1990 BMW 325IS

Typical onset: 80,000-150,000 mi

Symptoms: Overheating under load or in traffic, Coolant loss with no visible external leaks, Cracked expansion tank or brittle radiator neck, Water pump bearing noise or seepage

Fix: Replace radiator, water pump, thermostat, expansion tank, and all hoses as a package—aged plastic components fail in sequence. Budget 4-6 hours labor for the full system refresh.

Estimated cost: $800-1,400

Typical onset: 70,000-120,000 mi

Symptoms: Clunk on throttle lift or engagement, Excessive driveline vibration at idle in gear, Shifter slop or grinding on manual transmissions

Fix: Rubber mounts deteriorate and tear—transmission mount and rear differential mount both typical culprits. 2-3 hours labor each, accessible from underneath.

Estimated cost: $300-600

Typical onset: 100,000-180,000 mi

Symptoms: Oil seepage at head/block junction or pooling under valve cover, Burning oil smell from exhaust manifold heat, Coolant consumption without external drips (head gasket breach)

Fix: Valve cover gasket is a 1-hour job. Head gasket requires 8-12 hours—cylinder head removal, milling for flatness if warped, and full timing/cooling system refresh while you're in there.

Estimated cost: $400-700 (valve cover), $1,800-3,200 (head gasket)

Typical onset: 150,000+ mi

Symptoms: Rod knock or deep rumble at idle, worse when cold, Low oil pressure at operating temp, Metallic debris in oil filter or pan

Fix: Main or rod bearings wear out from neglected oil changes or prolonged overheating. Requires full teardown—crankshaft removal, bearings, honing, reassembly. 20-30 hours labor if you do it in-car; pulls often exceed car value. Short-block swap is faster but parts availability is poor.

Estimated cost: $3,500-6,000

Symptoms: Hard starting or stumbling under acceleration, Loss of power on highway pulls, Fuel pump whine or intermittent stalling

Fix: In-tank pump pre-filter screens clog with rust from 34-year-old steel tanks. Fuel filter (under car, near tank) should be replaced every 30k miles but often isn't. Drop tank, clean or replace pump assembly, new filter and lines. 3-4 hours labor.

Estimated cost: $400-900

Typical onset: 80,000-140,000 mi

Symptoms: Rear end wanders or feels loose over bumps, Clunking from rear suspension on uneven pavement, Uneven rear tire wear

Fix: Rubber trailing arm bushings crack and separate; subframe mounts compress. Bushing replacement requires pressing—4-6 hours with alignment. Polyurethane upgrades available but transmit more noise.

Estimated cost: $600-1,200

Symptoms: Intermittent gauge failures—fuel, temp, or speedo, Check engine light with no stored codes, Window or sunroof motors work intermittently

Fix: Corroded solder joints on circuit boards, aged wiring under carpet and behind dash. Cluster repair involves removal and reflow soldering—2 hours labor plus specialist rebuild fees. Wiring diagnosis is time-intensive.

Estimated cost: $300-800