McLaren 720S 4.0 V8 P14

The 720S uses McLaren's signature hydraulic cross-linked suspension without conventional anti-roll bars. The system relies on four hydraulic accumulators that are consumable items and lose charge over 3-5 years. Symptoms include a harsher ride, uneven ride height, excessive body roll, and 'Damping Failure' warnings on the dashboard. A set of four OEM accumulators costs approximately €800-1,000, but dealer installation with hydraulic fluid bleed runs €2,500-3,500 total. Many owners upgrade to the 765LT-spec accumulators (€3,500-5,000 installed), which are reported to last longer. Refurbished accumulators with rechargeable bladders are available for around €1,000 for a set of four. Independent specialists can perform this work for 30-50% less than McLaren dealers. McLaren notably excludes accumulator wear from warranty coverage, so even relatively new cars may need this work at the owner's expense.

The OEM turbo inlet pipes contain internal resonator baffles (red silicone couplers) that can work loose over time, particularly under high boost. Once detached, the baffle material gets ingested by the turbocharger compressor wheel spinning at over 100,000 rpm. If caught early (baffle loose but not yet ingested), replacement with upgraded silicone inlets costs €500-800 at an independent specialist. If the baffle damages the compressor wheel, a full turbo rebuild or replacement is needed at €5,000-10,000 per unit. Symptoms include a P2261 fault code, intermittent black smoke from one exhaust bank, and reduced boost. Many experienced owners proactively replace the OEM inlets with aftermarket silicone versions as preventive maintenance during the first service. McLaren-specific specialist shops typically keep silicone inlet replacements in stock.

The 720S coupe features distinctive glass roof panels that are widely known to develop stress cracks, sometimes spontaneously. One dealer reportedly told an owner it was 'not a matter of if they crack but when.' Multiple generations of replacement glass (Gen 1, Gen 2, Gen 3) have all experienced this issue. OEM dealer replacement runs €5,000-10,000 per side including installation. Polycarbonate aftermarket replacements from specialists like AM Hot Rod Glass cost approximately €3,000-4,000 per pair installed, with a 2-year warranty. McLaren has carved this out from warranty coverage, meaning owners bear the full cost. Some owners have replaced the glass panels multiple times. This issue only affects coupe models with the glass roof; the Spider has a retractable hardtop and is not affected.

The signature upward-opening dihedral doors use hydraulic gas struts and position sensors that can fail over time. A healthy door should open fully by itself once unlatched; if it stops partway or requires pushing, the strut is weakening. A single gas strut replacement costs approximately €600-1,000 for the part, with 2-4 hours of labor. If the carbon-fibre door mounting bracket cracks (reported in a small number of cases), repair costs escalate to €3,000-5,000 due to specialist carbon repair work. Door position sensor failures trigger warning lights but are typically less expensive to resolve (€500-800). Regular inspection of the door hinges and struts during annual service can catch deterioration before complete failure.

The M840T engine generates considerable heat, and the coolant system has several potential leak points. The most common are hose clamp failures, where the OEM clamps loosen over time and allow seepage. These are cheap to fix (clamps cost approximately €5 each) but the labor to access them can be substantial: €500-800 at an independent shop, €1,500-2,500 at a dealer. More serious leaks can come from the radiators, which are positioned low and vulnerable to stone damage. A radiator replacement runs €2,000-3,500. Coolant loss that goes undetected can lead to overheating and potentially serious engine damage. Regular coolant level checks between services are strongly recommended.

Like many modern supercars, the 720S draws significant standby current from its electronic systems. The 12V battery can discharge within 7-14 days if the car is not driven or connected to a trickle charger. Under normal conditions with no parasitic drain issues, McLaren states the charge can last approximately 45 days, but many owners report shorter intervals. Some cases have been traced to faulty LIN-bus communication modules or battery management software issues. A quality trickle charger (CTEK or similar, €80-120) is considered essential equipment. Battery replacement itself costs €200-400. This is more of a characteristic of the car than a defect, but it catches many new owners off guard.

The McLaren Iris infotainment system is widely regarded as the car's weakest point. Common issues include frozen screens, boot loops (continuous restarts), unresponsive touch controls, failure to save media source preferences, and Wi-Fi dropping out. Early VIN cars benefited from a software update that addressed some issues, but the fundamental system remains problematic. Software updates at the dealer are typically free. If the infotainment unit itself fails, dealer replacement costs approximately €4,000-5,000. Many owners learn to live with the quirks or use their phone for navigation and audio instead. The system does not affect driving or safety functions.

The 7-speed SSG dual-clutch gearbox is manufactured by Graziano and is generally a strong unit. However, it has a known weakness in its main shaft bearings, which can develop wear over time. Symptoms include a whining noise under load, particularly in certain gears. During the warranty period, McLaren replaced entire gearboxes, but out-of-warranty repairs can be addressed with a bearing-only rebuild for approximately €5,000-8,000 at a specialist like Thorney Motorsport. A complete gearbox replacement costs approximately €14,000-15,000 plus VAT. The wet clutch pack itself is designed to last the lifetime of the car and does not require scheduled replacement, which is a significant advantage. This issue is relatively uncommon but very expensive when it occurs.