2007 LINCOLN MARK LT

Typical onset: 80,000-150,000 mi

Symptoms: Cold-start rattle that lasts 5-30 seconds (sounds like marbles in a can), Check engine light with P0340-P0349 camshaft position codes, Reduced power and rough idle as it progresses, Metal shavings in oil if phasers are disintegrating

Fix: Requires front engine teardown to replace both cam phasers, timing chains, guides, and tensioners. This is 12-16 hours of labor. Many shops also replace the oil pump drive while they're in there. If you wait too long and metal contaminates the engine, you're looking at engine replacement.

Estimated cost: $2,800-4,500

Typical onset: 60,000-100,000 mi

Symptoms: Plugs break off during removal due to carbon buildup on long electrode, In extreme cases, plugs blow out of the cylinder head under load, Misfires on one or more cylinders, Stripped threads in aluminum head if plug ejects

Fix: The 2004-2007 3-valve 5.4L uses a 2-piece plug design that seizes. Normal plug change can turn into extraction job requiring special tools (Lisle 65600) or drilling/tapping. Budget 4-6 hours if multiple plugs break. If a plug ejects, HeliCoil or TimeSert thread repair adds another 2-3 hours per hole. Some techs pre-soak plugs overnight with PB Blaster to improve odds.

Estimated cost: $400-1,200

Typical onset: 100,000-140,000 mi

Symptoms: Transmission fluid leaking from steel lines at radiator connections (rust perforation), Strawberry milkshake in coolant overflow (internal cooler failure mixing ATF and coolant), Transmission slipping or delayed engagement after cooler contamination, Overheating transmission or engine

Fix: External line corrosion is 1-2 hours to replace steel lines. Internal radiator cooler failure is catastrophic—coolant gets pumped into transmission, destroying clutches and valve body. Requires radiator replacement, transmission flush or rebuild, and all cooler lines. If caught early (just lines), $300-600. If internal failure contaminates trans, you're at full rebuild territory: 8-12 hours labor.

Estimated cost: $300-4,800

Typical onset: 90,000-130,000 mi

Symptoms: Gear oil drips on driveway under rear of truck, Oil coating rear of differential housing, Whining noise from rear axle if oil level gets very low

Fix: The pinion seal on the 9.75" rear end leaks from age and heat cycles. Requires driveshaft removal, pinion nut removal with special tools, seal replacement, and proper pinion preload reset. About 2-3 hours labor. Not an emergency unless you let it run dry, but it will coat your undercarriage in 75W-140.

Estimated cost: $350-600

Typical onset: 80,000-120,000 mi

Symptoms: Growling or humming noise from front end that changes with speed, Noise gets louder in turns (loaded outer bearing), ABS or traction control lights if sensor integrated in hub fails, Vibration through steering wheel

Fix: Mark LT uses the same front hub assemblies as F-150. They're bolt-on units (not pressed), so replacement is straightforward: 1.5-2 hours per side. Always replace in pairs if one fails over 100K miles—the other is close behind. Quality matters; cheap hubs fail early.

Estimated cost: $400-700

Symptoms: No-start condition (cranks but won't fire), Intermittent stalling, especially when hot, Fuel pump not priming when key is turned on (no hum from tank), Check engine light with P0230 fuel pump circuit code

Fix: The fuel pump driver module (FPDM) is mounted to the frame rail above the spare tire. It's a known weak point on 2004-2008 F-150 platform trucks. Replacement is simple—unbolt old module, bolt on new one, reconnect harness. 0.5-1 hour labor, but the part itself is $150-300. Keep a spare in the glovebox if you're remote often.

Estimated cost: $250-450