The 2016 Cayenne S with the 4.8L V8 (M48.02 engine) is generally solid, but suffers from catastrophic bore scoring issues that can grenade the engine without warning. When it hits, you're looking at a full rebuild or replacement—not a cheap fix on a Porsche.
Catastrophic Bore Scoring / Cylinder Wall Failure
Occasional · high severityTypical onset: 60,000-120,000 mi
Symptoms: Excessive oil consumption (more than 1 qt per 1,000 mi), Blue smoke on cold starts or hard acceleration, Loss of compression, misfires, rough idle, Metallic debris in oil during analysis
Fix: Complete engine rebuild with cylinder sleeving or block replacement. Requires 35-50 hours labor depending on shop approach. Some owners opt for used/rebuilt engine swap. Includes pistons, rings, bearings, gaskets, and machine work.
Estimated cost: $15,000-25,000
Transmission Oil Cooler Line Leaks
Common · medium severityTypical onset: 70,000-110,000 mi
Symptoms: ATF puddles under vehicle, typically passenger side, Low transmission fluid warning on dash, Burnt ATF smell, Transmission slipping or harsh shifts if fluid level drops
Fix: Replace oil cooler lines and seals. Requires removal of underbody panels and sometimes subframe components for access. 4-6 hours labor plus fluid refill and adaptation.
Estimated cost: $1,200-2,000
Transmission Mounts Deterioration
Common · low severityTypical onset: 80,000-130,000 mi
Symptoms: Clunking on acceleration or deceleration, Excessive drivetrain movement felt through cabin, Vibration at idle in Drive, Visible cracking or separation of rubber from metal
Fix: Replace transmission mount(s). Access varies but typically 2-4 hours labor. Often replaced alongside engine mounts as preventive measure.
Estimated cost: $600-1,200
Coolant Pipe Corrosion and Leaks
Occasional · medium severityTypical onset: 70,000-100,000 mi
Symptoms: Coolant smell in cabin or under hood, Visible coolant weeping from pipe junctions near cylinder heads, Low coolant warning, Overheating if leak progresses
Fix: Replace corroded coolant pipes—often the crossover pipes behind the engine. Labor-intensive due to location; requires intake manifold removal on V8. 8-12 hours labor.
Estimated cost: $2,000-3,500
Air Suspension Compressor and Line Failures
Common · medium severityTypical onset: 60,000-100,000 mi
Symptoms: Suspension fault warning on dash, Vehicle sagging on one corner or entire side, Compressor runs constantly or not at all, Hissing sound from suspension area
Fix: Replace air compressor, air struts, or supply lines depending on failure point. Compressor replacement 3-5 hours, strut 2-3 hours each. Many owners convert to coil springs to avoid repeat failures.
Estimated cost: $1,500-4,000
High-Pressure Fuel Pump Failure
Occasional · high severityTypical onset: 50,000-90,000 mi
Symptoms: Hard starting or extended cranking, Rough idle, misfires, stumbling under load, Fuel system fault codes (low fuel rail pressure), Limp mode or no-start condition
Fix: Replace high-pressure fuel pump mounted on engine. Includes fuel system depressurization and potential injector service if contamination occurred. 4-6 hours labor.
Estimated cost: $1,800-3,000
Only buy if you have a $20k engine-rebuild fund or can walk away from the car—bore scoring is Russian roulette, and when it hits, the bill is massive.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.