Broken oil pump shaft/ motor over rev

[stef]

So the question about how an engine could be protected from overrev on downshift comes up occasionally. It got me to thinking how it might be done.

But with a manual there is no computer control. Any shift that the driver physically makes is acted upon AS SOON AS THE CLUTCH PEDAL IS RELEASED. So why not have the computer not allow that release if it calculates resulting RPM would be too high? The clutch is hydraulic. Some simple computer controlled valving could probably be engineered to override the clutch release by the driver.

Do I think that any manufacturer will ever do this? No. The direction is towards PDK type trannies. There is no upside for the manufacturer to make an overrev-proof manual transmission motor. But it still is an interesting thought.

Regards,

Alan

The real question isn't if it's possible, but the dangers involved in doing that.

Example: I push in the clutch in 5th gear at 90 mph, intending to downshift to 4th but hit 2nd instead. That would make the revs 9000 rpm... so what does the car do? Hold in the clutch? Or does it prevent me from shifting into 2nd?

If it holds in the clutch, I'm coasting which is bad in itself. But what happens when I slow down to 70 (being under the redline in 2nd) ... does it suddenly release the clutch? Ouch!

If it prevents downshifting into 2nd, people will simply become dependent on it as a safety... but like the dangers of relying on the safety on a gun to prevent firing, you're depending on a safety mechanism for your life instead of using proper driving to put it into the correct gear. It also prevents downshifting as you're slowing down without releasing the clutch before the right time, such as approaching a turn really fast while braking.

I wonder if they can come up with a good way to prevent it. A simple alarm might even work with some feedback in the shift lever. Imagine if when I downshifted the lever started vibrating the moment it began moving into 2nd, and the dashboard alarm beeped. I could still jam it and drop the clutch causing a level 4 overrev, but more likely I'd notice something was wrong really fast and not dump the clutch.

Edited July 28, 2008 by stef

[saraf]

Merry Christmas

Just an update to situation.

Porsche Corp and local dealership were deaf, dumb and blind with no response until I filled a claim with the courts on this matter through a lawyer.

Received a very strange reply from them.

Waiting for further movement or comment from them.

Car is still running superbly in this Canadian winter.

Take care.

[saraf]

Just an update. Dispute is now moving toward the courts with company Lawyers using all legal methods to delay the meeting in a court room. First date has been postponed since the said the did not have enough information.

Happy cruising.

[Markieg]

Just an update. Dispute is now moving toward the courts with company Lawyers using all legal methods to delay the meeting in a court room. First date has been postponed since the said the did not have enough information.

Happy cruising.

Newbie here - just read the full thread and curious as to the outcome - any more news?

[Jake Raby]

This is becoming a more common problem.. It recently took one of my engines out of service and accounted for our first failure.

The answer is a billet chromoly replacement part thats total overkill.

[txhokie4life]

This is becoming a more common problem.. It recently took one of my engines out of service and accounted for our first failure.

The answer is a billet chromoly replacement part thats total overkill.

Am I looking at the hex pin from the IMS to the oil pump?

thanks,

Mike

[cnavarro]

Yup!

[saraf]

An update to this issue. I had the motor replaced by a qualified, competent and professional garage and the Porsche runs sweet.

They dumped the information from the computer and they found the information that it contained.

Contrary to the statement that the Porsche dealership made that it could not find the time date stamp when the motor over revved and it must have been the moment before the motor broke; this new information dump said something totally different.

The car has 891.4 operating hours on it when the motor damage occured. The revs at range 1, 7300-7500 rpm and range 2, 7500-7700 rpm, happened before and up to operating hour 828. The four ignition hits in range 3 to 6 happened up to or on operating hour 164, 727 operating hours before the motor broke. The mechanic will attest that 4 ignition hits is not enough to make a motor break.

I have a feeling that the Porsche dealership had the time date information but would not share this with me so they get me to pay for the motor and then claim warranty costs from Porsche.

I am a happy camper since this is hard evidence that Porsche will have to address.

Happy, top down motoring in the city today.

I'm curious to know how this turns out...kindly update as the situation develops. good luck...

Just an update.

Happily I have my ride back on the highway and running perfect.

I have collected the hard data on paper with the requisites written statements backing up the data from qualified personnel and am proceeding in discussion with a lawyer to move forward in small claims court.

Dealership responded to the Better Business Bureau investigation by saying that I got angry for no reason and removed the car before the had a chance to fully investigate the situation.

Justice moves slowly but I am confident the "black box" data proves them incorrect.

Take care

Relaxed motoring

good evening to all

this is an update to the problem that occured as per the above information.

The Porsche dealership and Porsche North America took over 2 1/2 years dragging out this situation before we reached a settlement in my favor.

Happy motoring

Take care

[txhokie4life]

An update to this issue. I had the motor replaced by a qualified, competent and professional garage and the Porsche runs sweet.

They dumped the information from the computer and they found the information that it contained.

Contrary to the statement that the Porsche dealership made that it could not find the time date stamp when the motor over revved and it must have been the moment before the motor broke; this new information dump said something totally different.

The car has 891.4 operating hours on it when the motor damage occured. The revs at range 1, 7300-7500 rpm and range 2, 7500-7700 rpm, happened before and up to operating hour 828. The four ignition hits in range 3 to 6 happened up to or on operating hour 164, 727 operating hours before the motor broke. The mechanic will attest that 4 ignition hits is not enough to make a motor break.

I have a feeling that the Porsche dealership had the time date information but would not share this with me so they get me to pay for the motor and then claim warranty costs from Porsche.

I am a happy camper since this is hard evidence that Porsche will have to address.

Happy, top down motoring in the city today.

I'm curious to know how this turns out...kindly update as the situation develops. good luck...

Just an update.

Happily I have my ride back on the highway and running perfect.

I have collected the hard data on paper with the requisites written statements backing up the data from qualified personnel and am proceeding in discussion with a lawyer to move forward in small claims court.

Dealership responded to the Better Business Bureau investigation by saying that I got angry for no reason and removed the car before the had a chance to fully investigate the situation.

Justice moves slowly but I am confident the "black box" data proves them incorrect.

Take care

Relaxed motoring

good evening to all

this is an update to the problem that occured as per the above information.

The Porsche dealership and Porsche North America took over 2 1/2 years dragging out this situation before we reached a settlement in my favor.

Happy motoring

Take care

Happy to hear it worked out for you -- sorry it took so long.

m

[phillipj]

good evening to all

this is an update to the problem that occured as per the above information.

The Porsche dealership and Porsche North America took over 2 1/2 years dragging out this situation before we reached a settlement in my favor.

Happy motoring

Take care

Excellent!!!!!! :clapping: :clapping: :clapping:

[SPIRO]

Thanks for the follow up. 2 1/2 years -- I was wondering what was taking so long.

[1schoir]

good evening to all

this is an update to the problem that occured as per the above information.

The Porsche dealership and Porsche North America took over 2 1/2 years dragging out this situation before we reached a settlement in my favor.

Happy motoring

Take care

Saraf:

Nothing pays off like persistence!

Kudos to you for persevering. It is difficult, but not impossible, to have Porsche say "Uncle!"

Your Permagrin must be just a bit bigger now! :clapping:

Regards, Maurice.