Has anybody experienced either of these 2 faults?

[Guest]

I have had 2 intermittent faults, neither of which appear to have affected the car's performance: the battery/generator fault light comes on, sporadically, usually under acceleration. The first time it occured was when i hit the rev limiter. It occured once more, shortly afterwards, under acceleration and then didn't happen again for another month or so, again when i hit the rev limiter. This time, subsequently the fault light came back on more often. The 2nd fault has been a knocking noise, which feels like its coming from under the car, somewhere in front of my right foot. There doesn't appear to be any consistency, except that it has never occured under breaking or going over bumps, but does tend to happen a split second after changing gear, at low speeds, but also a couple of times when just going along and a couple of times when cornering (again at very low speed). The only thing that i can think of that's different is i put super unleaded in a few weeks ago, having previously used regular most of the time. Last week i booked the car in to have it looked at, and needless to say, since then, both faults have gone away.
The car is at Lancasters today, and they have investigated the battery light and can find no drop in voltage, but concluded that it is a software problem, and have asked Porsche was assistance (!). They have been unable to replicate the knocking noise. Has anyone had either of these faults and got any clues ??

Many thanks

Nick

 

[davecunningham]

how old is your car?

 

[Guest]

hi, it's May 2005

 

[Geoff_Fields]

No experience of those faults for me. But why are you not using 98 super unleaded fuel all the time? What's the point in buying a performance car only to strangle it with low octane fuel. On another point, I would suggest you use the rev counter rather than banging into the limiter. Abuse of revs are logged for the OPC to see.

 

[Guest]

i've hit the rev limiter twice since i bought the car. Is that a crime ?

 

[Geoff_Fields]

No, I misread the intonation of your first post.

 

[sidicks]

ORIGINAL: Geoff997

No experience of those faults for me. But why are you not using 98 super unleaded fuel all the time? What's the point in buying a performance car only to strangle it with low octane fuel. On another point, I would suggest you use the rev counter rather than banging into the limiter. Abuse of revs are logged for the OPC to see.

1) The 'S' revs so smoothly, it's quite easily to accidentally bump the limiter.....

2) Only Superunleaded (Optimax) for my baby - I used the same for my BMW M3 and for my Audi S3 previously. As well as improve performance, it is meant to contain key additives to clean the engine and improve responsiveness. I'm sure Porsche recommend Super unleaded for a reason....!!

Sidicks

 

[Guest]

ORIGINAL: Geoff997

No, I misread the intonation of your first post.

I suggest you read the posts a little more carefully in that case. If you have something constructive to say, that would be appreciated. But you can save the insults for the playground.

Lancasters have solved the knocking issue. Apparently a loose "flex" (whatever that is).

 

[Guest]

ORIGINAL: sidicks

1) The 'S' revs so smoothly, it's quite easily to accidentally bump the limiter.....

2) Only Superunleaded (Optimax) for my baby - I used the same for my BMW M3 and for my Audi S3 previously. As well as improve performance, it is meant to contain key additives to clean the engine and improve responsiveness. I'm sure Porsche recommend Super unleaded for a reason....!!

Sidicks

I'm sure you're right about super. Laziness on my part. Tho i can't tell the difference in terms of perfomance, on the road or track. But longevity etc is another matter i guess....

 

[sidicks]

ORIGINAL: bluffield
I'm sure you're right about super. Laziness on my part. Tho i can't tell the difference in terms of perfomance, on the road or track. But longevity etc is another matter i guess....

I think under performance testing you'd probably see some small benefits using Superunleaded, but on the road the benefits are pretty small. Many people say that the fuel consumption is better with Superunleaded, so that compensates for the greater initial cost. And as I've said, the long-term benefits of using Optimax are also worth having, assuming you're keeping the car for a reasonable length of time!!

In terms of laziness, the optimax pump is right next to the ordinary unleaded pump, so there isn't much extra effort required !! (unless you've got trouble in finding a Shell garage nearby, but that just gives you an excuse to drive it further....)

In summary, don't pay £70k for a car and skimp 5p a litre on fuel !!

Sidicks

 

[pvernham]

I 'bumped' the limiter for the first time last week after 14 months and 12,500 miles. The hard limiter was a surprise, particularly as my car sees the far side of 7,000 revs regularly on most journeys.

But even if there is data logging that the OPC can access, what can they do about it? Surely the whole point of the rev limiter is to protect the engine.

And if 'abuse of revs' were an issue, then surely tracking the car would be just one potential problem that Porsche should advise against.

Sorry, but just sounds a red herring to me.

 

[Guest]

I think under performance testing you'd probably see some small benefits using Superunleaded, but on the road the benefits are pretty small. Many people say that the fuel consumption is better with Superunleaded, so that compensates for the greater initial cost. And as I've said, the long-term benefits of using Optimax are also worth having, assuming you're keeping the car for a reasonable length of time!!

In terms of laziness, the optimax pump is right next to the ordinary unleaded pump, so there isn't much extra effort required !! (unless you've got trouble in finding a Shell garage nearby, but that just gives you an excuse to drive it further....)

In summary, don't pay £70k for a car and skimp 5p a litre on fuel !!

Sidicks
[/quote]


Of course you are quite right about the relative price. I change my car every year or so, and the dep'n is probably 10k pa, which is almost 20k pre-tax, which means i have to work a week to cover it. I should imagine that for me the annual difference in cost between the two fuels is about what i pay for a decent bottle of wine, which i can drink in about an hour! I frankly just dont pay any attention.

