Cayman S stage 6 over rev!

[paterson12]

Hello, ive been viewing posts on the forum for a while but this is my first time starting a new thread

Ive recently bought a Cayman S which has only had one previous owner from 2006. The car was owned by a lady in her 60s so I expected the best from this car.

To my horror I've just had a read out stating that the car has had 3 ignition timings at the over rev limit of stage 6!!! How did the engine not explode?! The car had been 'operational' for 920 hours, the stage 6 over rev occurred 200 hours ago which could be a few years ago as it's a low mileage vehicle.

As as this occurred 200 hours ago, what should I do? Im assuming bore scoping? Forget about It? Etc?

Im concerned about this so would appreciate some advice. Thanks .

 

[Boomer_Zoomer]

The rev limiter kicks in on the 987 CS at 7600 if I recall correctly. It's function is to protect the car from over-rev self-destruct damage and cuts the fuel supply and ignition.

The only way the over rev range 6 could be spiked is if a lower gear has been selected at high speed. Eg mis-selecting 2nd instead of 4th at 80 mph plus.

If I were you, provided the car is running well with no ominous mechanical engine sounds heard, normal oil consumption, and no smoking exhaust when running, I'd forget about it and enjoy your car. It has run for 200 hours since the over-rev so obviously it is still in one piece!

Brian

 

[paterson12]

I suspect you're right Brian .

The car has just had a health check at Porsche with no issues. Car drives great, no smoke, noises etc.

The service advisor seemed to think this was a big deal, hence my startling concern.

 

[Motorhead]

Joe,

I'd have to agree with Brian.

3 over-revs does sound completely spurious but do you have any information on accompanying over-revs in ranges 1 through 4 at the same time?

Jeff

 

[paterson12]

Jeff, my paper work says:

Range 1: 759

Range 2: 26

Range 3: 16

Range 4: 7

Range 5: 7

Range 6: 3

From what I understood, all occurred 200 hrs ago.

 

[Boomer_Zoomer]

Looking at the data, I would venture the opinion that the car was on a track day session at some point, possibly a tutored one, say 200 hours ago.

Either the tutor, or the driver under tuition at the time, mis-selected a lower gear and buzzed the engine 3 times on a hot lap or three.

Careless, ham-fisted driving whoever was the perpetrator. These spikes were not hit accelerating up through the gears and missing a gear. This looks like down changes botched.

That's my take on it for what it is worth.

As I said before, the car has run okay for 200 hours since, so forget about it and enjoy your Cayman S........there certainly won't be any cobwebs in your engine!

Brian

 

[paterson12]

That's a pretty plausible theory. As I've said, the previous owner was far from a boy racer.

Im feeling better knowing that 3 ignition strokes equates to milliseconds (if I've got that right ).

Does this date remain on the ECU forever?

 

[ralphmusic]

According to 911virgin..

Range 1: 759 (> 7200 and < 7500) Range 2: 26 (> 7500 and < 7700) Range 3: 16 (> 7700 and < 7900) Range 4: 7 (> 7900 and < 8400) Range 5: 7 (> 8400 and < 9500) Range 6: 3 (> 9500)

and 3 pulses (ignitions per revolution)

I wonder about spurious data logging at least for 4 and above, which is not entirely unknown.

http://www.911virgin.com/...rev-range-information/

 

[ralphmusic]

Does this date remain on the ECU forever?

Yes

 

[paterson12]

Thanks ralphmusic

Forgive my ignorance but is spurious data not unknown?

 

[Boomer_Zoomer]

Ralphmusic may have a point about spurious data. With electronics mysteries do happen.

I could possibly be doubtful of the Range 6 hits. If only by the fact that if you botch a gear downshift to the extent that you buzz the engine to over 9500 rpm, I would have thought that this action would result in the locking up of the rear axle and sending the car into a spin. You wouldn't get away with that 3 times in my opinion.

It's a tricky one to nail.

Oh, just forget it and enjoy your car!

Brian

 

[paterson12]

It's certainly not put me off. One week into Porsche ownership and I'm definitely having fun!

 

[C2dweller]

I review rev range data on a daily basis and I do occassionally see what I term as 'anomalies'... 1's and 2's in higher rev ranges.

I think the inertia of the engine would mean that it is not feasible for the engine to have been there for just the the 8ms (or so) the overrev data would suggest.

When we do see numbers in the higher rev ranges we then look at camshaft deviations to see if there are any tell tale signs of the hard driving.

Your numbers in range 1 are actually very good. I normally say 5-20k is normal on a 60k mileage car (2k engine hours)

Kind Regards Lee

 

[paterson12]

Some very useful information there! I'm actually starting to think range 6 isn't real (frankly, I don't want to believe it). Surely hitting 9500rpm would produce more than 3 ignitions (one revolution), or as Brian said, damage something.

Either way I'm not too concerned now thanks to some great info and opinions from this forum

 

[Motorhead]

Joe,

My take on this is that if the engine has been "buzzed" in the manner described by Brian, you'd be looking at significantly more than 3 over-ranges (equivalent to 1 rev) in range 6. My interpretation of the results is that the 3 over-ranges in range 6 will be included in ranges 1 through 5, etc., so you're looking at only about 5 revs in ranges 3 and above....statistically insignificant??

It seems to me that it's most probably a spurious result and, since the engine has run for 200 hours since the over-rev, the law of averages would indicate that there's nothing to worry about. If the analysis was conducted by a Porsche Centre, the fact that the service advisor showed some concern would be standard practice. Although your car is eligible, Porsche wouldn't grant an Extended Warranty without further examination of the bores and the oil.

I've never before come across a company which appears to place such emphasis rev limit statistics but presume that in the end, it's all down to liabilty - and therefore money..!

Just continue to enjoy the car.

Jeff

 

[paterson12]

Thanks Jeff.

I'm not bothered about the extended warranty so that's not a concerned. Just a shame that this data will 'live' forever with the car as it could give the wrong impression about the way it's been driven.

Have to agree, coming from Mercedes and BMW's ive never heard of a automotive company so concerned about rev limits.

 

[Boomer_Zoomer]

I think that about sorts it, don't you.

Some high quality advice here from all the contributors.

Enjoy your car.

Brian

 

[paterson12]

Some great opinions and information.

Much appreciate, thanks guys!

Joe

 

[Boomer_Zoomer]

You are welcome Joe.

This is what the Forum is about. Helping others.

Brian