Explanation of a DME report 996 turbo?

Sure,

So Range 1 readings are electronically limited over-revs. They are safe, and limited by the factory rev-limit.

The "8322" is how many there are (a count), the "1171.1h" is the engine operating hours that the last recorded over-rev occurred.

Looking further the "8322" is actual ignitions that have been recorded. That means that 8322 ignitions occurred to date in that over-rev range. That is not too bad. Here is why: Ignitions happen in micro-seconds. So 8322 ignitions equals maybe a few seconds. Not a big deal. I have read ranges with 30-50 thousands range 1 ignitions. Its no sweat.

Now, Range 2 is much more important. And to have 2236 Range 2 means that someone went beyond the electronic rev-limiter. How do that do that? Go beyond? Well, often times its a missed shift, or a downshift at too high of a rate of speed for the next lower gear.

Range 2 is a warranty killer. You have 2236 Range 2 over-revs back in 2005 and ask Porsche to warranty your engine? Nope. Your loss.

Now here is the rub.

This is how I read this - This car has a total of 1171.3 operating hours. And the last over-rev recording both Range 1 & Range 2 are at 1171.1 hours. Can you see that by reading this how I would extrapolate that within just minutes of getting this report (1171.3 hours) someone beat on the rev-limiter right beforehand (1171.1 hours).

Either someone test drove it that did not know how to drive a manual, or maybe some valet was whipping it on the way to the Porsche workshop.

I hate that when that happens.

 

Yes, 2236 is limited time at Range 2. But keep in mind that most of the time I see no more than say 200 - 400 Range 2.

Seems pretty simple to me how it happened. Been at dealer for a while?.. Plenty of test drivers. Failure in the shifting department.

 

Here's how to calculate seconds in the ranges:
6 cyl 4 stroke engines have 3 "ignition events" per revolution (6/2). I believe the range 1 and range 2 limits for an '05 Turbo are 6,750 and 7,250 respectively. So...

Range 1: 8,322/3 = 2,774 revolutions. (2,774/6,750)*60 = 24 seconds in range 1
Range 2: 2,236/3 = 745 revolutions. (745/7,250)*60 = 6 seconds in range 2

I would be concerned that the most recent range 2 over-revs happened only 0.2 hours ago (12 minutes ago) which is only about 8 miles ago at 40 mph avg speed.
One of the problems with the earlier DME reports is that they only have two ranges, i.e. you don't know if those range 2's were 7,300 rpm or 12,000 rpm. With the 997 series the DME reports were expanded up to 6 ranges which gives you a much better understanding of the nature of the over-revs.
Once this car has a few hundred miles under its belt and passes compression and leak-down tests I would be less concerned about imminent damage, but I'd give it a pass for now.



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