The Overrev Counter - The numbers to check on any pre-purchase inspection
Make sure any PPI includes a report on the overrev counts.
A proper PPI means putting the car on a lift, pulling data straight from its computer systems, and checking the mechanical condition in a way that a test drive simply can't tell you. Before you hand over a deposit on a used 911, Cayman, or Boxster, there's a number buried in the car's ECU that can act like a bit of a tattletale and show a bit more about how the car has previously been driven - more than any service record can.
The overrev counter.
Porsche's engine control unit, the DME, keeps a permanent log of every ignition event that happens at or beyond the factory rev limiter. On most models since the late 2000s, this counter is broken into six ranges; 1 through 6. The system tallies both ignition count and hours.
The first few are soft limits, typically of spirited driving and or could be an indicator that the vehicle has seen some time on the track. Over revs in the 5 and 6 range should draw concern. Those indicate serious missed shifts or over rev events that could have left real internal damage to the engine.
Reading the overrev counter is only one piece of what we do during a Porsche pre-purchase inspection. A full PPI at our Redmond shop also includes a compression and leak-down test on every cylinder, a look at IMS bearing and rear main seal condition on the models where that's relevant, an inspection of suspension components and brake wear, a check of coolant and oil condition for signs of head gasket or seal trouble, a full scan of the car's other control modules for stored fault codes, and a visual inspection for accident history or corrosion that wouldn't show up in a vehicle history report.
The overrev log gets pulled alongside all of that, because a car's true condition only comes into focus when you look at the whole picture rather than any single test.
Seattle Area Porsche PPIs
If you are purchasing a used / pre-owned Porsche in the Seattle area, consider brining it to us to complete a full pre-purchase inspection. A clean CARFAX is great, but let us help keep you clear of a having a larger repair bill in the future. Bring the car to us in Redmond and we'll pull the DME data, complete a full mechanical inspection and get you the straight answers about what you might be purchasing - the same way we've been helping Porsche owners for the last four decades.
Schedule a pre-purchase inspection before you buy.
