HELP! Type 2 Over Revs Make Me Very Leery About My Dream 996tt

[NineElevenLover]

I was ready to pull the trigger on this car and go pick it up tomorrow. It's a 2003 with only 9700 miles.

http://www.cars.com/go/search/detail.jsp?tracktype=usedcc&csDlId=&csDgId=&listingId=55832326&listingRecNum=2&criteria=sf1Dir%3DDESC%26mkId%3D20081%26stkTyp%3DU%26mdId%3D20567%26rd%3D250%26crSrtFlds%3DstkTypId-feedSegId-mkId-mdId-prcId-trId%26zc%3D20171%26prcId%3D28569%26rn%3D0%26PMmt%3D1-1-1%26stkTypId%3D28881%26sf2Dir%3DASC%26sf1Nm%3Dprice%26sf2Nm%3Dmiles%26trId%3D25704%26rpp%3D50%26feedSegId%3D28705&aff=national

The appointment had been set and it was essentially a done deal, pending a diagnostic check at a local Porsche dealership to pull the codes from the ECU to see if it had ever been moneyshifted. The results were quite unsettling....

Type 1 - 7830

Type 2 - 364

The tech who did the diagnostic inspection at the local dealership was telling me that it was no big deal. I called a couple local ones, however, that seemed to think it was rather significant. One, in particular, I called and spoke to the service manager. He seemed to think it was alright and I should go ahead with the purchase, but then he decided to put me on hold and speak with one of his techs/mechanics who was more familiar with the over rev codes. When he came back, he essentially said "I'm glad I went to ask my tech, because he seems to think it's a very high number and you're taking a big risk." That did not sit well with me at all. *sigh* I guess I'm no longer interested. So disappointing. :(

I'm planning on modifying this quite heavily, so I must have a rock solid foundation from which to start. I moneyshifted a car of mine back in the day at the dragstrip, with no immediate resultant problems. About a year later, however, the engine had an absolutely catastrophic failure. I can only assume that it was caused, for the most part, by the moneyshift, as a rod bent and subsequently exploded almost the entire bottom end.

What do you all think?

[Dus10R]

The 364 number is the amount of times the engine fired in that type II over rev situation which is a down shift over rev situation... which means it's around 2.8 seconds or so of over-rev. Personally I wouldn't worry about it. These engines are being modified to run 600+ hp with stock internals so the internals are pretty **** tough. Now I don't recommend type II over-revs all the time but I don't think it should be a deal breaker. Just my .02 cents.

[jpflip]

Dus10R Let's figure that out. On a four stroke engine you got a spark every 2 revolution of crankshaft. Means 6 cylinders = 3 spark per revolution of crankshaft , So 364 divided by 3= 121.33333.... So we had 121.3 revolution of crankshaft over 6750 RPM. So if I got 6750 revolution in one minute that means 112.5 revolution in one second ! Do you agree with me while I am thinking loud ;-) If not please don't hesitate to correct me. But because we are in overev situation , may be 6800 or worst 7000! This condition last less than 1 sec. Ouch I need a break....

Edited February 17, 2011 by jpflip

[1schoir]

You can get some additional information from the ECU which you might find useful in making your decision.

There is data available which tells you the total number of hours that the engine has been in operation, usually listed as "operating hours counter".

Then, following the number of "overrevs" of each type (i.e., Type 1 and Type 2, in the case of a 996TT 6750 to 7250 and 7250 and up, respectively ) there will be a figure followed by a small "h".

The figure that is followed by a small "h" will tell you at what operating hour the LAST overrev of that type occurred.

If you compare the figure for the Type 2 overrev with the total operating hours, you will learn how recently (in terms of operating hours) that happened.

The operating hours can also help you determine whether the mileage reflected on the odometer is "real". You can take the mileage of 9700 and divide it by the number of hours that the engine has been in operation. That will give you an AVERAGE miles per hour figure. If the figure is far outside the range of 30 to 50 mph, I would have some reservations. If it falls squarely in that range, it might increase your confidence factor.

Let us know which way you go...and don't forget to post photos when you finally get one!

Regards, Maurice.

