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Posted

Searching for an answer.

Driving a 2006 Boxter, 2.7 , 5 speed with 40K. I am an experienced driver with 40 years of driving manual transmissions hi performance sport cars.

After acceleratiing from a stop sign, first gear to 4000 rpm, shifted to 2nd gear up to 6700 rpm then upshifted to 3rd gear to cruise at about 115k/hr. (65mph)

Immediately i noticed a flutter from the motor. Reduced speed, motor flutter got worse, dash board message came on saying car had to be serviced. Drove to Porsche garage while motor continued to operate but motor shudder was getting worse.

Porsche tech pulled computor data saying motor had been over reved to 9500 rpm by downshifing. Valve was bent after striking piston head. Porsche servive manager, immediately made it clear that it was my fault and warranty did not cover new motor cost. Service and attitude from Porsche NordenHaus was so insulting I had car removed to another Hi end qualified garage. I had motor pulled apart. Garage tech said oil pump shaft had sheared off and parts scattered throughout motor. Cause, effect and consequences of shaft failure, valve impact and motor over rev seem to be related, but not sure how.

I need to have some feed back from anyone out there that has ideas or knowledge of any occurences similar to this or any othe ideas.

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Posted
Searching for an answer.

Driving a 2006 Boxter, 2.7 , 5 speed with 40K. I am an experienced driver with 40 years of driving manual transmissions hi performance sport cars.

After acceleratiing from a stop sign, first gear to 4000 rpm, shifted to 2nd gear up to 6700 rpm then upshifted to 3rd gear to cruise at about 115k/hr. (65mph)

Immediately i noticed a flutter from the motor. Reduced speed, motor flutter got worse, dash board message came on saying car had to be serviced. Drove to Porsche garage while motor continued to operate but motor shudder was getting worse.

Porsche tech pulled computor data saying motor had been over reved to 9500 rpm by downshifing. Valve was bent after striking piston head. Porsche servive manager, immediately made it clear that it was my fault and warranty did not cover new motor cost. Service and attitude from Porsche NordenHaus was so insulting I had car removed to another Hi end qualified garage. I had motor pulled apart. Garage tech said oil pump shaft had sheared off and parts scattered throughout motor. Cause, effect and consequences of shaft failure, valve impact and motor over rev seem to be related, but not sure how.

I need to have some feed back from anyone out there that has ideas or knowledge of any occurences similar to this or any othe ideas.

No down shift was involved. I went from 2nd to 3rd to bring the revs down. Downshifting from 2nd to 1st would have been difficult to say the least.

Posted

The over rev will be marked by the hours of engine operation in the ECU. Example: If the engine has 100 hours on it and the failure happened at 100 hours and a over rev occurred at 100 hours then it all adds up.

  • Moderators
Posted

There is info for overrevs for the 997. http://www.renntech.org/forums/index.php?s...769&hl=memo I have not seen such info for the 987. I do not know how the 6 ranges for the 997 are different than a 987. I do know the 987 also has 6 ranges because I have seen it on a PIWIS hooked up to a 987. One of these days I will ask one of the mechanics for the 987 info.

The 997 memo says fuel shut off it a 7,300 rpm. I assume the 987 fuel shut off is also about the same. 9,500 rpms would be in range 5 on a 997 and range 5 is 8,401-9,500.

I guess the problem is your dealership can't figure out how you did that unless you missed an downshift. You could not do that upshifting under acceleration because the fuel to engine would have been cut off by the rev limiter before your rpms got high enough to damage the engine.

These rpm figures are transmitted to Porsche in Atlanta. Atlanta has to authorize your dealer to replace an engine under warranty if your dealer wants to get paid. If your dealer just simply ordered a replacement engine and put it in without authorization, then your dealer or you would eat the cost.

I do not know if the rev limiter was working. I do not know how you got into such a high rpm range under acceleration. I do not know if the oil pump shaft failure is related to an rpm issue or just a bad oil pump. I do not know how a piston can hit the valves due to an oil pump failure, as the usual cause for valve impact is a high rpm situation when the piston moves so fast up and down the valves cannot open and close fast enough to keep up with the piston.

