forsa355

I'm looking to buy a low mileage (~25k km) 2005 997 C2 and just had them do a DME report for me. There are some over revs in higher ranges but I'm not sure if this is anything to be concerned about. What does this mean?

Number of ignitions range 1 - 257/815h
Number of ignitions range 2 - 26/815h
Number of ignitions range 3 - 16/815h
Number of ignitions range 4 - 15/815h
Number of ignitions range 5 - 15/815h
Number of ignitions range 6 - 2/815h

Operating hours - 842

thanks in advance for the help!

Hella-Buggin'

Looks like someone missed a shift a little while ago. I woul pass. There are other cars out there. Anything over level 3 is considered a general deal breaker.

Jim Michaels

That must be the quickest trip to Range 6 that I've seen posted. The part that I find unusual is the Range 3 to 5 pattern of 16, 15, and 15 ignitions. I don't understand how the engine could rev so quickly up though those ranges and back down, leaving the same number of ignitions in three ranges. Time spent in Range 6 must have been quicker than an eye blink. Perhaps someone would be kind enough to enlighten me.

Hella-Buggin'

True, it could be a computer glitch. Can you ask for a rescan?

forsa355

I'll see if I can get a rescan. I was there when he did it and he was using a borrowed Durametric/laptop and never actually used it before. Is it possible to get flakey readings if you don't use it properly?

btw, the car also has a FVD DME flash - I know that boosts the rev limit, but would that affect these readings?

forsa355

double post...

Macster

Might be a long shot but maybe when the FVD DME flash was applied this resulted in some spurious over rev range counter writes?

If the overrevs are real they happened at 815 hours and the engine now has run 842 hours. That's 27 hours of running.

Let's see... 25000km is 15530 miles. 15530 miles divided by 842 hours is an average speed of 18.44mph.

You know that's a pretty low speed average. The car must have been a boulevard cruiser with nary a mile spent at highway speeds to have that low a speed average. I assume you have as best you can confirmed the mileage is right by service invoices and mileages say by getting a CarFax report with mileages listed at various points in the car's history?

Anyhow 27 hours times 18.44 mph is 498 miles. That's a good number of miles for an engine ro tun without any signs of any issues arising from those overrevs as sinister as they appear to be.

As an aside Porsche techs tell me that they would want to have the engine run an hour after an "overrev" event just to give the engine time to manifest any issues though if the overrevs are too high generally the driver knows it right then and there.

I would think that if anything bad happened from those overrevs the engine would be exhibiting the signs of it by now.

Be sure to give the car a thorough test ride/drive to make sure it runs ok.

Sincerely,

Macster.

forsa355

the mileage is legit... it's been a garage queen (and for peace of mind, I will doing the IMS bearing upgrade asap if I buy it).

I'm pretty sure the DME flash was done before the over rev event being shown, so not sure if the actual flashing introduced a false reading. I'll find out approximately when the flash was done.

jhbrennan

If you can, get a DME scan with the Porsche PIWIS - my experience with Durametric is that extraneous 1 ignition increments do and can show up with their readouts.

Jim Michaels

Several of the highly questionable over-rev reports that have been posted (here or at planet-9) showed seemingly impossible ignition patterns, such as one or two ignitions in multiple higher ranges. I don't know that DME flashes have been shown to create such anomalies, but I'm beginning to suspect that a brief electronic surge of some sort can result in unusual scan-reported ignition patterns in rev ranges that the engine has never actually reached.

Maybe if you search "over-rev reports" some of these over-rev anomaly posts will show up. A fairly recent one (maybe at planet-9) got my sympathy. The dealer refused approval of a lease return because the DME report showed single ignitions in the higher ranges. Our efforts to convince the dealer (and presumably their certified Porsche technicians) that it would be impossible for the engine to actually produce such an ignition pattern were apparently rejected as just junk off the internet.

USMC_DS1

My '08 C2S was under warranty + CPO when I purchased it from the P-dealer early last year. Only a couple of over revs(400+ in Range #1 and 25 in Range #2 but 1 over rev in ranges 3-5). I got the DME print out emailed to me from the dealer with email time stamp and proof of the car's state prior to purchase. The 1 over rev is impossible and an anomaly according to the p-dealer when I purchased the car... they'll obviously tell you one thing when selling the car and another when receiving a car.

