Porsche Turbo S
The MA1.70 is the last of the great Mezger lineage: 3.8L biturbo, GT1 engine block, VTG turbochargers — technology that won at Le Mans. Torque comes early, the turbo build-up is virtually lag-free thanks to the variable guide vanes. Thermally the engine operates at its limit: the GT1 block has coolant lines bonded with adhesive — after thermal cycles the fittings come loose, a weakness with tradition. Direct injection keeps combustion clean but builds carbon on the intake valves. The HPFP and VTG actuators are wear items with clear service needs. Drive the engine up to temperature regularly, preventively rivet the coolant lines and monitor oil quality, and you'll be rewarded with one of the most charismatic turbo flat-sixes ever made.
Turbo S, No Manual — Still
The Turbo S with 390 kW makes a power statement, and PDK is not a bad choice at this output level — shift times keep pace with the torque. The only missing element is the manual: the Turbo S 997.2 came exclusively with PDK, and that's the only blemish on an otherwise uncompromising sports car. Still fun though.
Engine Weaknesses 8
Coolant pipes in the GT1 engine block are bonded with adhesive, not mechanically retained. Heat cycling breaks the bond — coolant loss up to complete system failure. Engine damage possible.
Symptoms: Coolant loss, steam from engine bay, coolant warning; in the worst case sudden complete drainage of the cooling system
The VTG turbo canister housing corrodes internally from exhaust heat and moisture. Exhaust leaks at the canister; the part number is not available separately — complete turbo replacement required.
Symptoms: Exhaust smell, faint exhaust leak when engine is warm, power loss on one cylinder bank
The DFI high-pressure fuel pump (driven off the camshaft) fails internally. Cranking time increases, engine management enters limp mode. Replacement parts are often hard to source.
Symptoms: Extended cranking, briefly runs then dies, 'Engine power reduced' message, fault code P1023
The MA1.70 with its Alusil cylinder coating is not immune. Cold starts in extreme cold, clogged injectors and fuel contamination of the oil all increase the risk. Damage is typically on cylinders 4–6.
Symptoms: Rhythmic knocking (not a tick), increased oil consumption, sooty right exhaust side, aluminium particles in oil filter
PDK distance sensor fails and locks the gearbox in limp mode. Porsche's standard procedure is a complete gearbox replacement — specialists can replace just the sensor for significantly less.
Symptoms: Fault codes P1731–P1734, no reverse gear, gearbox in limp mode, 'Transmission fault' message
The ball-joint rods of the variable turbine geometry corrode, especially on cars from salt-belt regions. The actuator rod seizes and the turbo runs in a fixed geometry.
Symptoms: Uneven boost build-up, overboost or no boost, actuator no longer audibly cycles when ignition is switched on
Direct injection prevents fuel from washing the intake valves — blow-by oil bakes on. Cleaning requires considerable labour on a rear-engined car.
Symptoms: Light hesitation at part throttle, marginally higher fuel consumption, power loss in the mid-range with heavy build-up
Ignition coils on the 997.2 generation crack from heat and salt ingress. Often several fail simultaneously. Recommendation: replace all six when one fails.
Symptoms: Misfire on individual cylinders, engine stumble under load, misfire warning, rough idle
Vehicle Weaknesses 7
Damper piston rods corrode due to stone damage and moisture. Relevant for roadworthiness testing, as damper function is compromised.
Drain channels around the windscreen and luggage area clog with leaves and dirt. Water runs into the interior.
On 997 models from 2004–2008 the exhaust tailpipe can detach due to inadequate weld quality. Recall with free repair.
The 997 without underbody covers is susceptible to salt corrosion. Suspension components, springs, exhaust brackets and coolant hoses rust.
Both AC condensers become leaky through stone damage and corrosion after 12–15 years. Refrigerant loss leads to complete AC failure.
High-pressure hoses and steering rack seals become leaky after 10+ years. Hoses should be replaced preventively.
After a battery failure or replacement, the 997 loses the configuration that seat heating is installed. Recoding via diagnostics resolves the issue.
Reports & Tests
50 owner complaints filed with NHTSA (2004–2012). Most reported: Engine (41), Engine & Cooling (6), Wheels (2).