Never hear of this happening on a 987, for what little that is worth.

You might get the DME report to see what you have in the 6 ranges. There is a time clock for them. Then you compare the operating hours for the highest range with the total engine operating hours. If they are about the same then that is an additional problem.

Posted
There is info for overrevs for the 997. http://www.renntech.org/forums/index.php?s...769&hl=memo I have not seen such info for the 987. I do not know how the 6 ranges for the 997 are different than a 987. I do know the 987 also has 6 ranges because I have seen it on a PIWIS hooked up to a 987. One of these days I will ask one of the mechanics for the 987 info.

The 997 memo says fuel shut off it a 7,300 rpm. I assume the 987 fuel shut off is also about the same. 9,500 rpms would be in range 5 on a 997 and range 5 is 8,401-9,500.

I guess the problem is your dealership can't figure out how you did that unless you missed an downshift. You could not do that upshifting under acceleration because the fuel to engine would have been cut off by the rev limiter before your rpms got high enough to damage the engine.

These rpm figures are transmitted to Porsche in Atlanta. Atlanta has to authorize your dealer to replace an engine under warranty if your dealer wants to get paid. If your dealer just simply ordered a replacement engine and put it in without authorization, then your dealer or you would eat the cost.

I do not know if the rev limiter was working. I do not know how you go into such a high rpm range under acceleration. I do not know if the oil pump shaft failure is related to an rpm issue or just a bad oil pump. I do not know how a piston can hit the valves due to an oil pump failure, as the usual cause for valve impact is a high rpm situation when the piston moves so fast up and down the valves cannot open and close fast enough to keep up with the piston.

Never hear of this happening, for what little that is worth.

You might get the DME report to see what you have in the 6 ranges. There is a time clock for them. Then you compare the operating hours for the highest range with the total engine operating hours. If they are about the same then that is an additional problem.

Posted
There is info for overrevs for the 997. http://www.renntech.org/forums/index.php?s...769&hl=memo I have not seen such info for the 987. I do not know how the 6 ranges for the 997 are different than a 987. I do know the 987 also has 6 ranges because I have seen it on a PIWIS hooked up to a 987. One of these days I will ask one of the mechanics for the 987 info.

The 997 memo says fuel shut off it a 7,300 rpm. I assume the 987 fuel shut off is also about the same. 9,500 rpms would be in range 5 on a 997 and range 5 is 8,401-9,500.

I guess the problem is your dealership can't figure out how you did that unless you missed an downshift. You could not do that upshifting under acceleration because the fuel to engine would have been cut off by the rev limiter before your rpms got high enough to damage the engine.

These rpm figures are transmitted to Porsche in Atlanta. Atlanta has to authorize your dealer to replace an engine under warranty if your dealer wants to get paid. If your dealer just simply ordered a replacement engine and put it in without authorization, then your dealer or you would eat the cost.

I do not know if the rev limiter was working. I do not know how you go into such a high rpm range under acceleration. I do not know if the oil pump shaft failure is related to an rpm issue or just a bad oil pump. I do not know how a piston can hit the valves due to an oil pump failure, as the usual cause for valve impact is a high rpm situation when the piston moves so fast up and down the valves cannot open and close fast enough to keep up with the piston.

Never hear of this happening, for what little that is worth.

You might get the DME report to see what you have in the 6 ranges. There is a time clock for them. Then you compare the operating hours for the highest range with the total engine operating hours. If they are about the same then that is an additional problem.

Thanks for the information.

I have been given a log of all this range information.

I have not considered asking if the rev limiter was working.

While accelerating in 2nd gear to 6700 rpm I was careful not to go up to the cut off rev of 7000 rpm because the motor will cut out and the car will jerk as it slows down. My speed was about 120 km/hr. ( 65mph) at 6700 rpm so I shifted up to 3rd gear. Shifting into 1st gear would have been difficult.

