accelguy

I have viewed a 2005 997 C2s MT with the following records

ignition rev 1 640/1663h
ignition rev 2 63/1663h
ignition rev 3 4/1663h
ignition rev 4 4/1663h
ignition rev 5 3/1663h
ignition rev 6 2/1663h

Total engine operating hr counter = 1674h

I desperately need some advice as to if this car is safe to own for many years if I do not plan to over 7000rpm at all. Will the records in rev 5 & 6 = a walk a way from the buy situtation?

Many thanks for your kind assistance.

James

Bruce In Philly

I would pass for two reasons: 1) there are better cars out there, 2) the bad shift occurred recently.... no time on the engine to really know if there is damage.

Regarding my opinion on 2 above, I acknowledge that is just emotional as I don;t have the knowledge to fully understand the implication of this. But number 1 trumps all.

Peace
Bruce in Philly

Macster

The overrev counts for ranges 5 and 6 look implausible to me though I can't supply any real logic for why this is so other than the numbers just don't look, well, plausible.

I have felt that the overrev counters are in some way protected by some software mechanism to allow Porsche to detect tampering.

Whenever the car is connected to a Porsche diagnostic computer the DME is scanned and I'm sure the overrev counters are read out and these along with a number of other things the DME (and other controllers) has (have) stored/accumulated are sent back to Porsche.

Thus I suspect that low counts in the higher ranges are just signs that these are written with some non-zero values that Porsche can use to know if these were tampered with.

Anyhow, even if you assume the numbers are real I note the time they "happened" was at "1663" hours. The total engine run time is now 1674 hours.

So the engine has run 11 hours and I assume a thorough test ride/drive didn't turn up any scary engine sounds, any scary engine behavior, the CEL light works but is dark after the engine is started and remains dark all the time during the aforementioned test ride/drive?

If so the 3 and 2 in the 5 and 6 overrev counters wouldn't put me off the car.

But you have to go with your gut feeling and if you don't think you like the numbers and knowing they were there would bother you I'd say then walk away.

There is always another car.

accelguy

Yes the CEL light remained dark after a 30km test drive. I also hv date of another 05 C2s MT

Is this a better buy based only on the DME data?

ignition rev 1 20982/2225h
ignition rev 2 3189/2225h
ignition rev 3 499/2225h
ignition rev 4 90/647h
ignition rev 5 0/0h
ignition rev 6 0/0h

Total operating hour 2439h

rickdogg82

I feel that the first one is better. Second car has seemingly been driven hard a lot of its life and has more miles.

The first report does not appear to be completely correct. I don't believe it is possible to have a 2 reading for range 6 and a 4 reading in range 3.

Hella-Buggin'

It's mechanically impossible to have that reading for real. It needs to be a defending reading from range to range. The engine can't go from 9000 RPM to 7000 RPM instantly.

kk2

I'd stay away from both.

Hella-Buggin'

In general it looks like someone drove it nicely without incident for a long time, someone didn't.

Quadcammer

first one is a dme "glitch"

You can't have 4 in range 4, 4 in range 5, and 3 in range 6.

rodH

I am just starting to pay more attention to these threads.

Can anyone briefly explain what the different rev counts mean and how this is done?

I have hit my rev limiter a few times, but it then cuts ignition so one simply gets off the gas. How does one go into these high ranges when it should cut the ignition?

jhbrennan

This topic get's discussed as often as what oil to use so a search will probably give you the explanations you want. A mechanical over-rev (mis-shift like a hi speed run up through the gears and you go from 5th to 2nd when you were trying for 6th) will get you into the ranges higher than where ignition cut-off comes into play.

captainbaker

This article explains is fairly well in a compact fashion.

http://www.911virgin.com/porsche/rev-range-information/

Macster

Agree with this.

rodH

Oh, wow, so this are major screw ups or people that just don't know how to drive. I don't think I have done that more than 1-2 times in my lifetime driving a MT for the past 30 years.

Bruce In Philly

I am not so sure about this....... It counts "ignitions" and not revolutions in some band .... what if you let the clutch out but don't apply gas... and shoot the RPMs up into band 6? Most computers are smart to cut gas for mileage if nothing else. When you car coasts down a hill, you are in gear and you let off the gas and coast, the computer cuts gas..... so no ignitions????

I have tracked live values from my Durametric and the car accuratly tracks RPM, digitally. Why doesn't the computer track RPMs in these higher bands and only "ignitions"? If the engine is spinning in an upper range in a danger zone, why doesn't it just track RPMs and time? The data is certainly there.

This may be more complex than we think... the computer may be exactly correct and functioning properly. The problem may be in our understanding.

Peace
Bruce in Philly