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Re: pissed off. Check engine light over-revs....
Quote:
rhino said:
I wonder if my dealer can check my PTS2 before I take delivery just to make sure nobody has redlined my brand new car??? He will probably laugh
The car is delivered to the dealer in a restricted 'production' mode, which limits the vehicle to a top speed of @20 mph.... so no you don't have anything to worry about....It's a shame you need the piwis computer to access the mode, because it would make a great valet mode....hell, it should have been a toggle box on the pcm
Re: pissed off. Check engine light over-revs....
Quote:
RC said:
...
BTW: a little hint for those who have the Sport Chrono installed. As far as I understand, the sport chrono package, when activated, has a faster and more "brutal" rev figure cut-off, just in case of over-revving the engine or even mishifts. I'm not sure if this 100% accurate but I remember somebody telling me that.
That is true RC. Bill? Buckley?, the Cayman dealer trainer for PCNA, at a recent PCA event, stated exactly that. With the sport chrono package is active, you are allowed to rev all the way to the limit before the engine cutoff. With it off or without sport chrono, you are not allowed to hit the limit without intervention way before.
Re: pissed off. Check engine light over-revs....
Is it possible that the PSE can also cause over-revs? According to the same PCNA rep, if you downshift and the rear tires are going to lock up, the PSE will increase the engine speed to get traction on the rear wheels. Even if this is only for a split second, could an over-limit occur?
Apr 21, 2006 11:43:36 AM
- wpozzz99zs
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Re: pissed off. Check engine light over-revs....
Quote:
vtrader said:
Is it possible that the PSE can also cause over-revs? According to the same PCNA rep, if you downshift and the rear tires are going to lock up, the PSE will increase the engine speed to get traction on the rear wheels. Even if this is only for a split second, could an over-limit occur?
Is it possible that the PSM can also cause over-revs? According to the same PCNA rep, if you downshift and the rear tires are going to lock up, the PSM will increase the engine speed to get traction on the rear wheels. Even if this is only for a split second, could an over-limit occur?
Sorry, posted the original late last night should be PSM and not PSE.
Re: pissed off. Check engine light over-revs....
Vtrader:
I'm thinking that PSM won't force an increase in engine speed if that increase would take you past the hard limiter.
OTHO, a missed gear on a downshift could easily take you into valve bending range, and I think that that's the issue here...
I dunno for sure, I didn't write the code for PSM. I'm assuming that the rules are Life Safety first, and vehicle health second - but I can't imagine PSM commanding a hard over-rev.
Damn, this sucks. My car only had 14 miles on it at delivery, but this thread makes me want to look at the stats anyway.
-d
I'm thinking that PSM won't force an increase in engine speed if that increase would take you past the hard limiter.
OTHO, a missed gear on a downshift could easily take you into valve bending range, and I think that that's the issue here...
I dunno for sure, I didn't write the code for PSM. I'm assuming that the rules are Life Safety first, and vehicle health second - but I can't imagine PSM commanding a hard over-rev.
Damn, this sucks. My car only had 14 miles on it at delivery, but this thread makes me want to look at the stats anyway.
-d
Re: pissed off. Check engine light over-revs....
Porschesky--don't believe for a minute that a few missed downshifts will trash this engine. They are pretty tough. But,--make sure that THEY (the dealership) recognize that the issue is that this was a pre-existing condition. With all the data points that these black boxes can track they can plot all this out and SEE quite vividly that you are a conservative driver and any issues with the engine can't be attributed to your style of driving. Stand firm on this.
Thanks to you for sharing this information, which may ultimately save the rest of us from similar issues.
Dan
Thanks to you for sharing this information, which may ultimately save the rest of us from similar issues.
Dan
Re: pissed off. Check engine light over-revs....
Quote:
vtrader said:
Is it possible that the PSM can also cause over-revs? According to the same PCNA rep, if you downshift and the rear tires are going to lock up, the PSM will increase the engine speed to get traction on the rear wheels. Even if this is only for a split second, could an over-limit occur?
The PSM function you are thinking of would only rev the engine sufficiently to better match engine speed to actual road speed, to prevent the car from becoming unstable.
Apart from the fact that the ECU would not "order" E-gas to rev the engine beyond red line anyway, this condition could only arise if the driver had shifted to too low a gear for the road speed in the first place.
Apr 22, 2006 10:03:15 PM
- Trundle_GT3
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Re: pissed off. Check engine light over-revs....
