Porsche Enthusiasts Club Forum

The goods news is I picked up my GTS today, bad news is I got stuck in a long traffic jam coming back and the clutch/gearbox started making a horrible whining noise,, appeared to come from almost directly under the gear stick?. Once we got moving properly again it didn't do it again so I'm not sure if this was heat related or due to lack of regular use. A couple of minor things need sorting, interior light comes on when door closed and goes off when the door is opened? Really needs a new carpet for the luggage area as the backing has started to fall off and also the dreaded tail gate release.
When I first got home I went to open the boot, which had opened fine when I first looked at the car, solenoid/motor whirred but boot didn't release then the solenoid/motor stopped whirring as well. I got it open using the key but that was really stiff, which parts are a) available & b) likely to need replacing to get it working again, anyone know?
One last thing a couple of times a message came up on the dash saying ' Differential control off', any idea's on that one folks?:)

Hi

Ok..in reverse order as easiest first....

The dash message about diff control....

On a GTS you have an electronically controlled limited slip diff of a sort called a "PSD"

That message is saying its not working for some reason.......although it will not affect your driving in any way, as like any lsd it only NEEDS to work in extreme circumstances, such as on a track or on ice etc when the back end loses grip badly....

You will need to get it checked with a Porsche dealer who can plug in a tool to check its fault reading.....or if near Paul Anderson, he will be half the price and twice the quality....

Ok...next...

Hatch release... this one happens to ALL of us sooner or later, and quite often as well lol

The nylon insert is worn and needs replacing, until recently you had to buy a whole lock receiver at around £80 ask how I know

You can now get the nylon insert only from Roger at 928RUS in Texas (hes british) and a REALLY good guy....

Interior lights ..how MANY work and what do they do ??? there are 5 by the way ???

Clutch ...need to see if it happens again as it may well not occur again if it has been parked up for a long period...

Hope this helps

All the best Brett

Well the gearbox is at the rear, so it's less likely to be that (wouldn't hurt to find out when the oil in the gearbox was last checked/replaced), if the noise is from the front then perhaps a torque tube bearing or something in the clutch - does the noise change depending on whether or not the clutch is engaged?



The interior lights usually have a three-position switch, off all the time, on all the time and on only when the doors are open (on the later cars the light also stays on for a period after the doors have been closed, unless you lock the car) I can't remember which order though, you'll have to experiment; see if the same behaviour is exhibited by all your interior lights (roof, footwells and tailgate) - if it's just one light then it's probably been wired incorrectly, if it's all the lights then the fault is somewhere else (and does it make a difference which door is opened - might be the door switch?).



The lock is probably just stiff from lack of use if the electronic mechanism had previously been used all the time; if the motor turns but the hatch doesn't open it's usually caused by the plastic "liner" to the lower part having broken up through age, for most people this means the mechanism needs adjustment/shimming as you can only buy the lower assembly complete and it's quite expensive; if the motor is no longer whirring it may just be the fuse has blown.

Just seen Brett's reply - I'm not sure whether Roger still does the replacement inserts?



It means that the PSD has sensed an error, this is commonly (but not always) caused by a faulty/marginal ABS sensor, since the PSD and ABS systems are interlinked.

I'm sorry you're having so many problems, it must be very frustrating for so many unknown things to appear so soon - if you bought the car from a dealer (which I believe you did?) perhaps you can get them to fix the faults.

If there's an ABS sensor fault you would get a simultaneous warning light for ABS and the RDK (tyre pressure monitor).

If the ABS is working ok then PSD warnings are problem with pressure system/pump/switch. It may just need fluid change and flush (should be done every 2 years). When was fluid last flushed?

The workshop manual has a complete section (Vol III, D39-201) on troubleshooting the system, but the fault codes will be stored and can be read out with a Bosch Hammer, which all OPCs and any proper independent will have. The RDK system must be connected to be able to read the faults (sometimes the RDK system is disabled if an owner is irritated by spurious pressure warnings - it's very sensitive).

When you turn ignition key to run can you hear whine at rear left for a few seconds as PSD accumulator is charged by pump, then pump cut off by pressure switch?

