2018 FORD F-250

Typical onset: 60,000-150,000 mi

Symptoms: Excessive blow-by and oil consumption (1+ quart per 1,000 miles), White or blue smoke on acceleration, Loss of power and reduced boost pressure, Metallic knocking or rattling from engine block, Check engine light with low compression codes

Fix: This is the big one. Ford issued TSB 19-2383 acknowledging piston cracking issues on 2017-2019 6.7L engines. Requires complete engine teardown, all pistons and rings replaced, often includes connecting rod bearings and main bearings while you're in there. 30-45 hours labor depending on cab-on or cab-off approach. Some shops pull the engine, others work cab-on. If caught early, piston/ring replacement suffices; if ignored, you're looking at crankshaft damage and full short block.

Estimated cost: $8,000-15,000

Typical onset: 40,000-90,000 mi

Symptoms: Transmission fluid leaking from front of vehicle near radiator, Pink or red fluid pooling under truck, Transmission overheating warning light, Harsh or delayed shifting when towing, Milky transmission fluid (if coolant mixes in)

Fix: The quick-disconnect fittings on the 6R140 transmission cooler lines crack or corrode, especially on trucks in salt-belt states. If coolant enters the transmission (cross-contamination through the cooler), you're replacing the transmission. Caught early, it's just cooler lines and possibly the external cooler. 2-4 hours labor for lines only, add transmission flush. If trans is contaminated, you're at 12-18 hours for a rebuild or replacement.

Estimated cost: $600-1,200 (lines only), $4,500-7,000 (if transmission damaged)

Typical onset: 60,000-100,000 mi

Symptoms: Clunking or banging when shifting into drive or reverse, Excessive vibration in cab at idle, Visible separation or tearing of rubber mount, Driveline shudder during acceleration

Fix: The 6R140 transmission is heavy and the crossmember mount fatigues, especially on trucks used for towing or off-road. Replacement is straightforward—support transmission, unbolt old mount, bolt in new. 1.5-2.5 hours labor. OE Ford mount recommended over aftermarket for longevity.

Estimated cost: $300-500

Typical onset: 50,000-120,000 mi

Symptoms: Diesel fuel odor in cab or around engine bay, Visible fuel wetness on top of fuel filter housing, Hard starting after sitting overnight (air intrusion), Rough idle or low fuel pressure codes

Fix: The fuel filter cap O-rings on the 6.7L dry-rot and allow air into the system or fuel to seep out. Replace O-rings during every fuel filter service (Ford recommends every 20,000 miles). If neglected, air intrusion causes hard starts and potential high-pressure fuel pump damage. 0.5-1 hour labor if caught during filter change.

Estimated cost: $150-300

Typical onset: 80,000-150,000 mi

Symptoms: Check engine light with DEF system fault codes (P20EE, P204F), "Derate in 200 miles" warning on instrument cluster, Poor DEF fluid quality detected message, Reduced engine power (limp mode)

Fix: DEF (diesel exhaust fluid) crystallizes in the injector or supply lines if low-quality fluid is used or if the system isn't purged after long sits. Requires DEF injector replacement and thorough system flush. If the DEF tank heater or level sensor fails simultaneously, add those parts. 3-5 hours labor. Use only OEM or top-tier DEF to prevent this.

Estimated cost: $1,200-2,200

Typical onset: 100,000-180,000 mi

Symptoms: Loss of power under load or towing, Black smoke on acceleration, Check engine light with turbo underboost codes (P0234, P003A), Turbo whistle or flutter at idle

Fix: The variable geometry turbo actuator sticks due to carbon buildup or internal wear. Sometimes cleanable with intake and EGR service, but often requires actuator replacement or full turbo rebuild. Actuator alone is 4-6 hours; full turbo is 8-12 hours due to exhaust manifold removal. Preventive: use quality oil and don't idle excessively.

Estimated cost: $800-1,500 (actuator), $2,500-4,000 (turbo rebuild/replacement)