PIWIS system tester now breaks down Type 2 over revs for the 997 DME 7.8 40 in the following manner:
Number of ignitions, range 1-RPM Range 7,300-7,500
Number of ignitions, range 2-RPM Range 7,500-7,700
Number of ignitions, range 3-RPM Range 7,700-7,900
Number of ignitions, range 4-RPM Range 7,900-8,400 (Some damage)
Number of ignitions, range 5-RPM Range 8,400-9,500 (Damage)
Number of ignitions, range 6-RPM Range 9,500-11,000 (Damage)
Number of ignitions, range 1-RPM Range 7,300-7,500
Number of ignitions, range 2-RPM Range 7,500-7,700
Number of ignitions, range 3-RPM Range 7,700-7,900
Number of ignitions, range 4-RPM Range 7,900-8,400 (Some damage)
Number of ignitions, range 5-RPM Range 8,400-9,500 (Damage)
Number of ignitions, range 6-RPM Range 9,500-11,000 (Damage)
Re: pissed off. Check engine light over-revs....
Quote:
Damian said:Quote:
Trundle997S said:
First I've heard about subcategories
You either bump the Rev-limiter (type 1)
Or have a mechanical over-run (type2)
Next time I'm hooked up to the PIWIS tester I'll take a pic.
Here is what the PST2 would see:
Trundle997S- thanks for the insight....don't mean to put you on the spot but would the sample 34000 number of ignitions in pic above directly translate to:
34000 ignitions/ 7400 rpm/ 6 cylinders = .77 minutes (45 seconds total) of rev-limiter bump?
FWIW, you have to double the total "overrev" time you calculated above, because only 3 cylinders fire on each rev on a 6-cylinder 4-cycle engine.
PS: I like the "VIN covered to protect the guilty".
Re: pissed off. Check engine light over-revs....
Quote:
dstrimbu said:
OTHO, a missed gear on a downshift could easily take you into valve bending range, and I think that that's the issue here...
Sorry guys, I mis-spoke... I didn't mean a missed gear (as in neutral), I meant the wrong gear (as in Fritz's comment about "...too low of a gear for the road speed").
Revving high in third and shifting into second instead of fourth - that's the type of action I was referring to...
Regardless - keep us posted as to what you find!
-d
Re: pissed off. Check engine light over-revs....
damn thats a bad problem... like i posted another day... my CS had problems with the clutch i think.. things without explication... but about the over-rev.. a time ago, i was driving in 5th, i was so excited with the speed that i forgot to change the gear.. 253 km/h and a listen a strange noise... 
over-rev! so i change the gear to 6th and go again!
over-rev! so i change the gear to 6th and go again!
Re: pissed off. Check engine light over-revs....
This is a bit confusing, is it the case that if you rev your car to the red parts of the revometer that it will definitely do engine damage? What happens if this has only happened once or twice(in first gear? I thought these cars were meant for tough driving!!
Apr 24, 2006 10:55:39 AM
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Jay
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Re: pissed off. Check engine light over-revs....
I had one over-rev on my car. Nothing major. I asked the dealer when it happened (at what milage), he couldn't tell me that but did tell me at what operating hour it occured and my total hours. Then I worked it out to be ~= the time I was on the track.
Ask for the missing data. Then you will know (most likely) if you owned the car then.
Ask for the missing data. Then you will know (most likely) if you owned the car then.
Apr 24, 2006 5:44:39 PM
- porschesky
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Re: pissed off. Check engine light over-revs....
Talked the the dealership again. They asked me what I wanted to do and I told them I want the car re-certified. The dealer said no, but then said it would check to see if possible. I explained that if it wasn't possible then they are going to be getting the car back. Immediately, they are now telling me I can trade the car into them for another car. My guess is that they will try to make more money off of me. I would have thought that when a flagship Porsche dealership takes a car in, they would run it through this computer thing to see if the engine has been abused. My guess is that re-building an engine is not considered part of the re-conditioning process of a used car. If it were my dealership, I would plug any possible trade in into the computer to see what its status is prior to taking the car in. At least it could be used for record purposes. My biggest complaint here is that if I had not know better, and had I not been a member of this board, I would have assumed that it was me that did the over-revs and ultimately it would have been me that paid for damage as we all know the dealer would never step forward with this information except for an educated consumer like me. If this dealership does not resolve the problem, I will sue them. At least maybe they won't try and screw the next Porsche buyer that comes along. I'll keep you all posted. Once again thanks to the board members for all of your help
Apr 24, 2006 7:47:03 PM
- edz
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Re: pissed off. Check engine light over-revs....
