Explained: The Porsche Over Rev Report

If you’ve arrived here, you’re likely looking into your next Porsche. Whilst potentially an issue for any manual gearbox equipped car, in the Porsche world, over revs are a big deal. Here, we explain why it’s become an important factor when buying or selling a Porsche. 

What exactly is a Porsche over rev report?

Quite simply, an over rev report is a check on whether the Porsche in question has gone beyond its rev limiter. An over rev report is a diagnostic check where a machine is plugged into the ECU to give you a breakdown of the amount of ignition cycles the car has spent on, or above the rev limiter. 

Depending on what Porsche we’re talking about, the over rev report is segmented into ranges – from simply kissing the limiter, up to the sort of revs that could be hiding serious engine damage.

Why are over rev reports so significant?

The reality is a mis-shift can occur in any manual gearbox car. However, as Porsche launched multiple track day weapons from the early 2000s, ranging from the Cayman R, to the GT3, to the GT2 RS, unsurprisingly many owners did just that – used them on track!

Compared to your typical car then, the chances of a baulked gearshift were greatly increased. Understandably then, if a Porsche dealer was to investigate engine troubles on a well-used GT3 RS, one of the first things they would check is if this was down to pilot error, rather than a manufacturing fault. 

And if somethings found? Then your warranty claim would be rejected. 

Should I walk away from a car without a rev report?

With stories like the above circulating owners’ forums, this has expanded to just about any manual Porsche being scrutinised. In reality though, the level of risk for your average Boxster is pretty low. However, it is worth noting that if you are in the market for a Porsche where you would like to retain or extend the official Porsche warranty, it will need to have a clean record.

Certainly, if you’re looking or have a Porsche GT car, then an over report is essential part of providing confidence, and there will impact how difficult it is to sell the car. 

The irony is, as these cars become increasingly cosseted, many want comfort in that their track-day ready Porsche has in fact never seen a track in its life. Therefore, even if a rev report isn’t extreme, evidence of regular infringements in the lower rev ranges indicates the car may have had a hard life.

What does a bad over rev report look like?

Earlier 986 and 996 models have two rev ranges – Rev 1 and Rev 2. The former is essentially the rev limiter, whereas the latter means it’s beyond the limiter.

For the 997 and beyond, the report is segmented into 6 rev ranges. Rev 1-2 are the rev limiter and nothing to worry about, and numbers within the ranges of Rev 3-4 are generally not concerning either, which is why Porsche will still happily warranty cars at this level despite Rev 4 being noted as likely to have caused “probable damage”. So, what you’re really looking for is evidence of activity within Rev 5-6 as this could lead to engine damage and – perhaps just as importantly – would mean your Porsche warranty is voided.

When the latest over rev happened – which is logged on an over rev report – is just as important. A small over rev from years ago is unlikely to suddenly raise as an issue 40,000 miles later, whereas in contrast a recent over-rev leaves a big question mark on whether the engine is going to cause you an expensive problem – it might also explain why the Porsche is for sale!

What are the consequences of over revving?

Often described as a “money shift” due to the impending engine rebuild, mistakenly grabbing first gear when you intended to select third is likely going to give you an instant result – normally with valves hitting pistons.

However, a less dramatic over rev can result in a stretched timing chain, and cause damage to bearings. When viewing a car, that’s where an expert ear can assist to listen out for unusual noises. Otherwise, there really is no telling what damage is caused without taking the engine apart.

Want to book an over rev report?

We charge a small fee for the use of our Porsche diagnostic of equipment, where we will ready the car’s ECU and provide a certified report. This can be separate to, or part of a more extensive pre-purchase inspection.