1995 MITSUBISHI DIAMANTE

Typical onset: 80,000-150,000 mi

Symptoms: Rattling on cold start that doesn't go away quickly, Low oil pressure warning intermittently or constantly, Excessive oil consumption (more than 1 qt per 1,000 mi), Check engine light with misfire codes, Metal shavings in oil during changes

Fix: This engine sludges badly if oil changes exceed 3,000-4,000 mi intervals. Once sludge blocks oil passages, you're looking at spun bearings, scored cylinder walls, and complete engine failure. Repair means either a rebuild (25-35 hours labor) or short block replacement (20-28 hours). Both require removal. Connecting rod and main bearings frequently need replacement even on 'low-mile' examples due to inadequate lubrication from sludge.

Estimated cost: $3,500-6,500

Typical onset: 90,000-140,000 mi

Symptoms: Pink or milky transmission fluid (coolant mixing), Sudden transmission slipping or no forward gears, Overheating transmission temp gauge reading, Coolant loss with no visible external leaks, Transmission failure within days of coolant mixing

Fix: The factory oil cooler inside the radiator fails internally, allowing coolant and ATF to mix. Coolant destroys transmission clutches within 50-100 miles of driving. Fix requires radiator replacement, transmission rebuild or replacement (12-16 hours), complete fluid flush of cooling system, and all new ATF lines. This is a design flaw—preventive radiator replacement at 100k is cheaper than the aftermath.

Estimated cost: $2,800-5,200

Typical onset: 100,000-160,000 mi

Symptoms: White smoke from exhaust on startup, Overheating with no obvious coolant leaks, Bubbles in radiator or overflow tank when running, Coolant consumption without external puddles, Rough idle and cylinder misfire codes

Fix: These V6s blow head gaskets, often both banks simultaneously, typically after an overheating episode from radiator/water pump failure. Job requires pulling both heads, machining surfaces, and replacing gaskets on both sides (18-24 hours labor). Often discover warped heads requiring machining or replacement. Common to find corroded head bolts requiring extraction.

Estimated cost: $2,200-3,800

Typical onset: 120,000-180,000 mi

Symptoms: Blue smoke on deceleration or startup, Oil consumption exceeding 1 quart per 500 miles, Loss of compression in one or more cylinders, Rough running and poor acceleration, Fouled spark plugs repeatedly

Fix: Piston rings wear prematurely, especially if oil sludge was present earlier. Often accompanied by cylinder wall scoring requiring overbore or cylinder honing. A single piston replacement requires engine disassembly (15-20 hours), but most techs recommend doing all pistons and rings at once since you're already in there. Frequently escalates to full rebuild when cylinder damage is discovered.

Estimated cost: $2,800-5,000

Typical onset: 100,000-170,000 mi

Symptoms: Deep knocking sound from lower engine, worse under load, Oil pressure dropping at idle (below 10 psi), Metallic debris in oil filter during inspection, Vibration felt through entire vehicle, Eventually: catastrophic engine seizure

Fix: Main bearings fail from oil starvation (sludge-related) or extended oil change intervals. Requires complete engine teardown, crankshaft removal and inspection (20-28 hours). Crank often needs machining or replacement if journals are scored. This almost always justifies a complete rebuild or used engine swap instead of piecemeal repair.

Estimated cost: $3,200-6,000

Typical onset: 70,000-120,000 mi

Symptoms: Clunking when shifting from Park to Drive/Reverse, Excessive engine movement visible when accelerating, Vibration at idle in Drive, Transmission shifter feels loose or notchy

Fix: Hydraulic transmission mount fails, causing drivetrain movement and harsh shift feel. Relatively easy fix at 2-3 hours labor. OEM mounts last longer than aftermarket. Should be done before it causes secondary damage to CV axles or transmission linkage.

Estimated cost: $250-450

Symptoms: Hesitation or stumbling during acceleration, Hard starting after sitting overnight, Engine dying at idle or under load, Intermittent stalling, especially when fuel tank below 1/4

Fix: In-line fuel filter clogs if not replaced every 30,000 miles (which most owners skip). Also see fuel pump sock screen clogging in tank. Filter replacement is 0.5-1 hour; pump replacement requires tank drop at 3-4 hours. Rust in older tanks accelerates filter clogging.

Estimated cost: $120-650