zcacogp

Hi, 

My 2.7 987.1 (i.e. non-S) has a problem with starting when it's been left for a while, but works fine at other times. For instance, it had sat in the garage for a week until last Saturday. When I started it then it cranked for a very long time (probably 8-9 seconds) before firing. It fired cleanly with no hesitation and ran perfectly OK from that point on. I drove it for around 10 minutes before stopping to buy some petrol, after which it started again perfectly. I then drove for around 20 miles before stopping for a few hours, after which it fired up perfectly fine again. 

When it eventually started on Saturday it gave me a message on the dashboard saying (something like) "Engine problem, visit workshop", but didn't show an EML on the dashboard. I've plugged a code reader in to it and there are no codes logged. 

The problem therefore seems to be starting it when it's been standing for a period of time. Does anyone have any experience of this or any suggestions as to what could be wrong? 

My thoughts are whether there is a fuel pressure accumulator which holds fuel pressure in the injection rail when the engine is switched off, thus allowing high-pressure fuel to be delivered immediately upon starting. If this leaked over time then it would explain the symptoms, but I don't know whether there is such a thing on a 987 and hence this is guesswork. 

(FWIW I do know that the AOS is leaking and needs to be changed. I have a spare one and will do this job when I can, but other things are preventing me at the moment. I doubt this is relevant but mention it here anyway.)

All suggestions welcomed, thanks. 

Yes, I think that's about it; you can get a 'check box' insurance policy for not very much but you only find out how good it is when or if you come to claim. 

FWIW I went back to Lockton and did a bit of haggling and tweaked the mileage. We're in the mid-£500's now which I'm happy(ish) with. I guess that's for two Porsches, European breakdown cover and excellent service (as I found out when someone made a malicious allegation a couple of years ago). 

Thanks for your help chaps. 

Guys, 

Thanks for the suggestions. 

Lockton (current insurer) have quoted me just over £600 for the 987 Cayman and a 944 which is currently SORN (i.e fire and theft cover only, although any thief who reassembles it enough to push it out of the garage is doing well!) 

A Plan quoted me £460 for just the Cayman. 

The screenscrapers (MoneySupermarket, Compare the Market etc) are coming in just under £300 for the Cayman. 

I am seriously tempted to check the details of the cheaper companies carefully and go with one of them. 

Thanks again for your help. 

Quickie, 

Can anyone recommend a good insurance company or (better) broker? 

The reason I ask is that I have been covered through Lockton who have historically been very good, but their price has increased by over £100 this year. A quick look at the screenscrapers (not that I'd recommend them) is throwing up quotes about half of what Lockton want. 

Who do you use for insurance and would you recommend them? 

(Reference: 48 years old, live in a safe area, car is in a locked garage, NCB longer than your arm etc etc etc). 

Thanks! 

Thanks brillomaster. 

I think that it must use longer-term MPG figures. If it used instantaneous MPG figures then it would drop hugely when starting on a cold day, when the car uses a LOT of petrol to get started and warm up, and then increase massively once it is warm. It does increase when warm but not that much. 

If it used instantaneous figures then it would also show single-digit DTE when you accelerate hard but an almost infinite figure when coasting down a hill; two scenarios which use vast amounts of petrol and no petrol at all respectively. (This can be seen clearly if you drive a car with an 'instantaneous MPG' read-out on the dashboard). In practice it does neither. 

I can understand that it would drop the DTE by a few miles when you do a cold start, as that start uses a quantity of petrol. However the drop of the DTE should correspond fairly closely to miles driven after that if it gets it's maths right. Generally this seems to be the case, but I wondered how it did the calculation. 

Chaps, 

Left-field question here. How does the "Distance until empty" display in the dashboard work? Obviously it tells you how far it thinks you can go on the current tank of fuel but how does it calculate this? It will clearly use an economy figure based upon a number of factors but what are those factors? 

The reason I ask are that it seems to jump around quite a lot. It seems to gently creep up after filling up with petrol and stabilises when the tank is 1/3 to 1/2 empty. However I saw it lose 18 miles in less than 50 yards the other day, just after startup. (This drop was so steep that I turned the car off and checked for a fuel leak. Yes, really.) That was with a 3/4 full tank as well. 

I also did a fairly brisk journey of 100 miles a couple of days ago which cost me over 160 miles in 'distance to empty'. Which seemed a little depressing. 

I can understand that it will probably use a long-term average MPG but how long-term is this? It's NOT the MPG displayed on the dashboard as this is very stable for me, but the 'distance to empty' moves around a lot. 

And what other factors does it use? Temperature? Altitude? Fuel type (from engine knock sensors)? And does resetting the trip reading on the dashboard reset these parameters? 

All thoughts appreciated .... thanks! 

Thanks. 