Quote:
porschesky said:
Talked the the dealership again. They asked me what I wanted to do and I told them I want the car re-certified. The dealer said no, but then said it would check to see if possible. I explained that if it wasn't possible then they are going to be getting the car back. Immediately, they are now telling me I can trade the car into them for another car. My guess is that they will try to make more money off of me. I would have thought that when a flagship Porsche dealership takes a car in, they would run it through this computer thing to see if the engine has been abused. My guess is that re-building an engine is not considered part of the re-conditioning process of a used car. If it were my dealership, I would plug any possible trade in into the computer to see what its status is prior to taking the car in. At least it could be used for record purposes. My biggest complaint here is that if I had not know better, and had I not been a member of this board, I would have assumed that it was me that did the over-revs and ultimately it would have been me that paid for damage as we all know the dealer would never step forward with this information except for an educated consumer like me. If this dealership does not resolve the problem, I will sue them. At least maybe they won't try and screw the next Porsche buyer that comes along. I'll keep you all posted. Once again thanks to the board members for all of your help
It all makes sense now. These guys will sell you a new car, making profit of course and then depreciate your car which translates in you taking a loss as expected. Finally they will fix your car and sell it as a Porsche used certified vehicle and make a good profit on that car too
.
Re: pissed off. Check engine light over-revs....
Quote:
zster786 said:
This is a bit confusing, is it the case that if you rev your car to the red parts of the revometer that it will definitely do engine damage? What happens if this has only happened once or twice(in first gear? I thought these cars were meant for tough driving!!
They're tough, Zster - but a mechanical over-rev isn't going to happen by bumping the rev limiter under acceleration. That's why it's there - it'll work hard to cut fuel before the revs run away... the issue is, as stated before "...selecting too low of a gear for the road speed". For example, going from third gear at high revs to second instead of fourth.
A forced downshift that locks the rear wheels will likely cause damage, bacuse the rev limiter can't stop the engine from overspeeding at that point... the inertia of the car plus the gear multiplication will run the engine past its safe limits.
Fine as this engine is, it has physical limits. Physically forcing the engine speed past its hard limits will cause metal-to-metal contact - piston to valve, for example - and that's going to break stuff.
The flat 6 is an interference engine - the valves intrude past the piston position at certain points in the operating cycle. As long as the timing chains are intact and the RPMs stay below the operating max (about 7,900 as seen in a post above), there will be no contact.
Once you exceed that hard limit, parts that aren't supposed to touch might do so... and that's the issue.
Hitting the soft limiter in first won't hurt anything, but grabbing second gear at 80 mph will make a BIG mess.
-d
Apr 25, 2006 4:34:28 PM
- Dilinger
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Re: pissed off. Check engine light over-revs....
porschesky, i m sorry for you adventure,at least you are in the correct way...
1) I think the car was over revved during its previous ownership
2)Your dealer should have checked the history in the computer diagnostic tool before selling....
a) They checked and played the fools
b) They thought that a brand new car would have a clear driving history so they skipped the check..
Make sure you get the best out of this... and try to concentrate on the fact that they SHOULD of checked the history before selling you the car...That can cause them damage...
BUT take a copy of the over revving dates..
NOW concerning sport chrono..
RC, is correct about the fact that sport chrono, involves a "harder" and brutal rev limiter to protect the engine under hard driving conditions...
Due to the fact that, sports chrono acts as a "second mapping" of the engine, it helps the engine rev up during higher rev range..and to protect it at the limit it SETS the rev limiter a LITTLE lower than normal..so that the engine is well protected...
OF course, i seriously doubt, that it protects the engine from down-shifting.That something ,no rev-limiter, i have heard can do.
NOW concerning the straight rev-up during upshifting .
IT CANNOT HURT TYHE ENGINE IF YOU ACCELERATE STRAIGHT TO THE LIMITER
with or without sport chrono on...
1) I think the car was over revved during its previous ownership
2)Your dealer should have checked the history in the computer diagnostic tool before selling....
a) They checked and played the fools
b) They thought that a brand new car would have a clear driving history so they skipped the check..
