stalling after sitting

Fix: Old fuel systems gum up. Start with fuel filter (cheap, 0.5 hours), then injector cleaning or replacement. If the car sat for years, expect tank removal and cleaning. Bosch L-Jetronic injectors can often be ultrasonically cleaned.

Estimated cost: $150-1,200

Typical onset: any—age-related

Symptoms: Coolant leaks from thermostat housing or expansion tank, Overheating, Cracked radiator neck, Burst expansion tank

Fix: All plastic cooling parts (expansion tank, thermostat housing, radiator end tanks) become brittle. Replace as preventive set with hoses, water pump, thermostat. 4-6 hours labor for full refresh.

Estimated cost: $800-1,500

Typical onset: any—age-related

Symptoms: Oil drips under car, Oil smell in cabin with heat on, Oil coating on exhaust manifold

Fix: Rubber gaskets harden. Valve cover gasket is easy (1.5 hours), oil pan requires subframe drop on some E28s (4-5 hours). Budget for rear main seal while you're in there if oil pan is off.

Estimated cost: $300-1,200

Symptoms: Intermittent no-start, Gauges cutting out, Lights flickering, Accessories working randomly

Fix: Wiring insulation cracks, grounds corrode, relays fail. Labor-intensive diagnosis (2-8 hours). Common culprits: main relay under dash, ground straps on intake manifold and chassis, corroded fuse box.

Estimated cost: $200-1,000