My confusion is that I know how I shifted and I still have a computor printout that show the car over revved.

Both the garage mechanics and I are confused with this situation. Nothing seems to have caused the events or perhaps they all did.

I will be dropping in a new motor so I can enjoy this fine car on the road this spring.

Just looking for some answers.

Posted

I guess it depends where the rpm is measured. If it is on the flywheel then the over revving would need to be genuine to give this result. If however it is on the camshaft or part of the drive chain assembly then there could easilly be a sudden violent acceleration as the chain lost its tension and slack was taken up. The feedback could see a rapid accelearaion caused by this slack being taken up just as the engine expired, this would be interpreted by the ECU as an RPM increase and possibly lead to your over rev. If you could get the engine speed sensor checked and find its location this may help resolve some of the confusion.

Posted
I guess it depends where the rpm is measured. If it is on the flywheel then the over revving would need to be genuine to give this result. If however it is on the camshaft or part of the drive chain assembly then there could easilly be a sudden violent acceleration as the chain lost its tension and slack was taken up. The feedback could see a rapid accelearaion caused by this slack being taken up just as the engine expired, this would be interpreted by the ECU as an RPM increase and possibly lead to your over rev. If you could get the engine speed sensor checked and find its location this may help resolve some of the confusion.

Thanks

I will look into this

Have a good day.

  • Moderators
Posted

987 fuel cut at 7200 rpm range 1: 7200-7500 range 2: 7500-7700 range 3: 7700-7900 range 4: 7900-8400 > probably engine damage range 5: 8400-9500 > engine damage range 6: 9500-11000 > engine damage Bosch Cartronic ( DME ) 7.8 40 engine speed sensor on crankshaft.

Posted
987 fuel cut at 7200 rpm range 1: 7200-7500 range 2: 7500-7700 range 3: 7700-7900 range 4: 7900-8400 > probably engine damage range 5: 8400-9500 > engine damage range 6: 9500-11000 > engine damage Bosch Cartronic ( DME ) 7.8 40 engine speed sensor on crankshaft.

RFM, these ranges look much different than the ranges posted by Loren a couple months ago, IIRC. I'll check when I get home.

  • Admin
Posted

I posted ranges for a 997:

The 6 ranges are:

Range 1: 7300-7500 RPM

Range 2: 7500-7700 RPM

Range 3: 7700-7900 RPM

Range 4: 7900-8400 RPM

Range 5: 8400-9500 RPM

Range 6: 9500-11000 RPM

You really don't need to worry about anything other than ranges 4 to 6.

So the only one that is different is range 1 (by 100 RPM).

  • Moderators
Posted

Loren is right 997 is different in range 1.

Posted

Hi Tool Pants, I was given a printout and Porsche calls it a "Working Log". On this it shows the #of ignitions in ranges 1 to 6 inclusive as you know. The "Motor Over-speed Ignition Ranges" is a generic printout indicating ranges for all models. The 987 Boxster and 997 Carrera are categorized together and have the identical ranges. They are:

Range 1 >7300 and <7500

Range 2 >7500 and <7700

Range 3 >7700 and <7900

Range 4 >7900 and <8400

Range 5 >8400 and <9500

Range 6 >9500

I have been able to confirm that fuel cut-off occurs in the region around 8400 for the 987. I understand that Porsche does not disclose accurate values to the general public. I have been informed also that there have been instances where ignitions have been in excess of 16000 where cars have been abused when a driver has gone from 6th gear to 1st at high speeds. Higher range ignitions are not recommended nor good for the engine and may lead to Porsche refusing warranty repairs.

Cheers, thought this would help you guys :)

  • Admin
Posted
The 987 Boxster and 997 Carrera are categorized together and have the identical ranges.

Sorry but some of your information is not correct.

Since the 987 and 997 have different redlines how could they have the same starting ranges. They are not the same for all models. What RFM stated above (for the 987) is correct. ANd , what I stated above is correct for 997.