Make sure you get the best out of this... and try to concentrate on the fact that they SHOULD of checked the history before selling you the car...That can cause them damage...
BUT take a copy of the over revving dates..
NOW concerning sport chrono..
RC, is correct about the fact that sport chrono, involves a "harder" and brutal rev limiter to protect the engine under hard driving conditions...
Due to the fact that, sports chrono acts as a "second mapping" of the engine, it helps the engine rev up during higher rev range..and to protect it at the limit it SETS the rev limiter a LITTLE lower than normal..so that the engine is well protected...
OF course, i seriously doubt, that it protects the engine from down-shifting.That something ,no rev-limiter, i have heard can do.
NOW concerning the straight rev-up during upshifting .
IT CANNOT HURT TYHE ENGINE IF YOU ACCELERATE STRAIGHT TO THE LIMITER
with or without sport chrono on...
Re: pissed off. Check engine light over-revs....
Quote:
vtrader said:Quote:
RC said:
...
With the sport chrono package is active, you are allowed to rev all the way to the limit before the engine cutoff. With it off or without sport chrono, you are not allowed to hit the limit without intervention way before.
that is not true, YOU can hit the rev limiter all the way without damaging the engine, even if you dont step out of the gas immediately..
Even a daihatsu can do that!
Re: pissed off. Check engine light over-revs....
Quote:
zster786 said:
Thanks dstrimbu! That makes perfect sense - I was a bit worried before but there are new things I am learning about this amazing car everyday!
Anytime, Zster... I am also exploring this beautiful machine every time I get in or near it.
So... I didn't plan this, but I did hit the hard limiter last night - in second gear. I've been very "good" regarding engine speeds (not quite as anal retentive as the US manual suggests, but still generally clear of redline - and then only when the oil temp was above 200 degrees F).
I took off normally from a traffic light - Sport Mode ON, PASM Normal, PSM ON. Of course, the guy next to me floored his car - so I did, also.
Into second gear at 7,000 - and before I knew it, I was at 67mph and the hard limiter - 7,400 RPM - in second gear. Holy smokes, does this car pull hard or what!?!
Important to note that the tach never went over 7,600 indicated. The fuel cutoff is _hard_ in Sport Chrono mode. At that point, I was so amazed that I backed off the gas, plopped it into fourth and coasted down to 55mph...
The system works. I'll be interested to see what PIWIS says next time I'm in to the dealer.
Be safe, have fun! No street racing! <g>
-don
Apr 25, 2006 5:58:55 PM
- dstrimbu
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Apr 26, 2006 1:17:52 AM
- porschesky
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Re: pissed off. Check engine light over-revs....
***UPDATE****
The Porsche dealership is agreeing to re-certify the car and tag on an additional 3 years of warranty to the car. I would bet after this, they make it part of their process to check the engine computer diagnostics from now on.
The Porsche dealership is agreeing to re-certify the car and tag on an additional 3 years of warranty to the car. I would bet after this, they make it part of their process to check the engine computer diagnostics from now on.
Re: pissed off. Check engine light over-revs....
Quote:
Dilinger said:Quote:
vtrader said:Quote:
RC said:
...
With the sport chrono package is active, you are allowed to rev all the way to the limit before the engine cutoff. With it off or without sport chrono, you are not allowed to hit the limit without intervention way before.
that is not true, YOU can hit the rev limiter all the way without damaging the engine, even if you dont step out of the gas immediately..
Even a daihatsu can do that!
Dilinger, you mis-read the post. No one is saying that you will damage the engine if you hit the rev limiter. The post only stated that the rev limiter works differently when the sport chrono mode is active or not. Thats all.
When you have the sports chrono mode on, you can go all the way to redline and then the engine will cutoff instantly. With the sports chrono mode off or no sports chrono, the engine will start to moan and groan before the redline.
The rpm limiter characteristic is "harder", i.e.
the engine is immediately throttled when the
performance limits are reached...
Dilinger, what are you basing your statement on? By the way, the italics came from the 997 manual.
Re: pissed off. Check engine light over-revs....
Quote:
vtrader said:Quote:
Dilinger said:Quote:
vtrader said:Quote:
RC said:
...
The rpm limiter characteristic is "harder", i.e.
the engine is immediately throttled when the
performance limits are reached...
Dilinger, what are you basing your statement on? By the way, the italics came from the 997 manual.
VTRADER which statement you mean??
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