jeffmeunier

Looking seriously at a car, but interesting PPI report history
(Sorry for cross-post, just joined and didn't notice my other post was a tag on the GT2 forum)

- Being sold by dealer, according to them a tradein from a local regular customer.
2003 996tt with 21k mi
Type I: 3956 / 375.9h
Type II: 317 / 704.7h

Here's the interesting part: op hours 704.9

So the Type2 event was very very recently. Maybe a case of someone doing something stupid once the dealer got it. Or (my main concern) is this a car that could have had a rough experience and is getting dumped because it's not healthy?

The car is 2.5hrs away from me, so I can't go easily do a quick once-over. I will want to have it PPI'd remote before driving all the way out.

Questions:
- red flag for any of you, or still worth taking the next step of paying for a PPI?
- If I decide to pay for a PPI, is there anything specifically I would want done to verify engine is ok? I've read to have a compression test and/or leakdown test done? What about dyno test? Or, if the event was that recent would these tests still clear since enough time hasn't passed?

I'm new to the group, looking to buy my first 911, and doing as much research as I can. Would greatly appreciate any pointers. Thanks!

"02996ttx50

it's always something stupid once the dealer ( could even be the manager, for what does he care ) gets a hold of them. either that or a test drive.

those type twos arent enough to dissuade me at all, nor indicate a condition of ill health. go check it out. good luck!

rmc1148

I see a lot of over revs while a car is in the for sale mode lol. Someone with more experience with the over rev data will chime in. I would inspect the car personally and have a good shop check it out= get their opinion on report. Curious what they are asking?

leftlane

Is the car tuned?

Macster

Type 2 over revs in the 996 Turbo means RPMs exceeded 7250 RPMs. (Type 1 over revs range from 6750 to < 7250.)

My WAG is a test driver - customer or even a dealer employee -- made a money shift.

So, I would be inclined to give this car a miss.

Here's a link on over revs and one that has a story about an over revved engine that someone bought and the engine developed issues after a few hours worth of run time after the over revs.

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

The take away from the story at the above site is it can take time for the effects of an over rev to make themselves known.

You can visit the car and subject it to an hour's run time as you start the engine and let it idle then have the seller take you on a 15 mile test ride followed by you then test driving the car following the same 15 mile route.

But an hour might not be enough run time for the after effects of an over rev event to make themselves known.

Given these engines are super expensive to have rebuilt to deal with over rev caused trauma I'd walk away.

Remember: There is always another car.

Tuxiemama

317 type 2 is nothing... a few secs....

Macster

It is not the duration of the event but that the event occurred at all that is the issue, the concern.

The concern is the engine speed surpassed the valve springs' ability to control the valves and valves and pistons met. In a severe over rev event one can know something happened almost immediately if not immediately.

But if the event was not severe while one or two valves got slightly bent, they still seal or seal well enough at low loads but some hard runs can have combustion gases leaking past the valve/valve seat and the valve and seat can only go down hill. After a while then the valve/seat leak all the time and persistent misfires are the result. No combination of new plugs, new coils, a new MAF, new fuel injectors, fuel system cleaner, etc. will cure these misfires.

Or the bent head results in a mechanical failure. After some engine run time the head separates from the stem and the head then is loose in the combustion chamber/cylinder.

jeffmeunier

Trying to get more details from the original owner via the dealer, but I don't have info on this car that indicates it's tuned.

That 911virgin article is about the best treatise on over revs that I've seen on the group, thanks for sharing. A little on the conservative side, but when it's your own money or reputation on the line it's understandable.

I'm going to talk to the local 3rd party shop I'd have do the PPI on their recommendation and the ability to do a compression test. Seems like the best I can do with the info at hand, will let the group know what I decide and any other info.

Atrox

Just get a tiptronic problem solved. No over revs, no clutch to replace, no slave bs, and you can readily eat a snickers while driving.

Tuxiemama

No it is generally not a problem.. my car even with the limiter at 6800 registered several type 2 events and now I have a highly tuned car with a 7300 rpm rev limiter...

what matters is how the car drives, how the rest of the Durametric reads... whether plugs, coils, oil have been done anytime recently... how the radiators are.. whether there are any clutch problems... are there any visible oil leaks... is the PPI guy competent..

is the car tuned and by whom.... what is the IDC% when the car is thumped... does it have any obscure engine ticks or noises.. are there ay boost leaks...


Is there a new MAF or a cleaned MAF ad infinitum

ETC

wross996tt

and be bored to death while not enjoying the thrill of shifting...LOL

Macster

Not quite apples to apples.

In your car's case the over revs are while higher than stock are still limited from the higher rev limit setting.

IOWs, the over revs are not due to a money shift and have not substantially exceeded the new and higher rev limit. Thus there is some confidence the over revs your engine has experienced have been just at/over the new higher red line.

In the case of the car the OP is looking at the over revs are not from a tune and its bumped rev limit but from a "money" shift. We do not know the RPMs obtained but almost certainly they were a ways higher than just at the #2 range limit.

Furthermore, while there is some margin to be sure in the OP's case the engine experienced over revs just very very recently.

The techs have told me that absent any signs of any issues from an over rev event they like to see an hour's engine run time -- and run time that involves more than just idling or tootling around town is necessary -- with no signs of any engine distress from the over rev event before they feel comfortable the engine didn't suffer any from the over rev event.

But I'm getting a bit more cautious and I'm not sure I could live with just an hour's engine run time.

However, it is up to the OP of course what he can live with. If he is comfortable with say around an hour's engine run time as he checks out the car and the engine is still in fine fettle after this hour that's his call.

Tuxiemama

I understand, thanks

ANJ-911

This may be a dumb question, but does the 317 type 2 over-rev reading mean that the car has been over-revved 317 times in excess of 7,250 rpm, or is the 317 a different unit of measure?

Also, how can the latest type 1 over-rev be at 375.9 hours and the latest type 2 over-rev be at 704.7 hours? Wouldn't a type 2 over rev trigger a type 1 over-rev since you likely travelled between the 6,800-7,250 rev range on the way to the type 2 over-rev? Or does it just register a type 1 or type 2 over-rev depending on what max rpm you hit?

Vendetta NY

It means there were 317 ignitions above 7,250RPM. Let's assume for discussion's sake that the ignitions happened at 7,300rpm. The formula I've seen used here (but of course I can't find it now) is:
7,300 / 60 = .008RPS(econd), and there are two ignitions per revolution so
(317 * .008) / 2 = 1.26 seconds worth of ignition in range 2.

Not a lot at all, unless it was that one money shift.

Mine had 323 ignitions in range 2 when I purchased it. But, there were like 20 hours on the clock since the last event. I'm pretty confident I've added a few more since.

Good luck, OP. Personally, I'd let the car age a few more hours and have it looked at, just for peace of mind. But I wouldn't be surprised when they find nothing.

-V