<o></o>Hey guys. Looking to purchase a used 07 997TT. I just received the DME report today and have Range 3/4 over revs at what seems to be low (likely break-in) hours. What do you guys think of this report?

<o>Miles: 5,800 / 6-spd manual</o>
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Range 1 - 2393 / 219.6h
Range 2 - 210 / 218.3h
Range 3 - 25 / 15.7h
Range 4 – 4 / 15.7h
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Total hours: 223.00
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Any insight / opinions are greatly appreciated. Edit: I may also mention that this car is CPO'd.

 

A previous owner over rev'ed to range four during the initial break-in period. If the average driver has a usage rate of 25-30 miles/hr during the first several hundred hours of use, the over revs came with in the first 500 miles of use. You'll get plenty of opinions whether or not this is bad.

- bob

 

Thanks Bob. If you don't mind me asking, what would be your opinion? How crucial do you think the early (brief) over revs are? I guess a positive would be that it has not had a 3 or 4 over revs for most of its life? Of course, it most likely had 1 and 2 over revs during break in as well? Tough call for me to make.

Appreciate any feedback. Thanks.

Brian

 

If the car was able to be cpo-ed then it can't be that big of a deal, right? The actual amount of time in an over-revved state is quite small. If it were me I'd still think about getting the car if it had everything else I wanted for a good price. The one I got actually had only 4 stage 2 overrevs and nothing higher so clearly it was grandma driven.

 

Brian, two schools of thought.

One school - there are many 997TTs out there. Far more than what current demand is. You can probably find one with the same options with no over revs.

Other school - Single over rev like that is probably okay. GT1 blocks are dyno tested before installation and are broken in prior to leaving the factory.

My only worry isn't the engine, but some concern if the original owner showed such little concern about the car, was anything else abused? As long as you get a PPI, you're probably fine.

- bob

 

Thanks Bob. With the only type 3 and 4 over-revs being that long ago at 15.7 hours (at exactly the same time), maybe it was a downshift boo boo when he was just getting used to the car? No 3 or 4's at all in the last 200 hours... I am not an expert in the calculations, but am I correct that the 3's and 4's were less than a millisecond?

 

Pretty short.

Around 7000 RPMs, there are 350 ignitions per second.

So, we're talking about 70 milliseconds in range 3, 10 milliseconds in range 4. Pretty small, probably from a crappy down shift.

 

Should be still within the safe engine speed range. Not sure on the 997TT, but I know the M3 has a redline of 8300 RPM's, but the safe engine speed is actually 8800 RPM's.

Again, assuming a 30 mph average the car was in the 450 mile range. So for everyplace else in the world except the US the car was broken in according to the ROW manuals. Porsche does not want to listen to complaints from US buyers about excessive oil consumption.

 

When you read type of over revs have in mind that anything BEYOND type 4 is bad...until type 4 is ok...it is obvious that there has been a downshift by mistake...And only one...So he is a good owner...Over rev types are explained as follows for the turbo engine of 997TT...
Range 1 - 6800-7000
Range 2 - 7000-7200
Range 3 - 7200-7400
Range 4 - 7400-7900
Range 5 - 7900-9000
Range 6 - 9000 up

 

Thanks for the input guys...I came across another DME like this:

Range 1 - 1 / 65.1h
Range 2 - 1 / 65.1h
Range 3 - None
Range 4 – None
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Total hours: 433.00
~15K miles

I thought ranges were cumulative? Shouldn't there be a "2" for Range 1 since it hit Range 2? Also, can't believe the lack of over-revs with 15K miles...is this for real?

Brian

 

I have seen over-revs like this very early in the cars life time many many times. Sometimes it even happens when the sales man was sitting in the drivers seat free revving it to show off the sound to the potential buyer. It is so easy to free rev it up into the limiter, and the inertia of the standard flywheel will carry it up and over easily... It does not sound harmful even to the potential buyer, but the ECU certainly logs the data..

We see it often right after a customer has a new Tubi or equivalent exhaust system installed, they sit and free rev them to show off the sound.

I would not worry about it. We just don't see failures with these engines. This is an engine that can be pushed to 6 or 700hp up and over 8000 rpm and maintain relaibility.

Good luck with it..

 

when i first purchased my car i was getting to know it i am sure during the breakin periode i missed some shifts and other small mistakes causinng some over revs i dont three or four means anything exspecially with the rev limiter