On 6/17/2022 at 6:41 AM, Paul P said:

... if you are a Porsche Club GB (pcgb) member you can get a fuel card for nothing that’s gets you 5p a litre off Esso supreme.  

 

Really? Care to tell us more? Thanks!

1 hour ago, ½cwt said:

Let's go back to first principles - Boyle's law.

P1/T1 = P2/T2

As the volume is fixed in a tyre it can be discounted, so only temperature or pressure can change.  Thus (working in Kelvin from absolute zero) a 40° rise from say 20 (Typical 'room' temp when considering pressure calculations and is 293K although the temp you set your tyres as is typically lower) to 60 Celsius when the tyre is in use, say on hot tarmac in summer, is in the ratio of 293:333 i.e. approx. 13.5%.  This indicates pressure set at 45psi will rise to approx. 50.85 psi, thus OVER the max pressure the manufacturer of the tyre has stated for safe use and if you se the pressure at 10°C it would be 283:333 which is 17.6% giving nearly 53psi.

I really would recommend NOT doing this.....

 

1 hour ago, CMA said:

Shoulder wear can be caused by more than just tyre pressures.

Taking Michelin, and following their advice, as you say they know tyre pressures better than Porsche, they state here:

https://www.michelin.co.uk/auto/tips-and-advice/advice-auto/the-importance-of-the-correct-tyre-pressure

The correct tyre pressure for your vehicle can normally be found in your owner's manual.

and

If your tyres are over or under inflated enough to be considered un-roadworthy, reading this article could save you 3 penalty points and a fine of up to £2,500 per tyre.

Also you can click through the Michelin site to find their recommended inflation for your specific car, which unsurprisingly matches Porsches recommendation too. Nowhere can I find on Michelins website where it states you should ignore the manufacturers recommendation and set your pressures to 10% less than the Maximum shown on the side of the tyre. So as you say Michelin know their pressures better and yet they recommend the same as Porsche....

Both really interesting, thanks. 

No Michael taking here. I'd start at 45psi and work from there. 

That multi-million pound research you speak of done by the tyre manufacturer will confirm that the tyre is entirely safe to use at 50psi, hence the marking. Tyre wear is something you will learn by your own experimentation but I ALWAYS find that car manufacturer recommended pressures lead to shoulder wear on tyres (i.e under inflated). Comfort is a matter of your own choice entirely. 

Tyre manufacturers know a lot more about tyres and tyre pressures than car manufacturers do. 

I always look at the maximum pressure listed on the sidewall of the tyre, knock off 10% and inflate to that. It will almost always give a higher pressure than 'normal' and it's not always right, but my experience shows that it's a better starting point than those given by the car manufacturer.

You keep a journal? 

I'm impressed! 

😀

FWIW my 944S2 returned more than the standard BHP when rolling roaded at 130,000 miles (219 as opposed to 211). That's now tipped over to 230,000 miles and still pulls like a tart in hot pants at a stag do. It would be interesting to see real world figures for a 987! 

FWIW, the Porsche don't give any different power or torque figures for Sport Chrono equipped cars so I'll be surprised if there is any change to the engine map. However doing a back-to-back run on a rolling road would be very interesting and a good idea. It'll be a slightly expensive way to answer the question though! 

Keep us posted with the results if you ever do this. 

29 minutes ago, phazed said:

As to whether the sport button remaps the engine? Yes, the throttle has a more instant direct feel about it and there is definitely more torque instantly compare to standard mode IMHO. I’m sure I read this officially somewhere a few years back when I first got my Boxster. I may be wrong!

My understanding is otherwise; the Sport mode on the 987.1 only remaps the throttle pedal but does nothing to the engine map. A gentle push in Sport mode gives the same signals to the ECU as a firmer push in Normal mode. However, as you said, I could be wrong too! 

Surely it could only speed up the steering if there was a variable ratio rack, which isn't something I've ever heard of?

On 5/17/2022 at 10:52 PM, Paul P said:

Cheap reader is like a tyre pressure gauge these days - basic tool in the glovebox. 

Ain't dat de truth, brudder! 

I was thinking precisely the same on Sunday afternoon when I plugged my code reader in to turn off the airbag light. I knew why it was on (I had disconnected the driver's door airbag without disconnecting the battery first) and knew that solving the problem was as simple as plugging the machine in and clearing the codes. 

If you have a 987 and don't have a fault code reader then it's worth getting one, even if it is only a five pound bluetooth one from eBay (as linked above by CodFanglers). 

Greyanglia, all the best with solving your problem. As has already been offered, you are more than welcome here for a coffee and a code read but I'm in GL50 which is a bit further from you. 

2 minutes ago, phazed said:

Ditto.

