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    Problem looming with my C2S

    This is difficult to explain, but hopefully, someone will recognise the symptoms and perhaps steer me in the right direction.

    The car is booked in at the OPC on the 12th December which is a bit of a pain as I have my first UK trackday on the 8th! I might have to give back word at the cost of Pounds150 down the pan, but was hoping someone might be able to offer their experience and help in diagnosing the problem.

    Over the last few weeks an issue has arisen which is progressively getting worse. It relates to either the clutch, gearbox or driveshaft.

    Here's the problem.

    The best way I can reproduce the symptoms are as follows.

    1. Approach a junction in gear as you would do normally, braking until you come to a stop, just dipping the clutch before you stop.

    2. With the clutch still depressed (doh!, obviously ) take it out of gear (it's a manual by the way).

    3. When you release the clutch and just before it is released to the full extent, you feel a thump from behind almost like the driveshaft is engaging, but it's not as the car doesn't stall.

    4. Another way to experience the knock is whist your driving. You change gear as just as before, when the clutch is almost released to the full there is yet again this thump behind.

    5. Selecting a gear from 1st to 4th seems to have gotten a little more notchy also.

    What do you think? Thrust bearing perhaps. The OPC seems to think it's a flywheel issue.

    Of course it will all become apparent when I take the car in, but I'm not so sure it can go another 2 weeks before I'll be ringing Porsche assistance. Oh yeah, the RMS has gone also.

    Any ideas guyz?

    TIA,

    Rich

    Re: Problem looming with my C2S

    Here's what I think is happening. When you depress the clutch and place the transmission in neutral, the clutch plate, the transmission input shaft, and those gears it is driving all come to rest. This is because they are no longer mechanically connected to either the engine or the wheels. Upon releasing the clutch, that entire assemblage is abruptly brought up to speed. This is the 'thunk' you hear. To verify this, try releasing the clutch immediately after shifting into neutral, before the assemblage has time to come to rest. There should be no 'thunk'. If this proves out, but you regard the thunk to be far too pronounced, then I wonder if the damper springs in the dual mass flywheel are intact. They are supposed to cushion this.

    Re: Problem looming with my C2S

    Quote:
    Greentree said:
    Here's what I think is happening. When you depress the clutch and place the transmission in neutral, the clutch plate, the transmission input shaft, and those gears it is driving all come to rest. This is because they are no longer mechanically connected to either the engine or the wheels. Upon releasing the clutch, that entire assemblage is abruptly brought up to speed. This is the 'thunk' you hear. To verify this, try releasing the clutch immediately after shifting into neutral, before the assemblage has time to come to rest. There should be no 'thunk'. If this proves out, but you regard the thunk to be far too pronounced, then I wonder if the damper springs in the dual mass flywheel are intact. They are supposed to cushion this.



    That's what the OPC thinks is happening albeit the flywheel doesn't operate on damper springs aparently. They tell me it's some form of silicone based dampening. Can't see that myself but what do I know.

    Anyway, thanks for the information.

    Re: Problem looming with my C2S

    I tried this on my GT3RS and got no noise.

    Bob

    Re: Problem looming with my C2S

    Quote:
    BobSheeley said:
    I tried this on my GT3RS and got no noise.

    Bob



    That's kind of encouraging in a silly kind of way as it proves to some degree there's definitely something wrong with mine. I managed to pull a bit of a flanker and get my car into a different OPC before my pending track day and get a hire car also. Porsche Assistance...gotta love em.

    Anyway, the car is currently being stripped down to find the problem, even though the OPC has already said they can't find it since their test drive....every time something like this happens I'm sure the dealers first response is this. They are supposed to be Master Technicians these people, and I'm choosing to leave my Pounds70k pride and joy with them.....anyway, I digress.

    As there is a RMS leak they are stripping it down under warrenty anyway, so in the event there is something wrong, which there is, they "should" find it...

    I won't hold my breath though! Fingers X'ed...

    Re: Problem looming with my C2S

    I've never personally seen the Porsche dual mass flywheel, either. All I know about dual mass flywheels is what I've read in the literature.

    I thought they had the rear main seal problem fixed in the 997. Please keep us posted. I'm interested to see what they discover.

