2004 BENTLEY ARNAGE

Typical onset: 70,000-120,000 mi

Symptoms: Heavy oil consumption (1+ quart per 500 miles), Blue smoke on startup or acceleration, Metallic knocking from bottom end, Low oil pressure warning, Complete loss of power or engine seizure

Fix: Full engine rebuild required - remove engine, disassemble, machine block and heads, replace all pistons, rings, bearings, gaskets. This is 60-80 hours of labor at a specialist shop. Often find scored cylinder walls, spun bearings, and collapsed piston ring lands from deferred oil changes or using wrong oil spec. These engines MUST have proper oil (Mobil 1 0W-40 or equivalent) changed every 5,000 miles maximum.

Estimated cost: $18,000-35,000

Typical onset: 60,000-100,000 mi

Symptoms: Pink or milky transmission fluid, Transmission slipping or delayed engagement, Overheating transmission temp warning, Coolant level drops with no visible leaks, Rough shifting or failure to shift

Fix: Replace transmission oil cooler and flush both cooling system and transmission. If caught early, 8-12 hours labor. If coolant has contaminated transmission, you're looking at transmission rebuild adding another 20-30 hours. The cooler is integrated into the radiator assembly on some variants, making it expensive. Always check trans fluid color on these - contamination kills the ZF transmission fast.

Estimated cost: $2,500-4,500 (cooler only), $8,000-15,000 (with transmission rebuild)

Typical onset: 80,000-140,000 mi

Symptoms: White smoke from exhaust, Overheating issues, Coolant loss with no external leaks, Rough idle or misfires, Oil contamination in coolant reservoir or vice versa

Fix: Both head gaskets typically fail due to age and thermal cycling. Engine-out job on these - 40-50 hours labor. Must resurface heads, replace all head bolts (TTY), timing components while in there. Often find warped heads requiring extensive machine work. This is a specialist-only job due to engine complexity and need for proper torque sequences.

Estimated cost: $12,000-18,000

Typical onset: 70,000-110,000 mi

Symptoms: Harsh or delayed shifts, Stuck in one gear (limp mode), Check engine light with transmission codes, Erratic shifting patterns, Transmission banging into gear from stop

Fix: Replace complete valve body solenoid pack. Transmission pan must come down, filter replaced, valve body R&R. 6-8 hours labor. These solenoids wear from heat and contaminated fluid. Always replace transmission mount at same time as they collapse and cause harsh shifting that accelerates solenoid wear. Use only OE ZF solenoids - aftermarket ones fail quickly.

Estimated cost: $2,200-3,800

Symptoms: Rough running or misfires under load, Loss of power at highway speeds, Extended cranking before start, Stalling when hot, Limp mode activation

Fix: Replace main fuel filter and check in-tank pump filters. The 2004 has multiple filters that clog from ethanol fuel degradation and tank sediment. 2-3 hours labor for main filter, but tank may need dropping if pump filters are clogged (add 4-6 hours). These cars sit a lot, leading to varnished fuel and filter clogging. Keep tank above half-full and use quality fuel with stabilizer if storing.

Estimated cost: $400-800 (main filter), $1,500-2,500 (including tank work)

Typical onset: 90,000-150,000 mi

Symptoms: Deep knocking noise from lower engine, Low oil pressure at idle, Metal shavings in oil, Vibration through chassis, Sudden catastrophic engine failure

Fix: Engine must come out for crank removal and bearing replacement. 50-70 hours labor. Usually find scored crank journals requiring grinding or replacement crank. Almost always caused by oil starvation from missed changes or running low. When one bearing goes, others are typically damaged too, necessitating complete bearing set and crank work. Often done during full rebuild.

Estimated cost: $15,000-25,000