Engine cutting out/rough idle

Having enjoyed 4 months and 5000 trouble free miles with my 996, it was time for a service. For peace of mind, I decided to proceed with the 48000 mile major service (although it had only done 33000 miles) as it didn't appear to have had its spark plugs changed last time. Bolton Porsche therefore carried out:- full major service, 2 new rear tyres, rear discs and pads, 4 wheel alignment, RMS seal replaced under parts warranty (having been done 2 years ago at Kendal) and 2 variocam seals, replaced FOC in view of the spark plug change. Total cost £2200 with impeccable customer service and a 400 mile old Boxster S courtesy car. Having collected the car Wednesday evening, after driving it just 2 miles the engine cut out at a junction. It cut out again closer to home - in the middle of a roundabout! I rang Bolton the next day and arranged to return the car Friday. It cut out 6 times in total over 7 journeys and the idle was rough. On Friday I had 200 mile old Boxster S courtesy car and the car was booked in until today. On Friday afternoon I was telephoned to be told my car was ready, that they had incorrectly programmed the computer for a pre facelift car which has a different idle speed due to it having a different alternator and that all was well. I collected my car back Saturday. It was clear on Saturday that all was not well, the idle was rough and at times the whole car was vibrating on idle. This morning, the car cut out again.and frequently when slowing to a stop, the engine speed would die down to 400 rpm before picking up and the idle settling down. Before I ring Bolton again, I wondered if anybody else has experienced anything similar or had any ideas. The car ran perfectly beforehand and has never done this before. Many thanks.

£2200 - Ouch! I don't believe it is possible to reprogram the DME, and they certainly would not have to program anything during the service - just read out the faults. Idle speed different due to different alternators - Tosh! It sounds to me like your MAF sensor is on the way out, or possibly the throttle body actuator. Edit: and idle speeds for non-egas and egas cars is 680 and 700 rpm respectively.

Thanks Richard. I thought as much having looked at some previous threads but it strikes me as beyond coincidence that the fault first appeared less than 2 minutes after it left the dealership?

Try checking the connection on the MAF. It's on top of the air box. Maybe they disconnected it to change the filter, and didn't plug it on properly afterwards.

Thanks again Richard. Had a quick look but couldnt see anything obvious. The saga has gone from bad to worse... car went back in last Tuesday (back in the first Boxster S which I became quite fond of) with an assurance that it would come back sorted. Didn't hear anything until Friday when I got a call to say the car was being delivered back to me. Apparently after much checking, the culprit for the rough idle was a pin hole in a vacuum pipe to the breather which had now been replaced. Car arrived at work (cleaned again) and the driver assured me it was driving right this time having not been right when he took it on the Tuesday. I drove it home - 5 miles - Friday night and it seemed fine. The end... Not yet! Started the car on Saturday afternoon and smoke started pouring out like James Bond had hit the smoke screen button. Quickly turned it off and rang Bolton for help but, not unreasonably, service was closed. I was promised a call first thing Monday morning and to their great credit, I was phoned by 8.15 Monday and within 2 hours both the service manager and the senior technician arrived at my house. After a quick try it was clear that all was not well and arrangements were made for the car to be trailered away and I was left with another new courtesy car. I was phoned this morning to be told that there was a fault on the breather, the part had been ordered and the engine has to be removed to fit it and that I should have the car back by Friday. Bolton OPC have suggested that the failure of the breather could be an unfortunate coincidence but conceded that it may have been disturbed when the engine was removed for the new RMS last week. Have to say that Bolton OPC have been extremely helpful but my honeymoon period with my 996 is being tested. Watch this space...

When they say breather, I assume they mean the oil separator, and I'm not sure the engine has to come out to replace it. One of the Tipec chaps (PiG) posted a message on Renntech saying that he had done it without removing the engine: http://www.renntech.org/forums/index.php?s=&showtopic=12052&view=findpost&p=58902 Trouble is that an OPC will do it by the book. Is it under warranty?

was only explained to me as a breather but then my mechanical knowledge is not exactly extensive. had always thought that the extended warranty was very expensive insurance - for less money my comprehensive road traffic policy covers me for a couple of million pounds - the car came from a highly regarded club member and other members had known the car for some time so thought I'd take the risk...

I just thought that if you had the warranty it wouldn't be an issue, otherwise you could have taken it to an independent and get it done much cheaper.