    Re: Problem looming with my C2S

    I was expecting the senior technician to come back to me this afternoon as promised but unfortunately that didn't happen. I can only assume that when they took under tray off the transmission fell on the floor....

    It's only been a day and the C class Merc I have on hire is like driving a park bench...

    Re: Problem looming with my C2S

    same thing happens on mine, but I haven't bothered inquiring about it.

    Re: Problem looming with my C2S

    Just had an update from the dealer.

    The transmission has been removed and there is indeed a problem with the dual mass flywheel. The way it was described to me was that there would appear to be too much play, which "could" be the reason I was experiencing the thud from behind when changing gear. They're waiting for a part which should be delivered tomorrow which means I should get my car back, thud and RMS leak free by tomorrow afternoon.

    I must say, the OPC turned this one round very quickly, perhaps I was too quick to judge this particular dealer, so I'll give them the benefit of the doubt. Mind you, trying to chage Pounds1500 for four Michelin PS2's was daylight robery which ever way you look at it.

    Re: Problem looming with my C2S

    1500 British Pounds! That's 3100 US dollars. Man, if they try that here, Pirelli here I come...

    Re: Problem looming with my C2S

    Quote:
    Greentree said:
    1500 British Pounds! That's 3100 US dollars. Man, if they try that here, Pirelli here I come...



    It's true. I had to get Porsche GB involved who assisted me in getting the price down to Pounds1,100, still Pounds150 more than I could have got them for from a local tyre center.

    Re: Problem looming with my C2S

    So why did you let the OPC still overcharge you ?

    Re: Problem looming with my C2S

    I had no choice as "Porsche Assistance" picked the car up due to a puncture and took it to the dealer. Once it was there they said they wouldn't relocate the car again as it "could" be repaired in it's current location.

    Re: Problem looming with my C2S

    What is the final outcome? Did you get the car back? Cross fingers...

    Re: Problem looming with my C2S

    Quote:
    Ferdie said:
    What is the final outcome? Did you get the car back? Cross fingers...



    Nope. They rang me this afternoon, saying the part never arrived this morning. Here we go....

    They have said that the part will arrive first thing tomorrow morning (just like they said yesterday) and that the car will be reassembled before lunch. They'll let me know in the morning... I can but wait and see...

    Re: Problem looming with my C2S

    Well, picked it up today....Chuffed to have it back.

    I think I'm a little paranoid though, as although it feels sooo much better I can still feel a thud from the rear end but only when changing gear from 2nd to 3rd. Well at least I think I can...sending me nuts this.

    Everything else seems okay, albeit the dealer cleaned the car even after being told twice not to.

    I went for a spirited drive this afternoon and it was a very smooth and enjoyable hour. I'm so looking forward to my first track day at Donnington next weekend. Should have a few video's, performance maps and photo's to share.

    Re: Problem looming with my C2S

    ResB I had a flywheel changed under warranty on my old C2S at only 5k miles
    If i remember the car made a very rough grinding sound,a harsh transmision type noise.

    Re: Problem looming with my C2S

    The only thing I can think of would be some sort of excessive clearance in the suspension. The thud occurs when power is applied and the clearance is taken up. You could verify that all suspension components are properly torqued. What about the engine itself? Is its mount points properly torqued?

    Re: Problem looming with my C2S

    Thanks guyz. Well I got the car back as I mentioned but there is still the problem, not as bad granted, but still there and annoying the hell outta me...

    Another trip to the OPC. Whatever happened to quality technicians. I spoke to a local Porsche specialist today and I'm going to take the car to him on Wednesday next week. What a difference. This guy knew so much about the issues I was talking about and I have a good feeling that they'll diagnose the problem as what appears to be just guess work by the OPC...

    Re: Problem looming with my C2S

    I have this problem from time to time too.

    Re: Problem looming with my C2S

    Well I've opted to take the car back to the OPC, but the one I bought it from. Hopefully they should find the fault. Taking it in tomorrow and have a loan car for a few days. Hope it isn't a Cayenne as it cost me a fortune in fuel last time and I only had it a day.

    I would have preferred at this stage to take it to the Porsche Specialist who seem so on the ball, however, any work carried out on the car is covered by the warranty so I have no choice I suppose. If I have no joy this time I think I'll pay for the repair, because there is definately something wrong...

