2023 MCLAREN 720S

Typical onset: 15,000-40,000 mi

Symptoms: metallic knocking from engine bay especially under load, sudden loss of power, oil pressure warning, complete engine seizure in worst cases

Fix: Full engine rebuild or short block replacement required. Typically involves removing entire powertrain, replacing main bearings, rod bearings, and often pistons/rings if damage has progressed. 60-80 labor hours at specialist facility. Root cause often traced to detonation from poor fuel quality, aggressive tuning, or inadequate oil cooling during track use.

Estimated cost: $35,000-65,000

Typical onset: 20,000-50,000 mi

Symptoms: transmission overheating warnings on dash, limp mode after spirited driving, burnt smell from trans fluid, erratic shifting when hot

Fix: Cooler itself fails or lines crack due to heat cycling. Requires dropping undertray, sometimes rear subframe work for access. Replace cooler, lines, and flush transmission fluid. If caught early, 8-12 hours labor. If trans was cooked, add clutch pack replacement and you're looking at transmission-out work.

Estimated cost: $4,500-8,500

Typical onset: 25,000-60,000 mi

Symptoms: white smoke from exhaust, coolant loss with no visible leaks, rough idle and misfires, oil contamination in coolant reservoir

Fix: M840T is sensitive to fuel octane and heat. Running pump premium (91 octane) instead of required 93+ or track use without proper cool-down leads to head gasket breaches. Engine-out job, resurface heads if warped, replace gaskets and studs. 45-60 hours labor minimum.

Estimated cost: $18,000-28,000

Typical onset: 30,000-70,000 mi

Symptoms: hard shifts or delayed engagement, transmission fault codes, stuck in single gear, refusal to shift above 4th gear

Fix: SST dual-clutch transmission uses electronically-controlled solenoids that fail from heat and contamination. Requires dropping transmission, replacing entire solenoid pack, updating software. 12-18 hours labor. Often covered under extended warranty if you have it.

Estimated cost: $5,500-9,000

Typical onset: 10,000-35,000 mi

Symptoms: excessive oil consumption (quart per 500 miles), blue smoke on startup, loss of compression in one or more cylinders, rattling from damaged piston skirts

Fix: Aggressive driving with inadequate heat soak management causes ring land failures. Requires full teardown, piston replacement, honing cylinders, new rings on all pistons even if only one failed. 55-75 hours. Sometimes combined with bearing replacement if debris circulated.

Estimated cost: $25,000-45,000

Symptoms: hesitation under hard acceleration, loss of power above 5000 RPM, engine stumbling at WOT, check engine light with fuel trim codes

Fix: High-flow fuel system is sensitive to contamination. Filter requires partial tank drop and fuel system depressurization. Replace filter and sometimes entire pump assembly if debris damaged pump. 4-6 hours labor. Prevention: only fill at high-volume premium stations.

Estimated cost: $1,800-3,200