DME Vehicle Data Questions -

[bryanearll]

I've said before that I've had a recurring problem with 2nd gear popping out. I had the car in at the dealership today looking at linkage issues, that didn't seem to be the problem. Of course, it wouldn't "do it" it for the tech.

STILL, I LEARNED SOMETHING VALUABLE... Now if I can just have someone explain exactly what it means please:

911 (996) DME Vehicle data
Number of ignitions, range 1
6254 - - - - 1250.8 hours
Number of ignitions, range 2
101 - - - - 41.2 hours
Operating hours counter
1255.7
Type ID DME control unit
996US020
And some other stuff like VIN number, paint, etc.

The missing data I'm looking for is:
1) why is there a discrepancy between total operating hours and hours within the two ranges.
2) I assume that the number of ignitions is in 000's
3) I'd like to know specifically the rpm ranges in question, if anyone knows.
4) What is the bad number or ratio when Porsche says: "you've been ragging out your car and that kind of use is abuse. No warranty."

I spoke with the dealership and they were willing to perform the test again (it's about a 5 minute test) in a couple of weeks. I'll get another AX in and see what the differences are in the data.

I'm interested for several reasons:
1) I bought the car used.
2) Warranty issues.
3) Understanding the data may help you maintain your engine longer.

If I'm allowed to speculate (just to see where I'm wrong), I'd say that Zone 2 is above 6000 RPM, though it might be higher. Currently it would represent 3% of use, including some "mystery hours". I would speculate that the missing 36 hours is factory inspection, break in, testing. If that was the case the RPM figure in Zone 2 might be "the red line".

This might be important because I have had several people say it's OK to hit the rev limiter, that's what its there for. Mechanically, that might be the case, but to Porsche who's judging your abuse of the vehicle you might be shooting your warranty in the foot.

So please explain the mystery, and in two weeks lets look again at the data.
Bryan

[David J Marguglio]

Bryan: I knew one, had to check on the other. The jumping out of second gear is a problem with some 996's. Unfortunately, I dont think there is a cheap or easy solution. Basically, the box needs to come apart and is partially rebuilt. I am not sure if a dealer will do that or not (they tend to think think of these as disposable). However, I know that Mind Over has resolved that problem for at least two 996's including a twin-turbo. You will have to speak with Tim when he gets back from Daytona for the specifics.

On the DME data question, Joe Leggs at MOM informs me that the operating hours counter is the total number of hours since new. Range 1 and 2 are over-rev situations. Range one, is up to and including the rev limit, "6254" is the number of ignition cycles that the engine operated at that over-rev and the "1250.8" is when is occured in the life hours of the car (so it was very recent). Range 2 is an extreme over-rev situation (I believe it above 7500 which would likely only occur on a missed shift) the last one had a 101 ignition cycle duration and occured at 41.2 hours (so before you owned it).

Hope this helps.

[bryanearll]

Thanks David for getting the information from "MOM".

Doggone rat old owner. Now this is a test that I will definetely have done before I buy my NEXT used Porsche.

The good news is that the technician said that the number was very low on the REV 2, he had seen much worse.

I hit the Rev limiter at the December AX and, of course, at the driving school. At this past AX I didn't hit the limiter but it is clear that I went high enough to be in the "bad" range of Zone 1.
If you can find out from "MOM" where Zone 1 first engages that would be worth noting. If this is how Porsche keeps you honest on revs, it worth staying under that where possible. Avoid the argument later. I'd also like to know if the ignition cycles are cumulative or a record of the last event.

Doggone miss shifting rat former owner.
bryan

[bryanearll]

I posted a similar question on Rennlist and was answered by Loren...

The only one you need to worry about is stage 2 (over-revs). Stage 1 over-revs are fine since the rev limiter protects the engine - these are acceleration over-revs. The range 2 over-revs are potentially engine damaging since these can not stopped by the DME or other means. Range two over-revs are usually caused by a bad downshift forcing the engine to over-rev (without any control) or by spinning the car and running the engine backwards (because the clutch was not depressed in time).
A normal number for range 2 is 0.
__________________
Loren
Rennlist #020607-2749
1999 Carrera Arctic Silver/Boxster Red
PCA member since 1978