 

[Michael Downing]

ORIGINAL: pvernham
But even if there is data logging that the OPC can access, what can they do about it? Surely the whole point of the rev limiter is to protect the engine.

I understood that the logging distinguished between accelerating in gear and hitting the limiter (on the one hand), and changing down when too fast and forcing the engine beyond the rev limit (on the other hand).

The former does not cause the engine to over-rev because the limiter protects it, whereas in the latter case there is nothing the limiter can do to prevent it.

 

[38F3E1]

Which are logged as Type 1 and Type 2 overrev. Type 1 when you hit the limiter is not considered an issue and will have no effect on any warranty work as the engine is still operating within its design range. Type 2 when you put the car in say 3rd instead of 5th or change down too early and overrev the engine beyond its design range does have warranty implications.

Ian.

 

[Guest]

ORIGINAL: ian_uk

Which are logged as Type 1 and Type 2 overrev. Type 1 when you hit the limiter is not considered an issue and will have no effect on any warranty work as the engine is still operating within its design range. Type 2 when you put the car in say 3rd instead of 5th or change down too early and overrev the engine beyond its design range does have warranty implications.

Ian.

I just find that when changing up from 2nd to 3rd, the red line arrives unbelievably quickly. The engine doesn't feel or sound like it's in any way stretched. That's one of the reasons it's so much fun to drive.

 

[Lancerlot]

ORIGINAL: sidicks

ORIGINAL: bluffield
I'm sure you're right about super. Laziness on my part. Tho i can't tell the difference in terms of perfomance, on the road or track. But longevity etc is another matter i guess....

I think under performance testing you'd probably see some small benefits using Superunleaded, but on the road the benefits are pretty small. Many people say that the fuel consumption is better with Superunleaded, so that compensates for the greater initial cost. And as I've said, the long-term benefits of using Optimax are also worth having, assuming you're keeping the car for a reasonable length of time!!

In terms of laziness, the optimax pump is right next to the ordinary unleaded pump, so there isn't much extra effort required !! (unless you've got trouble in finding a Shell garage nearby, but that just gives you an excuse to drive it further....)

In summary, don't pay £70k for a car and skimp 5p a litre on fuel !!

Sidicks

The main reason for using high octane fuel is to avoid detonation since this will quickly destroy an engine. Porsche ECU's take data from an anti-knock sensor and then automatically retard ignition timing if detonation is detected. With this mind no damage will ensue by using a lower octane fuel. However, engine performance will be compromised since retarded ignition equals less power.
As regards available fuel, there seems to be little difference between Shell Optimax (98 octane) and BP Super Unleaded (97 Octane). However selected Tescos outlets are now selling 101 Octane so it may be worth hunting this down if you have a participating outlet near you.
Hope this helps.

 

[Mark_Bennett]

ORIGINAL: Lancerlot
... However selected Tescos outlets are now selling 101 Octane so it may be worth hunting this down if you have a participating outlet near you.
Hope this helps.

Do you mean "Total" rather than Tesco? Or have Tesco started to do it too?

 

[Lancerlot]

ORIGINAL: Mark Bennett

ORIGINAL: Lancerlot
... However selected Tescos outlets are now selling 101 Octane so it may be worth hunting this down if you have a participating outlet near you.
Hope this helps.

Do you mean "Total" rather than Tesco? Or have Tesco started to do it too?

No. I meant Tesco, honest! See http://www.greenergy.com/products/99_octane_locations.html for details. (Seems it's now down to 99 octane though!)

 

[Guest]

ORIGINAL: Lancerlot



The main reason for using high octane fuel is to avoid detonation since this will quickly destroy an engine. Porsche ECU's take data from an anti-knock sensor and then automatically retard ignition timing if detonation is detected. With this mind no damage will ensue by using a lower octane fuel. However, engine performance will be compromised since retarded ignition equals less power.
As regards available fuel, there seems to be little difference between Shell Optimax (98 octane) and BP Super Unleaded (97 Octane). However selected Tescos outlets are now selling 101 Octane so it may be worth hunting this down if you have a participating outlet near you.
Hope this helps.

Interesting. There's a Tesco next to the trian station where i commute from. I'll check it out.

Many thanks

Nick

 

[Mike Pink]

ORIGINAL: bluffield

ORIGINAL: Lancerlot



The main reason for using high octane fuel is to avoid detonation since this will quickly destroy an engine. Porsche ECU's take data from an anti-knock sensor and then automatically retard ignition timing if detonation is detected. With this mind no damage will ensue by using a lower octane fuel. However, engine performance will be compromised since retarded ignition equals less power.
As regards available fuel, there seems to be little difference between Shell Optimax (98 octane) and BP Super Unleaded (97 Octane). However selected Tescos outlets are now selling 101 Octane so it may be worth hunting this down if you have a participating outlet near you.
Hope this helps.

Interesting. There's a Tesco next to the trian station where i commute from. I'll check it out.

Many thanks

Nick

Nick

The local Tesco does have the 99 fuel (on the middle isle []).

I've never used it, but am curious. Does anyone know if Tescos use the same quality/quantity of detergents and other additives as Shell and BP claim to use in their fuels - I wouldn't want to improve short term performance at the expense of longevity?

[PS are you coming to the Intermarque Gathering at Pulloxhill on 23 July - family welcome too? [][]]