Porsche Carrera Cabrio Tiptronic S
The M64/22 is technically identical to the M64/21 — same power, same VarioRam character, same sound. Intake surge from 5,000 rpm, the unmistakable air-cooled boxer rumble, the same top-end urgency. Reliability and maintenance needs match the M64/21 completely. The only difference is the gearbox: this engine was exclusively paired with the 4-speed Tiptronic S.
Relaxed cabriolet cruising with Tiptronic
In the cabriolet context the Tiptronic in the 993 is most tolerable — open-air driving, warm air and the unfiltered flat-six sound compensate somewhat for the missing shift feel. The consensus: "For relaxed outings it works, as a sports car experience it isn't." Cheapest entry into a VarioRam-engined 993. Mechanically uncomplicated, as the Tiptronic is very durable.
Engine Weaknesses 10
Porsche recalled approx. 20,000 vehicles (model years 1995–1996): bio-based plastic wiring harness insulation hardens, cracks under heat and vibration — short circuit and engine failure possible. Check recall status before purchase.
Symptoms: Electrical faults, engine failure, irregular injection; in the worst case a smouldering fire in the engine bay.
Plastic valve covers leak under heat and age. Metal press-fit inserts work loose. Oil drips onto the hot exhaust system — fire risk. Repair kit approx. €200–300.
Symptoms: Oil smell after driving; oil spots under the vehicle; visible oil film on the underside of the engine.
The gasket on the chain case housing (rear of the engine) leaks over time. Oil accumulates between engine and gearbox. Repair requires engine removal or at minimum gearbox separation.
Symptoms: Oil pooling between engine and gearbox; oil drops on the ground under the centre of the vehicle.
Hydraulic valve lifters lose pre-load as they wear. Brief ticking after a cold start is normal — persistent ticking even when warm indicates a defect.
Symptoms: Ticking noise from the engine; initially only cold, later also when warm; rough idle with advanced failure.
The DME relay fails through continuous energisation and heat. Typical breakdown scenario: starter cranks, engine won't fire. Often occurs after heat soaking (summer, full sun). At night or after cooling down the engine starts again — replace the relay first.
Symptoms: Engine cranks but won't start; no fuel pump priming noise after ignition ON; problem after heat soak.
Valve guides wear under heat and high RPM. Excessive clearance draws oil along the valve stems into the combustion chamber. The cylinder head must be removed for boring and pressing in new guides.
Symptoms: Blue smoke on overrun and when lifting off the throttle; elevated oil consumption; oily spark plugs (cylinder-specific).
Oil consumption rises with increasing mileage — mainly through valve stem seals and piston rings. Up to 0.5 L/1,000 km is considered acceptable; above that an inspection is needed.
Symptoms: Oil level drops faster than usual; slight blue smoke after a long cold start; oil consumption above 0.5 L/1,000 km.
The rocker shafts sit in a press-fit without a seal ring as standard. Oil seeps at the interface between shaft and cover material. Retrofit O-ring kit (RSR motorsport part) available — 12 rings per engine.
Symptoms: Oil film in the valve cover area; oil on hot engine components; smell after a short drive.
The vacuum capsules in the VarioRam intake system develop leaks. The variable intake switching mechanism no longer switches reliably — felt as missing torque increase from around 5,000 rpm.
Symptoms: No VarioRam kick above 5,000 rpm; hissing noises from the intake tract; VarioRam fault code stored.
The PTFE guides on the VarioRam slider tubes wear and develop play. The characteristic power surge at around 5,000 rpm is absent or weaker.
Symptoms: Missing power kick above 5,000 rpm; flat power curve; drop-off in the upper rev range.
Vehicle Weaknesses 13
Steel brake lines are particularly vulnerable to corrosion in the underbody area. Corroded brake lines are a significant safety hazard — replace completely if any deterioration is found.
Windscreen and rear window frames are prone to rust, especially if windows were replaced incorrectly. Moisture ingress and adhesive residue accelerate the attack.
Hollow sections of the rear bumper supports rust from the inside due to dirt accumulation. Regular cleaning and cavity preservation are essential.
The climate control panel can remain permanently switched on due to leakage current, draining the battery within 48 hours. Repairing the blower motor and temperature sensor is usually cheaper than a new unit.
Aluminium brake calipers corrode heavily, especially during winter use or extended storage. Pistons seize, braking becomes uneven. Rebuilding or replacement is necessary.
Steering rack tends to develop oil leaks with age. On vehicles prior to 1996 with 18-inch wheels without the factory supplement, there is a risk of steering rack fractures.
Control arm and suspension bushings age considerably. Knocking and cracking noises when compressing and steering indicate worn rubber-metal elements.
Alternator wears with age. Diodes, voltage regulator and bearing wear are typical failure causes. Rebuilt exchange units are considerably cheaper than new parts.
Central locking tends to fail due to cold solder joints in the control unit and worn actuators. Locks or unlocks immediately after the remote signal is received.
Window regulator relay clicks inconsistently. Worn cables, defective switches or damaged cable pulls are the most common causes of failures in the aged 993.
Rubber engine mounts harden with age and lose their damping function. Vibrating sensation at the gear lever and increased body vibration at idle.
Exhaust system joints corrode heavily, especially at vibration points of worn engine mounts. High heat generation and moisture in the rear section accelerate the attack.
Door hinge straps wear out, causing creaking and squeaking when opening. Heavy doors and age-related material fatigue accelerate the wear.
Reports & Tests
24 owner complaints filed with NHTSA (1993–1998). Most reported: Electrical (6), Airbags (4), Engine & Cooling (3).