Fuel cutoff can not help you if you miss a downshift and force the motor to run too fast.

The rev limiter protects the motor for normal over revs but can not prevent damage from missed downshifts or other mechanical overruns (like spinning the car and running the engine backwards).

Posted (edited)

I have an actual copy of the generic printout, the service manager gave it to me and I called the service dept about the other info before posting. I have a pretty good relationship w/my dealer here fortunately.

For the 997 GT3 the data is:

9000-9200, 9200-9400, 9400-9600, 9600-10000, 10000-11000, +11000

And for the 997 Turbo the data is:

6800-7000, 7000-7200, 7200-7400, 7400-7900, 7900-9000, +9000

Edited by eqs
  • Moderators
Posted

Saraf, if you want to scan and email me the working log I might get someone to look at it. Black out the VIN.

If you were in 9,500 then you were in at least range 5. What I think is important is when did it happen in relationship to the engine failure. That is why you need to look at the engine operating hours for the 9,500 incident, and compare that number with the number for the total engine operating hours.

This is an example. A local 2000 Boxster S. We went on a drive from San Jose to Santa Cruz, about an hour drive. Upon arrival in Santa Cruz we had out cars hooked up to a PST2.

Engine operating hours is 1,167.2. The car got into range 1 at 1,167.1 hours. So that means the car got into range 1 on the drive. Range 1 however means nothing.

Last range 2 was at 1,111 operating hours. Range 2 can damage the engine. But the last range 2 was 56.2 engine operating hours earlier. So if the engine had failed during the drive it would not be because it had been in range 2 56.2 operating hours earlier.

post-4-1210193121_thumb.jpg

Posted
Saraf, if you want to scan and email me the working log I might get someone to look at it. Black out the VIN.

If you were in 9,500 then you were in at least range 5. What I think is important is when did it happen in relationship to the engine failure. That is why you need to look at the engine operating hours for the 9,500 incident, and compare that number with the number for the total engine operating hours.

This is an example. A local 2000 Boxster S. We went on a drive from San Jose to Santa Cruz, about an hour drive. Upon arrival in Santa Cruz we had out cars hooked up to a PST2.

Engine operating hours is 1,167.2. The car got into range 1 at 1,167.1 hours. So that means the car got into range 1 on the drive. Range 1 however means nothing.

Last range 2 was at 1,111 operating hours. Range 2 can damage the engine. But the last range 2 was 56.2 engine operating hours earlier. So if the engine had failed during the drive it would not be because it had been in range 2 56.2 operating hours earlier.

Thanks.

I will check on the paper printout they gave me and email it to you for your inspection.

The Porsche Dealer ship was very reluctant to give me more than general information. All they would give me is information that would support their position that I had downshifted the car and caused all the damage and they wanted me to pay for it immediately.

They also suggested that if I took it to an outside source for information or repair I would lose all the "Good Will" the dealership was passing on to me. We have only one Porsche dealership in our area "a captive market for them".

Take care

Posted
Saraf, if you want to scan and email me the working log I might get someone to look at it. Black out the VIN.

If you were in 9,500 then you were in at least range 5. What I think is important is when did it happen in relationship to the engine failure. That is why you need to look at the engine operating hours for the 9,500 incident, and compare that number with the number for the total engine operating hours.

This is an example. A local 2000 Boxster S. We went on a drive from San Jose to Santa Cruz, about an hour drive. Upon arrival in Santa Cruz we had out cars hooked up to a PST2.

Engine operating hours is 1,167.2. The car got into range 1 at 1,167.1 hours. So that means the car got into range 1 on the drive. Range 1 however means nothing.

Last range 2 was at 1,111 operating hours. Range 2 can damage the engine. But the last range 2 was 56.2 engine operating hours earlier. So if the engine had failed during the drive it would not be because it had been in range 2 56.2 operating hours earlier.

Hi again

The over rec occured when the motor broke.