[NineElevenLover]

I just got back from an 11 hour round-trip visit to go see this car. I had to at least test drive the thing, or else I would have been constantly wondering if it was "the one that got away." I estimated that there was about a 50/50 chance I would be driving back in a Porsche. Once I arrived, I looked the car over; it was extremely well-kept, inside and out. The engine looked clean, and the only real issue was two scraped-up wheels. One wasn't horrible, but the other one was definitely substantial. Not so much a deep gouge, but a lighter scraping that extended almost the entire way around the edge of the wheel.

I first let the car idle for about 5-10 minutes. It started immediately and the motor sounded very nice. It idled purrrrfectly and I was pretty impressed at this point. I took it for a nice and long 20 minute test drive, with a mix of city driving and highway driving. The engine felt nice; smooth and powerful, but a bit slower than my current 335xi. The car tracked straight and smooth, and everything felt pretty solid.

Then the first problem arose: I was downshifting from 3rd to 2nd, clutch fully disengaged, perfect heel-toe rev-match, and the tranny made a grinding noise when I attempted to move the shifter into 2nd gear. That did not sit well with me at ALL. I kept driving and then the second, relatively minor issue became apparent: it was slightly difficult to get a smooth shift into 3rd gear. No grinding, but just not smooth engagement like the other gears. I kept on going for a few more miles, then needed to make one last u-turn before ending the the test drive. I was at a red-light which turned green, so I depressed the clutch pedal, shifted into 1st gear, and began to lift the clutch pedal to start moving. The instant the clutch started to engage, the shifter popped out of 1st gear into neutral. Ugh...

Needless to say, I made the five and a half hour trip back home in the same truck I drove up in. I wasn't so much disappointed as I was relieved that the problems had manifested themselves, otherwise I may have made a very bad purchase. I feel as if I absolutely made the right decision here. Oh well, I'm sure there will be plenty more nice cars in the future.

[Danyol]

IMO, I would have expected the inspection to find the transmission issues, lucky you were thorough with the test drive.

I would have been less worried about the Type 2s but the duration and the low mileage of the car throw a red flag. Added to that a transmission issue (most likely clutch, soon to be gearbox) indicate an "unloved" vehicle that's had abuse. If you were looking into the car further the suggestion on the operation hours is a good one, but with such low mileage problems may not show up yet.

Scr... the low mileage and walk away, lots of cars out there that have been well cared for, if you're looking for low miles I'll share a little from my last oil analysis. At 32k miles some of the trace elements were consistent with early life "break in" of the engine, that made me smile!

I just got back from an 11 hour round-trip visit to go see this car. I had to at least test drive the thing, or else I would have been constantly wondering if it was "the one that got away." I estimated that there was about a 50/50 chance I would be driving back in a Porsche. Once I arrived, I looked the car over; it was extremely well-kept, inside and out. The engine looked clean, and the only real issue was two scraped-up wheels. One wasn't horrible, but the other one was definitely substantial. Not so much a deep gouge, but a lighter scraping that extended almost the entire way around the edge of the wheel.

I first let the car idle for about 5-10 minutes. It started immediately and the motor sounded very nice. It idled purrrrfectly and I was pretty impressed at this point. I took it for a nice and long 20 minute test drive, with a mix of city driving and highway driving. The engine felt nice; smooth and powerful, but a bit slower than my current 335xi. The car tracked straight and smooth, and everything felt pretty solid.

Then the first problem arose: I was downshifting from 3rd to 2nd, clutch fully disengaged, perfect heel-toe rev-match, and the tranny made a grinding noise when I attempted to move the shifter into 2nd gear. That did not sit well with me at ALL. I kept driving and then the second, relatively minor issue became apparent: it was slightly difficult to get a smooth shift into 3rd gear. No grinding, but just not smooth engagement like the other gears. I kept on going for a few more miles, then needed to make one last u-turn before ending the the test drive. I was at a red-light which turned green, so I depressed the clutch pedal, shifted into 1st gear, and began to lift the clutch pedal to start moving. The instant the clutch started to engage, the shifter popped out of 1st gear into neutral. Ugh...

Needless to say, I made the five and a half hour trip back home in the same truck I drove up in. I wasn't so much disappointed as I was relieved that the problems had manifested themselves, otherwise I may have made a very bad purchase. I feel as if I absolutely made the right decision here. Oh well, I'm sure there will be plenty more nice cars in the future.

Edited February 20, 2011 by Danyol