If you accelerate hard on damp road does the green PSD light flicker on? If so the PSD controller is working correctly.

If you brake hard does ABS function (confirms ABS sensors ok)?

The PSD system is far superior to earlier LSD, but is quite exotic in terms of its operation (I think there are even inclinometers involved to sense rear wheel angles!). That's why fault code reading with Bosch Hammer is best approach.

Actually sounds like you have relatively few problems for a 'new' 928. The lights/hatch stuff is routine and can be sorted later.

Am a little concerned that car was described as "director's personal car". This is ruse traders use to evade responsibility under used car warranty obligations, by registering it as private not trade sale. First call is to get Bond St to fix the problems (no way will they have a Bosch Hammer or even know there way round psd, but they should be repsonsible for paying for faults to be rectified).

Whilst these things are disappointing the car was registered privately to one of the directors at the garage for the past 5 years, and he is a genuine 928 enthusiast who also races a 928, who I've spoken to at some length. He's away at the moment so I shall discuss things with him when he gets back and I'm sure they'll sort things out, I just thought I'd ask so that I had some idea of what I was talking about.
The interior light that's playing up is the one in the centre of the roof at the front, the others come on and off as they should but this light comes on when you shut the door and goes off when you open it!, I've tried it in all positions.
I think you could be right about the PSD system needing to be flushed and I shall enquire as to when it was last done. The whining noise wnet in tandem with the movement of the gear stick, i.e. when you had the clutch depressed it made a noise but as you moved the gear stick to take a gear it got worse, then once out of the traffic jam it didn't do it again. A friend of a friend has a Bosch Hammer so I'm planning on taking the car to him and getting a diagnostic check done on it before going back to the garage.
It makes it sound like a right pile of dog do but I think it's mainly niggling little things through lack of use, at least I hope so, and once sorted and used more frequently it should be o.k. I did wince a couple of times when going through the service history to see service bills at OPC's of between £1200 & £4000,

This does not sound too bad, when I collected my £5,000 ebay purchase 928 the cam belt warning came on and stayed on all the way up the M1.
Had the engine blown up in the contraflow (which went on for over 20 miles) I'd have been tempted to get out and run away!!
I got home OK but within a week the sump gasket failed which eventually cost me £1,000 as there were other things to do such as retensioning the cam belt. Soon after that the aircon packed up (£650) the gear shifter fell off (£170) new sidelights were needed (£300) and a new headlamp relay (£90) but hey, the car is 20 years old. My friend's Fiat Punto Sporting went to the scrapper at 10.

Sounds reassuring about the previous owner.

Doesn't sound like a dog in the least - apart from the gearbox/torque tube whine these are typical issues on most 928s which have not been fastidiously maintained.

Excellent that other interior lights are fine. The roof light may have been replaced in past and the connectors put back in wrong order so just pop it out of roof lining and check the connectors at one end (there are 3 wires to it). Red wire connects direct to bulb, brown wire to the fixture frame, brown/white wire to the switched connection. Alternatively the light has simply melted (very common if left on) and contacts shorted internally. Just replace with a new light - they are fairly cheap. Part no 911.632.102.00 so as shared with other Porsches easy to source as 928 parts go. The light is always supplied with 12V and is grounded by a door/hatch pin switch to turn on. If a door switch was permanently grounded all interior lights would be on in the 'auto' position, and you would also drain battery very fast as the red marker lights in door frame would be permanently on.

Great news that you know someone with a Hammer. As well as reading PSD faults it will also run a health check on all key actuators and sensors for the injection/ignition brains. All these items can be checked manually but the Bosch tool is much faster. I have the John Speake equivalent which is a handy piece of kit, but it can't diagnose the PSD or control a PSD flush procedure.

If I bought a £5000 S4 off ebay I would expect there to be things wrong with it that the seller either "forgot" to mention or wasn't aware was a problem.

If I was paying two or three times that for a car from a professional dealer or enthusiast I would have expected them to point out any known "niggles", and if the car had been continuously well maintained I would have been unhappy to have found three or four things (no matter how minor) suddenly going wrong before I'd even got the car home, regardless of how old it was.