In November my car had a 48.000 mile service and the revs would stick at 1400 revs until you pressed the accelrator they would then drop went back twice they kept it in, got it sorted and then told me on the phone that they had a problem with it cutting out, they got it sorted in the end i was told that it had to be re-calibrated, Porsche Germany had to send some codes to do this apparantly. Whatever they did it seams to have done the job. Phil

well, my car was returned today. not just cleaned this time but professionally valeted inside and out. the explanation given, which i confess to not fully understanding goes like this: having removed the engine to replace the breather, the smoking fault remained, Bolton OPC therefore concluded that the fault was not with the breather. as the fault only became apparent after they replaced the pipe to the breather with the hole in it, it had to be something related to that so they removed it. hey presto, smoking problem solved. this however brought the rough idle problem back to life. they therefore looked to what the pipe was connected to - described as some form of electronic switch - which they swapped with a carrera 4 they have for sale and suddenly everything was ok. They think that the hole in the pipe was not in fact caused by them when they replaced the RMS but had been done deliberately as a form of bodge repair in the past which I think is a bit odd as the car has only ever been looked after before by an OPC. They think that they have found a hidden fault with the car that neither of us previously knew about and clearly have gone to great lengths to fix it. I have not been asked for a penny since the original service bill was paid, the car has subsequently spent 11 days with them and i now have a new oil separator. I would be fascinated to learn what forum experts think of the diagnosis although I am so pleased to have my car back both running better than it ever has and looking better than it ever has that i intend just to enjoy it again! Whatever the problem was and however it arose, Bolton OPC ensured I didn't get it back until it was fully sorted, i suspect at considerable expense to themselves and all they did was apologise for the inconvenience caused to me and they even returned my car with more fuel in it than it went back with. [ ][ ][ ]

Sounds like a good ending, i am pleased that they looked after you so well, worth it as you will go back. Phil

a couple of days on and all is well, as was clear from the moment I drove it again on Friday. Mike, the service manager from Bolton even rang me on Monday morning to check that everything was ok. As a fellow 996 club member has remarked to me, it is rare to get this level of service from any organisation these days, let alone a car dealership.

Thought I'd bring this thread back to life in view of what happened on Friday night... Coincidence? Had used the car lightly for a couple of weeks, after a great trouble free trip to the North East as it's due a service this week. Decided to treat myself on Friday and took the car to work, no sign of any trouble. Heading home, about 25 minutes into the journey I had the choice - slow road to the supermarket to pick tea up or a quick blast up the dual carriageway. Traffic was light and I thought it would do me and the car good to take the long way round. At the roundabout half way along I was in the outside lane, a Mazda MX5 took something approximating the racing line right in front of me then pulled back into the nearside lane so I couldn't resist, floored it in second then third past the MX5,gently into fourth, gearchange was a bit rough which I thought must have been me, into 5th, rougher change, not down to me, into 6th, no acceleration. Checked the mirror to see a thick fog of whiteish smoke behind me, the dashboard then lit up like a Christmas tree, low oil pressure light on, engine off and coasted to a halt with smoke pouring out of the vents on the engine cover and a line of oil up the road behind me and a growing puddle under the car. A kindly passing motorist took pity on me and helped push the car to safety (the others were too busy laughing) and the RAC brought it home. There is no coolant left in it, the back of the car was coated in oil and I can't tell how much oil is left in it as I can't get the dipstick out and the electronic display says oil level measurement failure. Bolton OPC have booked it in for Tuesday for assessment. Glad I don't have a warranty [ ]

Sorry to hear of the tale of woe Rob. Don't forget the KY jelly when you go to OPC Bolton. Cheers,

Sorry to hear this Rob, as it sounds expensive to me. Clouds of white/blueish smoke might have pointed to an air/oil separator failure, but no coolant and a big puddle of oil......... I think I'd be more tempted to take it to Hartech.

Oh Rob! Really sorry to hear this. My fingers are crossed that it will turn to be less expensive than it sounds.

Hartech website seems to suggest that Porsche may make goodwill contribution if vehicle has done under 50k miles - mine has just done 44k. Will see what happens, thanks for the support!

Sorry to hear the bad news Rob, I'm sure OPC Bolton will at least make a goodwill gesture towards anything that needs doing or maybe more. Fingers crossed for you.

Well, the car was trailered to Bolton yesterday afternoon within 90 minutes of the Service Manager learning of my woes which was impressive. Initial diagnosis is that there is no obvious external damage but the dipstick can't be removed which is not a good sign. Bolton suggest that to remove and strip the engine is 36 hours work although the problem may emerge before it is fully stripped. There seems to be a chicken and egg situation in that they can't approach Porsche for a goodwill gesture until they know what's wrong with it. Obviously I want to avoid throwing good money after bad and if there is clearly major internal damage then I don't want to pay to strip it. Bolton are looking for a solution...

