Over Rev reports

Hi All! I am in the process of purchasing a 2008, Carrera S, 6speed Manual. i have had the car condition checked and had them run an Over Rev report (see below) i have no clue what i am looking for in the reports and what would deem the report to be satisfactory or not. i do understand that rev's in the range 4 and up are not good??? any thoughts guys?

Anything above range 3 is not good, and 212 revs in range 5 is a very questionable sign. Warranty coverage would probably be denied by any dealer that saw this. Range 1 and 2 can be generally ignored.

RUN AS FAST AS YOU CAN! As was stated anything over Range 3 is typically an AUTOMATIC WARRANTY DENIAL Then again, it's a 2008 with little warranty left if any, so it may just depend on how much risk you want to take. See if they will CPO the car. :hilarious:

Thanks for the replies people! There is no warranty left, the car has 50k (kilometres) am i just beimg unwise in buying a car that has had these range 4 and 5 numbers, what does it actually mean to have in Range 5....is the engine life dramatically reduced?

Range 4 is 7900 to 8399 RPM Range 5 is 8400 to 9499 RPM The redline for the 3.4 non DFI engine is 7300 RPM. Definitely a mechanical overrev due to a missed downshift. For reference, Range 3 is 7700 to 7899 RPM.

Thanks Pistol This is for the Carrera S i may be buying, i have now sold the CS you see in the picture. are the Rev Ranges the same? and am i right in saying that if he has 212 hits in Range 5 then there has been 212 missed shifts, or is it time reflected? thanks.

Missed shifts are called "money shifts" for a reason. The rev limiter prevents the engine from over speed via the gas pedal, but a missed downshift (say from 5 to 2) will mechanically over speed the engine and potentially damage the internals from pistons, crankshaft, to valve train. There seems to be no good reason for you to want to purchase this car as there is a definite possibility of serious mechanical damage having already occured within the engine.

Thanks Dave. The experts have assured me that due to the over rev being a considerable amount of time ago that there is slim chance the Engine is mechanically unsound, however just to be sure i am having a compression test and something called a leak bell test (not sure of the right term) this will determine if indeed the engine is Kaput....

Sorry, it was 1:30AM and I wasn't reading too carefully! I don't have the 997 numbers but the concept will be the same with respect to the overrevs. As far as the numbers go, I'm told they are "ignition cycles" followed by an explanation of how 3 sparks is considered a cycle, etc that made my eyes glaze over. In any event, the number doesn't mean the number of times it's been over-reved. Maybe some of the more mechanically astute on board here will provide a better explanation. The time shown is basically when in time this occurred with the starting point being the first startup of the engine (at the factory I assume).

I would pretty much concur with the rest of the group,....I would not even consider unless they did a CPO on the car, just too much risk vs. reward here. A compression and leakdown test may come back fine, but it won't tell the whole story in regards to stresses the engine has endured. In other words the engine may last 10k miles more and then break a rod, rod bolt, etc. So, the longevity of the engine could be in danger, not the present running condition.

OP you really don't need the headache... There are plenty of Porsches in good condition out there. Obviously they're giving you a good deal... It won't be worth it when you pay $1000s down the road to fix the inevitable. If you insist on buying it, then check the cost of engine rebuild and new engines prices. Because you'll probably be adding it to your bill soon. Good luck!

What experts? Someone out there think they know more about this stuff that WE do?? :hilarious: As Pete explained it has to do with the number of ignitions and given the relatively low number it was probably a single missed shift, possibly 2 at most. The fact that it happened a long time ago is irrelevant to Porsche in terms of warranty coverage but as you said you aren't concerned about warranty coverage. It IS RELEVANT in terms of potential engine damage. A leak down or compression test will not tell you if your bearings are about to spin. A leak down or compression test will not tell you if your rods have been stretched or your rod bolts are about to fail. Typically those tests will only uncover whether or not your rings are good/bad, cylinders out of round, etc. none of which happens with a missed shift. You might have marginally bent valves that produce an occassional misfire or will lead to early failure, again those tests won't tell you that. I wouldn't buy this car without SOME sort of warranty, guarantee that if something goes bad with the engine within X period of time that your problems will be covered. Your engine might have very little damage from the incident and lead a long and happy life, or it might crater next week. No test is going to tell you which is the case, only an engine tear down would tell you.

