BUYING A 993 C4S
As the final air-cooled 911, the 993 was appropriately robust and long lasting, but after 25 and more years, many will have required at least a degree of body and mechanical restoration. The M64/05 (pre-varioram) and M64/21 Varioram engines are remarkably reliable. Ray Northway has probably seen a dozen 150,000-plus mile examples over the years and provided they’ve had regular attention, all are in good mechanical health and perform well.
In general, the 993 never seemed to fall into the terrible states of neglect that some 964s did. Problems therefore tend to relate to ageing.
Oil leaks occur around the cam covers because these are made of plastic and lose their oiltightness after 15 or 20 years. Nicely machined alloy aftermarket replacements are expensive and not worth fitting, says Ray, because cheaper, standard Porsche parts will last another decade at least. Rebuilds of this engine are less common than on older 911s, and only significant oil loss because of worn valve guides tends to be a reason for dismantling – unless, of course, a component, for example in the valve train, has broken. As on any engine, fuel pumps and injection systems can go off-song, solenoids fail, but any properly maintained 993 should have had any rectifications necessary during routine servicing.
The C4S uses the M64/21 engine and often mechanical maladies here are the result of lack of use. Valves in the Varioram tubes can stick, as can other components. The clutch, too, can feel stiff, but quickly loosens up after a few depressions.
If it remains heavy and engages late, then it’s at the end of its life. The C2 and C4 993s were often company purchases – the giveaway is high mileage in their early years – and may be on their second or third clutches, but the original unit in a lightly used C4S should be in good order.
Suspension geometry on the 993 is sensitive. The front can go slightly off-kilter, which isn’t always easy to discern; only edge-profile wear on the front tyres betrays it. A recent document confirming that all corner measurements are within tolerance should be expected in the car’s history file. The front of the 993 can feel very light at high speed, and a geometry check is worthwhile before taking your C4S on the Autobahn.
The wholesale corrosion that bedevils impactbumper and earlier 911s was a thing of the past with the 993, and any paint bubbling on a body panel is probably the sign of poor repairs. A 993 weakness is corrosion around the windscreen, which may be hidden beneath the rubber seal. Body stays in the rear wings can rust through, but should have been replaced on a correctly serviced C4S. Again, any scrapes or damage to the underside panelling that could corrode the floor should have been made good. Dampness in the boot could suggest a frontal shunt and inadequate resealing of body joints.