IMO they know the engine is lunched. It doesn't matter if it's a failed IMS or cracked cylinder it's still lunched. Charging you 36 hours of labour (>£4.5k) for a chance you may get 50% goodwill on a refurbed engine isn't worth it. Used engines can be had for under £4k. If they come back to you with 'What's it gonna be sir, 36 hours labour and some goodwill or you take your car away' I'd take my car to Hartech or Autofarm. So far they have tried to do the right thing. Le'ts hope they come back with a better offer. Good luck Rob.

Rob, Why not have a word with Phil Clark and see what he says? Email me if you want his number. Cheers,

I tend to agree with Rodney, but I would have thought that a decent outfit would be able to determine a lot more before stripping the engine. Does the engine turn by hand? Have they pressure checked the cooling system? Have they tried a cylinder leakage test? It wouldn't cost that migh to pull out the plugs and pop an endoscope into the cylinders. It should be standard equipment in an OPC workshop.

Fred, I've spoken with Phil - he's on standby for me if there is no goodwill offer and agreed that Bolton should have a look at it initially as if he stripped it down the chance of goodwill disappears. Update is Bolton will take the engine out and we can make a decision then whether or not it will need stripping - I can certainly ask them to do what Richard has suggested if all is not clear at that stage but agree with Rodney that there is a certain inevitability that the engine is lunched!

Well is it fixed or in the grave yard, head stone to read.. Here and not forgotten, My darling half shaft as broken in three, Oil and water everywhere, Should have bought a 993

or a warrantee... yeah, thanks Barry! Think Phil was taking a peek at it on Friday whilst he was there on other business. Went to see what was left of the engine on Thursday with Steve Webb, dealer principal at Bolton. Engine had been laid out on cardboard in the workshop for viewing. Think I share his view that nobody will ever be able to say why it let go. There is only one piston left! The outer casing is smashed, there is damage to the clutch, flywheel, starter motor, everything really. Some heat damage evident on a bit of the intermediate shaft but it's like a bomb went off in there. Currently waiting to hear if Porsche will offer any goodwill, otherwise Bolton want about £10k subject to what else they find...

Ouch!! Not good news Rob. Have you looked around the breakers (Simon etc) to see if there are any engines available? Cheers,

Phil Clark made a call for me but not sure who to. Am sure Phil can souce one if necessary. Still waiting to hear from Porsche, my final hope... Got an email from Honest John of The Telegraph motoring section today, perhaps he can shame them into doing something! Was offered a generous [ ] £23500 as a part ex valuation if I buy a new car... once it's fixed! At least Dick Turpin wore a mask. I am completely and utterly disillusioned by the whole affair.

Did you offer to be their defence in court when they are brought up on charges of highway robbery? I think Phil is your best chance. I don't know how the OPCs stay in business. May see you at the meeting on Wednesday night. You can tell Zeb all about the woes of 996 ownership whilst I extol the virtues of 964 motoring. Cheers,

Sorry to hear of the tale of Woe! Sounds frightening! Good luck with the outcome and your right to ask advice on the forum!

Crikey - bad news ... Surely there is is technically possible that whatever they messed up at the service - which causing the rough running - meant extra strain was put on the internals which was a contributory factor the the subsequent failure. Seems too much of co-incidence to me. I seem to remember, somewhere in the depths of hartech's web site, something about poor idling putting strain on thigs. Might be worth pursuing.(*) Other thought is getting Baz at hartech to look at it to see what his repair would cost - could be a lot cheaper than Bolton OPC. (*) Edited to add: just spotted you specialise in criminal and motoring law ... sounds like you have the right qualificiations to take Bolton to court over this ...

Rob, You have my sympathy too;Diesel130 makes a good point,how an engine can implode without having had symptoms showing up on the analysis equipment or detected by experienced technicians beats me.What happened to all the work put in by Ralph Nader;everything points to manufacturing/design faults with this engine,given all the history available on this forum. Probably see you Wed. Cheers, Colin.

If someone from Bolton OPC turned up at the meeting we could have a public hanging in the car park. I understand it is still legal in Garstang. Or if it is cold a burning at the stake. Cheers,

Good luck Rob - i think you have a better chance than most given the history of the car and your relationship with Bolton OPC - lets hope they do the right thing and sort it at minimal cost to you, or worst case, the same as taking it to Hartech.

Many thanks guys. I couldn't agree more with Diesel130. It's all too much of a coincidence. Really don't want it to end up at Court though - like to keep work and play time separate! Am told Porsche GB will be in touch tomorrow, the person dealing with it was off today so my fingers are firmly crossed.

Fingers crossed for you Rob, hope for the best!

Good luck Rob - I hope the outcome is a pleasant one!