My understanding: The numbers in each over-rev range are ignitions (firings), they are cumulative for each range, and there are 3 ignitions for each engine revolution. The Range 4 and 5 ignitions (the ignitions of greatest concern) all occurred at the 603.4 hour of engine operation. But the engine was over-reved into Ranges 3, 2, and 1 at other times more recently. The 14,544 total ignitions in Range 1 (a range usually of little concern) suggest that the rev-limiter has been called into action quite a few times. The engine has been in operation for over 300 hours since reaching Ranges 4 and 5, so it's possible that no permanent damage occurred. I'd still pass on this car, however.

If my math is correct, at 8000 RPM there are 125 engine revolutions each second. Given that assumption, and 3 ignitions per revolution, 212 cycles would indicate approximately 70 revolutions or the equivalent of more than 1/2 of a second in the range 5 danger zone. No other information should be necessary to convince you that this is not an ideal purchase. Plenty of other fish in the ocean.

Thanks for all your help guys, gonna walk away from this one, out of interest b elow is the findings from the compression test. thanks again everyone, this forum rocks!!!! Cylinder 1: 90 17.5bar Cylinder 2: 93 17bar cylinder3: 94 18bar cylinder 4: 92 18bar cylinder 5: 85.5 18bar cylinder 6: 86 18bar when the engine is cold: Cylinder 1: 91 18bar Cylinder 2: 93 16.5bar cylinder3: 94.5 18bar cylinder 4: 92 17.5bar cylinder 5: 84 18bar cylinder 6: 94 17.5bar

Just saw your PM and this post. Like others I'd walk away as there are plenty of other 911's out there. The reality is that there has been a significant time between those over revs and the point at which the car is at now. So it's likely there is nothing wrong, but why take the risk when you can find another car which you can have that extra piece of mind with. Let me know what specs you're looking for and I'll keep my eyes open for you. :cheers:

Out of curiosity, how do you obtain the over rev report? Only at the dealer, or can it be retrieved via Durametric and Handheld Scanners?

The Durametric Pro tool will show you the overrev report. I'm not 100% sure if the basic version will do that, can someone confirm? The dealer PIWIS tool will show this as well.

You guys are just the Mutt's Nut's!! Without this forum, i would have potentially bought a car with questionable engine life, i loved the car, exactly what i was looking for (well not really, GT2 RS, but waaaaay too pricey) so, im back on the hunt.., thanks again all!

Please consider supporting this forum with all the $$$ you just saved! :kiss:

Durametric Enthusiast Version will provide overrev report as well.

Soon to be unveiled GT3......

Haha!!! Now that's better than hitting the jackpot Just please make sure it's not white, or I'll hate you for that go for yellow, red or black

Haha, Hassan......it's official, you hate me!!! Do you hate me more if I told you it was mint, CCB's, Alcantara, SC etc.....

First of all congratulations for housing a beast... may you enjoy it safely inshallah. Second thing, oh yes... I hate both you & white Porsches Last thing, when you post her pictures put a warning at the thread's title that it's white Enjoy it buddy... You made my day

Just waiting for the bank to pull its finger out, should be transferred in my name by the end of the week....Inshallah! Haha, with the graphite grey alloys, in white exterior....its a stunner....

Hassan, how can you hate me for this....

It could be only me but I don't like white cars (btw I have a pearl white Land Cruiser, that I regret)... They look like washing machines! The only exception is the GT3 RS 4.0 that I drool on. IMO GT3 looks best in yellow or red. If not then black. But hey! As per the Arabic saying "when the fox can't reach the grapes, he call it '7sorom'" Enjoy it my friend... Who cares what a Cayman owner says

I have the Durametric Enthusiast cable, attached is my report

Never seen one so clean before!

I got lucky Ken, didn't check it before I bought the car. It seems the previous two owners took excellent care of the car, and I continue to lavish much praise & attention on her. I bought the Durametric to clear some codes and got playing around with it, a very valuable tool to own for quite a modest price.

Hey Dan. Thanks Buddy! Yeah, lets catch up for a beer/shisha/coffee. you free Tuesday? PM me your number again, lost my phone a while back, with all my numbers! Hassan, what dates you gonna be here?

Thursday, Friday & Saturday this weekend inshallah.

cool, Dan, Hassan lets all meet up next weekend, preferably late afternoon Friday or on Saturday.

Is there a strip anywhere, that would enable two Caymans and a GT3 to sit alongside, the strip should be at least 1/4 mile long.....