Porsche 718 Cayman S 2.5 Turbo 982

The 718 uses a variable-flow water pump that relies on a vacuum-operated seal to regulate coolant flow. When this seal fails, coolant enters the vacuum lines or leaks externally. Porsche has acknowledged an abnormally high failure rate. Symptoms include coolant warning messages, a sweet smell in the engine bay, or visible coolant loss. Some owners have needed multiple replacements within 50,000 km. The pump itself costs around €300-500 in parts, but the mid-engine layout means partial exhaust removal is required, bringing total costs to €800-1,500 depending on whether a Porsche dealer (€1,200-1,500) or independent specialist (€800-1,000) does the work. Some owners have received goodwill coverage from Porsche due to the recognized failure pattern.

From early 2019, European-market 718 models were fitted with a gasoline particulate filter (GPF/OPF). Like diesel DPFs, these can clog if the car is driven predominantly at low RPM or on short trips where the filter never reaches regeneration temperature. Some owners have seen 100% saturation on diagnostic logs within 20,000-30,000 km. Porsche updated the filter part (982 254 400 AF) from December 2019 production onwards, and a software update helps earlier cars. A forced regeneration at a specialist costs around €500. Full replacement, where the GPF is integrated with the catalytic converter, can reach €5,000-6,000. Prevention: regular spirited driving with periods above 5,000 RPM. Pre-2019 cars and US-market cars are not affected. This issue is not specific to the 2.5 S, but it applies to all 2019+ 718 models.

The 7-speed PDK dual-clutch transmission is generally robust when properly maintained, but neglecting fluid changes (recommended every 60,000 km or 4 years) can lead to expensive failures. The most common fault is the distance sensor, which can cause loss of reverse gear or limp mode. Sensor replacement costs approximately €500-2,500 depending on the shop and whether the gearbox remains in the car. Valve body solenoid failures also occur. Porsche traditionally does not sell internal PDK parts for individual repair, but specialist shops now offer repair rather than full replacement. Full PDK replacement runs €20,000-25,000 but is rare and typically caused by prolonged neglect. Manual-equipped cars do not have this risk. Strict adherence to the PDK fluid interval is the single most important preventive measure.

The air oil separator prevents crankcase vapors from entering the intake system. When the internal diaphragm deteriorates, oil mist enters the intake manifold, causing misfires, rough idle, blue or white smoke on startup, and increased oil consumption. In severe cases, oil can foul spark plugs and contaminate catalytic converters. Porsche recommends AOS replacement every 75,000 miles or 6 years as preventive maintenance, but many owners are unaware of this interval. The part itself costs around €80-100, but the mid-engine layout makes labor the main expense, bringing total costs to €800-1,500. This typically becomes an issue after 80,000 km, and is more common on cars used for spirited driving or track days.

Rear main seal leaks are a known Porsche flat-engine trait across multiple generations. On the 718, the seal sits between the engine and transmission. A slow seep is manageable, but an active leak can drip onto the clutch (manual) or contaminate the PDK bellhousing. Repair requires transmission removal, which accounts for most of the cost (the seal itself is under €50). Total costs at a Porsche dealer run €2,000-2,500, while an independent specialist typically charges €1,200-1,800. Some owners combine RMS replacement with clutch or PDK fluid service to share the labor cost of transmission removal. This issue is not specific to the 2.5 S but affects all 718 models.

The 718 engine uses a hydraulic accessory belt tensioner with a typical service life of around 80,000-100,000 km or 6 years. When the tensioner weakens, it cannot maintain proper belt tension, causing a visible belt wobble or knocking sound on cold start. A telltale sign of impending failure is rust on the tensioner mounting bolt, which indicates hydraulic fluid leakage. The tensioner drives the water pump, AC compressor, and alternator, so failure risks cascading damage. Porsche has updated the tensioner part multiple times. Replacement costs €500-800 including parts and labor. This is a semi-predictable wear item, but because failure timing is variable and not on Porsche's standard service schedule, it qualifies as a risk rather than a fixed cost.

A common issue across many Porsche (and other European) models, caused by low-VOC adhesives required by EU regulations combined with the heat buildup in a small cabin. The headliner fabric detaches from the backing material, creating visible sagging. This is primarily cosmetic but affects the perceived quality of the interior. Porsche dealer replacement costs approximately €800-1,200. Independent upholstery shops can re-glue or replace the headliner for €400-600. Cars regularly parked in direct sun or hot climates show this issue sooner. Some owners have had repairs covered under warranty or goodwill.