2018 PORSCHE CAYENNE S

Typical onset: 60,000-120,000 mi

Symptoms: Blue smoke on cold start that clears after warmup, Excessive oil consumption (>1 qt per 1,000 mi), Rough idle, misfires on multiple cylinders, Metallic rattling from block, oil pressure warnings

Fix: Bore scoring requires complete engine rebuild or replacement. Pistons, rings, cylinder liners (sleeving), bearings, gaskets—basically a ground-up rebuild. 40-60 hours labor at an indie. Factory reman long block is $25k-30k before labor; used engines are gambles.

Estimated cost: $15,000-35,000

Typical onset: 70,000-100,000 mi

Symptoms: Coolant loss with no visible external leaks, Overheating or low coolant warnings, White smoke from exhaust (coolant entering cylinders), Rough running, possible hydro-lock if severe

Fix: Plastic coolant pipes at the back of the V8 crack and leak internally into the cylinder valley or externally. Requires engine-out or near-complete disassembly to access. 18-25 hours labor. Often discovered during other engine work. If coolant enters cylinders, can cause scoring and escalate to full rebuild.

Estimated cost: $4,000-7,500

Typical onset: 80,000-120,000 mi

Symptoms: Transmission fluid puddles under vehicle, Burnt ATF smell, brown fluid on cooler lines, Harsh shifts or slipping if fluid level drops significantly

Fix: Oil cooler lines corrode or cooler itself develops pinhole leaks. Cooler replacement involves dropping undertray, disconnecting lines, and refilling ATF. 3-5 hours labor. If caught early, no trans damage. Ignored, leads to overheating and internal trans wear.

Estimated cost: $800-1,500

Typical onset: 70,000-100,000 mi

Symptoms: Clunking or thudding on acceleration/deceleration, Vibration through cabin at idle in Drive, Excessive driveline movement felt during shifts

Fix: Rubber mount deteriorates, allowing trans to sag and move excessively. Replacement requires supporting trans, unbolting old mount, installing new. 2-3 hours labor. Often done alongside other trans work.

Estimated cost: $600-1,200

Symptoms: Hard starting, extended cranking, Loss of power under load, hesitation, Fuel system fault codes (low pressure), Rough idle, stumbling

Fix: In-tank fuel filter or high-pressure pump pre-filter clogs, often from contaminated fuel or tank debris. Requires dropping fuel tank, accessing pump assembly, replacing filter and checking pump. 4-6 hours labor. If pump is damaged, add another $800-1,200 in parts.

Estimated cost: $900-2,000

Typical onset: 100,000+ mi

Symptoms: Rattling from front of engine on cold start, Check engine light with cam/crank correlation codes, Metallic grinding noise that worsens over time

Fix: Timing chain guides wear, tensioners lose pressure. If chain skips, valves meet pistons—game over. Requires front-engine disassembly, all chains, guides, tensioners. 20-30 hours labor. Often done preventively during other major engine work.

Estimated cost: $5,000-9,000