The 987 spans two entirely different engine families, and the reliability picture depends on which one you have.
M96 / M97 (987.1, 2005-2008)
The 987.1 uses the water-cooled M96 (2.7 base) and M97 (3.4 S) flat-six, closely related to the 996/997.1 units. They are port-injected, use VarioCam (VarioCam Plus with two-stage valve lift on the M97), and drive the camshafts through an intermediate shaft (IMS). Two known risks live here:
- IMS bearing failure. A sealed bearing supports the intermediate shaft; if its grease seal degrades the bearing can starve and disintegrate, potentially destroying the engine. Risk is highest on the earliest MY2005 Boxster with the small single-row bearing; the larger 2006-2008 bearing (and all Caymans) has a much lower failure rate.
- Cylinder bore scoring. The Lokasil open-deck liners can score vertically, worst on the M97 3.4 S. Symptoms are a cold ticking knock, oil consumption, and sooty exhaust.
DFI 9A1 (987.2, 2009-2012)
The 987.2 switched to the all-aluminium DFI 9A1 (2.9 and 3.4). The camshafts are chain-driven directly off the crankshaft, so there is no intermediate shaft and no IMS bearing — the failure that worries M96/M97 buyers simply does not exist here, and bore scoring is far rarer. In its place, direct injection brings a high-pressure fuel pump (HPFP) as the notable new wear item.
Both families take Porsche A40-approved oil (factory fill 0W-40) and hold roughly 7.5-7.75 L with a filter.
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