I am trying to understand a couple of items.

Does the unit record only the ignition hits as the engine revs to the high end rev - 9500 rpm or does it record as it goes up and then as the revs drop back down?

Range 1 is 7300 to 7500 ppm (as they have stated) had 4244 ignitions. In real time (seconds) how long a time period is this?

Range 2 - 7500 - 7700 rpm had 456 ignitions, in real time (seconds) how long a time period is this?

Range 3 - 7700- 7900 rpm had 1 ignition. Again how long

Range 4 - 7900 - 8400 rpm had 256 ignitions

Range 5 8400- 9500 had 256 ignitions

Range 6 - 9500 - had 1 ignition.

My understanding is 6 ignitions would be the 6 spark plugs firing in 1 rpm.

Next question - How easy or hard is it to downshift from 2nd gear at 4000 rpm to 1st gear? (missing the shift to third and accidentially going into 1st? What would have be the sound in the car and the physical results of this mishift?

If the car was in 2nd gear at 9500 rpm and had been downshifted from 3rd gear, what would the rpm have been in 3rd gear and what would have been the road speed of the car just before shift? Is there a formula for this on a 5 speed manual with regulation tires and wheels?

Again what if the downshift was from 3rd to 2nd?

I have some calculations but would like independent results.

Thanks

Posted (edited)

256 in 4 and 5 and 1 in 6 would have been very high numbers based on what the service manager was telling me in generalities. What I had posted earlier was just the information I had received essentially verbatim from the dealer. That is why I have posted in the past that a DME download is a critical factor to consider when purchasing used vehicles - it can tell you information no one else can tell you about the history of the vehicle you're considering. Lotus I understand also has this sort of "black box".

Next question - How easy or hard is it to downshift from 2nd gear at 4000 rpm to 1st gear? (missing the shift to third and accidentially going into 1st? What would have be the sound in the car and the physical results of this mishift?

If the car was in 2nd gear at 9500 rpm and had been downshifted from 3rd gear, what would the rpm have been in 3rd gear and what would have been the road speed of the car just before shift? Is there a formula for this on a 5 speed manual with regulation tires and wheels?

Again what if the downshift was from 3rd to 2nd?

I'd also check out your tranny too with that type of shifting.

Just my 2c, cheers :)

Edited by eqs
Posted
Holy cow, that's a ton of over-revs! That car has been very abused. Are you the original owner?

Yes.

I purchased the vehicle new from the dealership.

It had 890 (550 miles) km on it when I took it over, but they said it had been to the race track during that time.

They assured me that everything was great with the motor. I cannot believe that this recent occurance was caused by something that happened then.

The master mechanics I have looking at the destruction in the motor are stumped as I am, as to why this all happened.

If I had downshifted I would have a ready explanation for this occurance, but I did not.

Not that it matters, I will replace the motor with my own dollar, but sure would like to have some answers.

I am still trying to know how seconds the motor would take to have 4420 hits at 7300 rpm?

Still mystified? :-)

Posted

4420 hits is the amount of ignition cycles. They all didn't happen at 7300 RPM, only recorded at that RPM. It's hard to put that into a time frame of seconds.... I could be wrong but this is how I understand it all.

Posted

Now wait a minute, you say you bought it "new" but it was tracked in the first 550 miles. This engine was not even properly broken in yet! What were they thinking? Would anyone know if improper break in would play a role in this terrible engine breakdown? I think the owner's manual says to break in, without exceeding 4200 RPM, for the first 2000 miles.

Posted

SPIRO, I think that whoever was using it was abusing it, that's why Porsche denied the replacement. I've made these comments to others, that you can't expect any manufacturer to repair or replace components if they have been abused by you or anyone else. People may say they will, but I believe they will be in for an uphill battle in court.

And if the dealer did in fact track/abuse this car, you should contact the dealer and inform them of your plight, and get them to take responsibility and pay for it.

Anyways just my 2c.

Cheers :)

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