But maybe that's just me

No I agree with you, I was a bit disappointed to have bills for £2000 within a month of buying my car, but was expecting some work due to its age. I would have been more upset had I paid £10,000 plus though, but the 928 is well known for this. The fourth owner of my car (1997-1999) paid nearly £17k for it in 1997, when it was only 8 years old. It cost him £12,000 in repairs and maintenance over the 18 months that he owned it.

I'm in a classic car club that caters for all types of car, and it seems fairly normal to spend money on a "classic" car when you first buy it, no matter how good it seems to be. My last car was a 1932 Standard Little Nine, bought from a dealer. It was described as having had a "full and exacting restoration to the highest possible standards" and was not cheap. The body and interior were flawless but it took me hundreds of hours of work to get the mechanical/electrical parts right. (although to look at everything was perfect, none of it worked properly)

Perhaps I should have taken heed of the warning from the aforementioned noise coming from the clutch (although to be fair it hadn't made the same horrible shrieking noise since the day I picked it up), I went out this afternoon and went to change form 3rd to fourth and it didn't want to go. It wouldn't go back into 3rd either so after a few yards of coasting along it went into fifth, approached a roundabout to turn and head for home went down into 3rd at about 50 mph and the gear stick started shaking like a Chivers jelly. I got home with a combination of slow gear changes and strange noises coming from the clutch and it's now parked up in my garage.
In fairness to the dealer I bought it from I phoned them when I got home and straight away they said they will send a transporter down to pick it up on Monday and take it back and carry out any necessary repairs, they also offered to bring a loan car down but as it's not a daily driver I didn't need it, and then bring it back once done.
It's just sad that on the one decent afternoon of the week that I could take it out, and so soon after buying it, something presumably quite major has gone wrong. The other sad part of that is that next week is my last week off before I start a new job and I was hoping to get out in it a few times but I doubt I'll see it back before the end of the week.
I know analysis is difficult without driving/hearing it but does anybody have any thoguths as to whether it may simply be the clutch and nothing more sinister?

And will the trader also be investigating the PSD warning problem?

I am a little wary that they are so keen to make amends. They must have been aware of the gearbox problem before the sale, so why didn't they fix it then, especially if the car was being regularly used by one of the proprietors?

Why hadn't they foxed the simple fault with the courtest light connections? Again if car was being used then it would have been draining battery whenever it was left for more than a couple of days!

What dos their warranty actually say in terms of who can do any remedial work? A lovely GTS manual should be in the hands of a Porsche specialist at least, but preferably a 928 specialist.

Well, it's possible that the faults were not there when they last used it. The seller of my 928 claimed that the cam belt warning never came on for him (and he offered to sort it for me but it was too far to go back)
Last week the torque converter failed on mine, there was no warning, it was OK the day before. Maybe the clutch did the same on that GTS. As for warning lights coming on, I thought that was par for the course with 928's!

If the garage are offering to sort it, and even to send a transporter for it, I would say that there is nothing to worry about.

Possible, but a major coincidence that the first thing he should notice on driving back from trader was gearbox noise. Just saying.

To be fair I told them about the noise from the clutch on my return journey and they said to monitor it and if it continued they would sort it out, the shrieking noise had not re-occured since. I then noticed what sounded to me, with little knowledge of 928's but having worked on other cars, like the release bearing grumbling a few days ago, it had been driving fine the last time I drove it on Thursday. You could only hear the bearing noise if you put the window down and depressed the clutch for several seconds, in normal driving you couldn't hear it.
On speaking to the garage yesterday there was not the slightest hesitation in saying that they would arrange collection and repair and that it would go to the local independent Porsche specialist for, who I believe is GCR at Wigston, for the repairs.
Yes it's very disappointing that this has happened, I have no reason to believe that they were aware of it before I bought it, and the people at Bond Street have given me no indication that they are anything other than helpful straight up people. The previous owner who is a Director of the garage is a Porsche enthusiast who races a 928 and owns a late 911 Turbo for road use so I remain hopefully that my impression of them is well founded.

That's encouraging - I remember seeing some very positive remarks about GCR on other forums so hope all sorted soon to your satisfaction.