1995 MERCEDES-BENZ G320 W463

Typical onset: 150,000-250,000 mi

Symptoms: Heavy knocking on cold start that persists after warm-up, Metal shavings in oil during changes, Low oil pressure at idle (under 10 PSI), Catastrophic failure if driven after knocking starts

Fix: Full engine-out teardown required. Crankshaft typically needs grinding or replacement, main and rod bearings, sometimes pistons if cylinder scoring present. 40-50 hours labor for proper rebuild with machine shop work. Many owners opt for used engine swap instead at 20-25 hours.

Estimated cost: $6,000-12,000

Typical onset: 120,000-180,000 mi

Symptoms: White smoke from exhaust on startup, Coolant loss with no visible leaks, Oil milkshake (coolant mixing with oil), Overheating under load or climbing grades, Bubbles in coolant reservoir when running

Fix: Head removal mandatory, both heads typically done simultaneously. Heads must be pressure-tested and machined flat. ARP studs recommended over OEM bolts. 18-22 hours for both heads, includes timing chain components replacement while in there.

Estimated cost: $4,500-7,000

Typical onset: 80,000-150,000 mi

Symptoms: Pink fluid (ATF) mixed in coolant reservoir, Transmission slipping after engine reaches operating temp, Overheating transmission (burnt smell), Sudden loss of all gears if cooler ruptures completely

Fix: Cooler lines rust through where they connect to radiator. Requires radiator removal to properly replace lines and flush both cooling and transmission systems. If caught early, trans survives. If coolant entered trans, full rebuild needed. Line replacement alone: 6-8 hours. Trans rebuild adds 20+ hours.

Estimated cost: $1,200-2,500 (lines only), $4,500-7,000 (with trans rebuild)

Typical onset: 60,000-100,000 mi

Symptoms: Clunk when shifting from Park to Drive or Reverse, Excessive vibration at idle in gear, Visible sagging of transmission tail when inspected underneath, Drivetrain lurch during throttle application

Fix: Single rear transmission mount commonly fails on G-Wagens due to weight and off-road use. Requires trans support to replace. OEM mount strongly recommended over aftermarket. 2-3 hours labor.

Estimated cost: $400-700

Typical onset: 180,000-250,000 mi

Symptoms: Excessive oil consumption (1 quart per 500-800 miles), Blue smoke on deceleration, Poor compression test results (under 140 PSI), Oil residue in intake manifold

Fix: M104 ring lands can wear, especially if maintenance was neglected. Engine-out rebuild required. Cylinders must be honed, new rings fitted. If cylinder walls scored, overbore and oversized pistons needed. 35-45 hours for complete ring job with honing.

Estimated cost: $5,000-8,500

Symptoms: Rough running after sitting overnight, Stalling when fuel level drops below half tank, Repeated fuel filter clogging (replacing every 5,000 miles), Rust flakes visible in fuel filter housing

Fix: Steel fuel tanks rust from inside out, especially if vehicle sat or stored with partial fuel. New filters are Band-Aid. Requires tank removal, professional cleaning/sealing or replacement. Tank R&R is 8-10 hours due to frame-mounted spare tire and skid plates.

Estimated cost: $1,800-3,200