Re FVD, you should be able to back flash it to stock. See if that helps but I would be surprised if the ECU flash caused an over rev reading issue. See if the PO has both files: tuned and stock. You want both for dealer servicing purposes. I have an FVD ECU flash and Durametric tool... none of the issues discussed here have shown up on my car before or after flash.

My one concern here is that even if this car did not really have any issues(real or not) with the over revs... it will be a real issue when you want to sell the car later if you cannot clear those over revs. Hopefully you got a great price to offset the potential selling issues at a later date.

Jim Michaels

For anyone with the time and interest, here is the thread that I referred to in Post #10 above. Cayman Driver's car had 567 ignitions in Range 1, and 1 ignition in each of Ranges 2 through 5. The dealer would not approve his lease return because of those single ignitions.

http://www.planet-9.com/987-cayman-b...e-readout.html

USMC_DS1

This sounds like is a French/German issue I've come across in some of my work with them in the past... legacy of WWI and WWII. Otherwise it's just pure greed, lack of customer service, and stupidity on the part of that French p-dealer... more likely all of the above. That poor Cayman owner in France needs to go directly to Porsche AG and consider moving to a different country.

Macster

DME flashes accounting for the overrev counts in the higher (or any for that matter) ranges is unlikely, I agree. It did occur to me but with some more thinking I, well, I have to agree with you.

Where I disagree with you, in a most cordial fashion, is I doubt there's an electronic surge or glitch that can account for these seemingly spurious over rev counts. I mean it is a good theory but I think I'd have to dismiss it.

In writing to flash the location has to be erased (all bit positions set to 1) and the data written. I find it hard to imagine a scenario in which this could result in a writing one or more bits that should be zero as a 1. The numbers -- admittedly the few I've seen -- do not appear to the result of bad flash hardware or bad flash writing firmware/software.

On the way to work this AM I thought about this some more and I wonder -- this is my theory at any rate -- if these seemingly implausible over rev range counts in the higher over rev ranges is some kind of a DME flash or even an over rev range counter tamper indicator?

Now before I go on I want to make it clear I certainly do not seek to cast suspicion on anyone unfortunate enough to be denied a warranty repair on an engine or have had trouble with a lease return by suggesting it was because of DME and DME over rev range tampering without more than just my imagination to go on, this theory as just me thinking (or trying to think) out loud.

The car leaves the factory with God only knows what written into these locations, though the lower ranges would probably have 0's.

The values are noted in the factory's records of the car.

When the car is prepared for sale a DME scan is done and the readings are recorded and sent back to the factory to see if the readings agree.

Then at subsequent services another DME scan is done and the readings noted and sent back to the factory. It is possible that some of these counter locations get new/different values too.

If the over rev counters show signs of having been tampered with the factory probably does nothing unless the car comes in for some warranty work (or is a lease return) and then notes the over rev range counters show signs of tampering.

Anyhow the numbers appear to be numbers that are at least to my level of investigation implausible and I suspect chosen that way on purpose.

If, a very very big if, my theory is right.

Sincerely,

Macster.

Jim Michaels

I like your theory, Macster. It would seem to logically account for several aspects of the over-rev puzzle. First, if true, it might account for why some anomaly over-rev counts have all 1's in the upper ranges (perhaps the most common pattern) while others have all 2's, 3's or 4's. Second, assuming dealers are in on the tampering indicator, it would also render more understandable the French dealer's seemingly stubborn refusal to approve Cayman Driver's lease return with all 1's in the upper ranges. Finally, I happen to know of someone who had an aftermarket re-flash, and subsequently had an over-rev report involving all 1's in the upper ranges.

All of that is admittedly very slim "evidence" supporting your theory, but it could be just a start, assuming self-report data on over-rev counts could be gathered from owners who have, and have not, "tampered." The over-rev anomaly puzzle could be just the one that we need to replace the "blue paint engines" puzzle, now apparently resolved.

For the "untampered" category, my own ignitions count is 3559 in Range 1, and zeros in the other ranges.