1992 MAZDA B2600

Typical onset: 80,000-140,000 mi

Symptoms: White smoke from exhaust, especially on cold start, Coolant loss with no visible leaks, Overheating under load or climbing grades, Milky oil on dipstick or oil cap, Rough idle and misfires when warmed up

Fix: Head gasket replacement requires 8-12 hours labor. Must resurface head (typically warped), replace timing chain components, water pump, and all coolant hoses while apart. The Mitsubishi G54B head bolts stretch and often require re-torquing. Many shops recommend replacing head bolts with ARP studs to prevent repeat failure.

Estimated cost: $1,800-3,200

Typical onset: 120,000-180,000 mi

Symptoms: Deep knocking sound from lower engine, worse under load, Metal shavings in oil filter or on drain plug magnet, Loss of oil pressure at idle when warm, Sudden catastrophic failure with rod through block

Fix: The G54B has marginal oiling to rod bearings, especially #3 and #4. Oil change neglect or running low accelerates wear. Repair requires complete disassembly (12-18 hours). Crank must be turned or replaced, all bearings, typically pistons/rings due to scoring. Most shops recommend short block replacement or used engine swap instead of rebuild due to age and availability of worn cores.

Estimated cost: $2,500-4,500

Symptoms: Transmission fluid leaking near radiator, Pink/red fluid mixing with coolant in overflow tank, Transmission slipping or erratic shifts after overheat event, Milky pink fluid on transmission dipstick

Fix: Steel cooler lines rust through where they connect to radiator, or internal cooler fails allowing cross-contamination. Requires immediate shutdown to prevent transmission damage from coolant ingestion. Fix involves replacing cooler lines (2 hours), flushing both systems, new radiator if internal cooler failed, and full transmission fluid exchange. If contamination reached transmission, rebuild is often necessary (add 10-14 hours).

Estimated cost: $400-800 (lines only), $2,200-3,800 (if transmission damaged)

Typical onset: 100,000-150,000 mi

Symptoms: Rattling noise from front of engine on cold start, quiets after 10-15 seconds, Check engine light with timing-related codes, Loss of power and rough running, Metal particles in oil

Fix: The G54B uses a timing chain with hydraulic tensioner that wears. Chain stretch and guide wear are common with oil change neglect. Replacement requires 6-8 hours, includes chain, tensioner, guides, and front seal. Must remove radiator and front accessories. Should always replace water pump and check cam/crank sprockets for wear during this service.

Estimated cost: $900-1,600

Symptoms: Hard starting when cold or hot, Stalling at idle or when coming to stops, Black smoke and poor fuel economy, Hesitation and flat spots during acceleration

Fix: Early B2600s use feedback carburetors that are maintenance nightmares. Rubber components dry out, passages clog with ethanol deposits, choke systems fail. Rebuild kits are scarce. Professional rebuild takes 3-4 hours but often doesn't solve all issues due to worn throttle shafts and warped bodies. Many owners convert to Weber 38/38 carburetor (2-3 hours install) for reliability.

Estimated cost: $350-600 (rebuild), $500-800 (Weber conversion)

Typical onset: 80,000-120,000 mi

Symptoms: Clunk when shifting into drive or reverse, Excessive driveline vibration, especially under load, Visible transmission sag or shift linkage misalignment, Difficulty shifting manual transmission

Fix: Rubber transmission mount deteriorates and tears. Replacement is straightforward (1-1.5 hours) but requires supporting transmission weight. Often replaced alongside engine mounts during clutch jobs on manual transmission trucks. Inspect driveline angles when replacing; collapsed mount can cause U-joint wear.

Estimated cost: $150-280