Sport Chrono Package 

(Button Marked “SPORT”) 

Time is precious and every hundredth of a second counts. The optional Sport Chrono Package makes your driving experience priceless thanks to an even sportier tuning of throttle response and handling characteristics.

The package comprises dynamic gearbox mounts, a performance display, a digital and analogue stopwatch and the SPORT PLUS button. When this is pressed, optional Porsche Active Suspension Management (PASM) switches to ‘Sport’ mode for harder damping and more direct steering and therefore, even more intensive road holding.

The trigger threshold for PSM is raised. Agility is perceptibly enhanced when braking for corners with PSM, allowing even sportier braking and exit acceleration. For even greater dexterity, PSM can be set to standby while the car is still in SPORT PLUS mode. For safety, it is set to intervene automatically only when ABS assistance is required.

In conjunction with optional PDK, the Sport Chrono Package comes with two additional functions for a sporty drive that borders on a motorsport experience. The first is ‘Launch Control’, which is designed to produce a racing start.

The second function is the involving ‘motorsport-derived gearshift strategy’. Using this, Porsche Doppelkupplung (PDK) is geared up for the shortest possible shift times and optimum shift points, while torque boosts during gear changes provide the maximum acceleration available. This involving experience is further enhanced by overrun downshifts and the throttle-blip function for uncompromising driving pleasure.

An additional display in the steering wheel or either the instrument cluster indicates the SPORT or SPORT PLUS buttons and, with PDK, Launch Control have been activated. In conjunction with the optional Porsche Communication Management (PCM), a special display enables you to view, store and evaluate lap times or other driving times. It shows the total driving time, lap distance, lap number and lap times recorded so far.

This will be a description of the 987.2, on which the Sport Chrono system did more. 

1 hour ago, Menoporsche said:

Sorry, is this PASM in sport mode (stiffer suspension) or the Boxster in sport mode (tighter throttle response, delayed PSM intervention)?  Or does switching PASM to sport effectively switch the ECU to sport to also affect throttle and braking?

What Phazed said ^^^^^. 

PASM is separate to Sport Chrono (I think that they could be ordered separately but am not 100% on this). 

On the 987.1 Sport Chrono models, putting it into 'Sport' mode would put PASM into 'Sport' mode, adjust the throttle response, back off the PSM slightly and make the gearshifts quicker (if you had a tiptronic model). 

If you put the car into 'Sport' mode then you can subsequently put the PASM back into 'Normal' mode, giving you the crisper throttle response and backed-off PSM with the more comfortable suspension. 

You could separately put the PASM into 'Sport' mode giving you the spine-jarring suspension with soft throttle response and uber-nannying PSM. 

Phazed, as far as I'm aware Sport mode changes the throttle pedal map but nothing else, so there is no difference in the power or torque curves. It just had the effect of pushing the throttle pedal harder - i.e small pedal movements are read as large pedal movements. 

However I do agree that the effect is quite remarkable. (Whether it's desirable or not is another matter and there's been much typing wasted debating that point on other pages on here.)

Thanks PaulP and gillbe, both of those are really interesting answers. I fully understand the logic that the plates do something and are worth the money that Porsche spent on fitting them. The question of whether that benefit is applicable to me or not is the relevant one; for instance I will never use the ISOFIX child seat mounting points on any car as I have no kids but they have been installed on a number of cars I have owned. 

The notion that they help keeping water off disks is very interesting and I'd not argue the point with Porsche. Thanks for the info gillbe. 

As Phazed said, Sport mode backs off the PSM slightly as well as sharpening up the throttle pedal response. And if you have a tiptronic/DSG car then it speeds up the gearchange too. At least, this is what happens on a car with Sport Chrono - was it possible to order PASM without Sport Chrono?

2 hours ago, ½cwt said:

When the car is on axle stands, use the jack to raise the hub protect the bottom of the coffin arm,  until the weight just comes off the stsnd, you are then near if not exactly at z=0.

Thanks. I'll put this on my list of things to do this week. 

5 minutes ago, ½cwt said:

@zcacogp not so critical on the coffin arm to tuning fork bolts, but did you torque them up (160Nm/118lbft) with the suspension at the normally loaded position (Z=0) i.e. not on full droop when jacked up.  This is essential for the coffin arm to subframe bolts otherwise you'll damage the rubber bushes between the inner metal bush and the arms by preloading them.

Good Q and I didn't know that this was a requirement. No, I didn't! 

How do you do this for any of the bolts without a pit (or hoist that lifts the car on it's wheels)? If it's sitting on it's wheels there there isn't space to get in to the do the job, is there? 

On 5/21/2022 at 2:19 PM, bally4563 said:

... magnetic fluid in the shocks ...

I didn't think that the 9*7 DSC-equipped cars had magnetic fluid in their shocks; I thought that the adjustment was done with variable-orifice valves. Am I wrong?