    Re: Problem looming with my C2S

    Just as expected, the OPC had the car for 31/2 days and they couldn't find the fault. Asked them to bleed the clutch at a cost of Pounds50 to see if that would help and picked the car up this morning. Damn thing is still the same, perhaps even worse now. I'm starting to get wound up now, as it's the easiest thing in the world to recreate.

    Deep breaths. They want it back again, but I'm not so sure they know what they are doing, master technicians my @ss.

    Anyway, I'll try to get it to the independent before it goes back to the OPC. This is really starting to frustrate the living daylights out of me. There is definitely something wrong, the symptoms when described to the technicians is met with the same conclusion yet they have done nothing about it...I don't like my pride and joy being poorly. I don't enjoy driving it knowing there is something wrong...

    Re: Problem looming with my C2S

    Can you find somebody else with a similarly equipped 911 and try to reproduce it on that car? Presumeably you've already done that and have isolated the thump to your car specifically.

    What about putting the car up on a rack and while you're in the car operating the clutch, a technician stands below listening for the thump and trying to locate its origin? I don't suppose this could be done with the engine running since the CV joints would be rotating at their maximum angle which is not a good thing. The tech probably wouldn't want to stand under the car with the engine running anyway.

    You're quite sure there's not an object of some kind rolling around causing a thump when it hits a bulkhead?

    It's time to start thinking outside the box. It might not have anything to do with the clutch at all.

    Re: Problem looming with my C2S

    This is pathetic - if its that apparent to you on collecting the car then they should easily be able to hear/feel the fault for themselves - the issue is probably the fact they don't know where to start so it a case of engine out, change something, put it all back and trial.

    If it was really apparent when you collected the car they shouldn't have told you it was fixed and ready for collection. There is an element of them not wanting to carry on with the investigations in all this, as they need to know who will be paying for their time - the warranty from the factory will cover the time, but if its an extended one they might not and the OPC are then left trying to get you to pay for their time.

    I'd at least run it round to an indi to hear the fault and offer some possibilities.

    Re: Problem looming with my C2S

    A man took his new car back to the dealer complaining that it rattled whenever he hit a bump. The mechanic checked everything he could think of, but the car kept coming back --it rattled whenever it hit a bump. This went on for some time. Finally, after a lot of trial and trouble, the rattle seemed to be coming from inside the welded box frame of the car. In desparation, the mechanic cut open the frame, reached inside, and retrieved a large bolt. Attached to the bolt was a paper tag which read, "Bet you played Hell finding this..."

    Re: Problem looming with my C2S

    Just to let you know I've exactly the same gear change issue with my car (997S). I also took it into the dealer and they couldn't find anything wrong with it.

    I get a thump changing down gears from 2nd to 1st. And even a thump if I release the cutch in neutral during the change down (double clutching).

    Re: Problem looming with my C2S

    Do you have the LSD option fitted? Don't know why that would be a problem just checking for similarities.

    Re: Problem looming with my C2S

    Hi guys, thanks for the suggestions and camaraderie.

    Quote:
    Greentree said:
    Can you find somebody else with a similarly equipped 911 and try to reproduce it on that car? Presumeably you've already done that and have isolated the thump to your car specifically.

    What about putting the car up on a rack and while you're in the car operating the clutch, a technician stands below listening for the thump and trying to locate its origin? I don't suppose this could be done with the engine running since the CV joints would be rotating at their maximum angle which is not a good thing. The tech probably wouldn't want to stand under the car with the engine running anyway.

    You're quite sure there's not an object of some kind rolling around causing a thump when it hits a bulkhead?

    It's time to start thinking outside the box. It might not have anything to do with the clutch at all.



    Yeah, I've tried to recreate the problem on another C2S and it doesn't have the same issue. I know this is a problem as mine just started doing it. I'm very sensitive to things not being right and I just know there is something is wrong.

    That's not a bad idea about running the the car elevated but like you say, the CV joints would be put under abnormal conditions which might not be a good thing to do. It would certainly help though if we could do that.

    Definately not a loose object, and definately recreated when the clutch is released.

    Thanks for the suggestions.


    Quote:
    percymon said:
    This is pathetic - if its that apparent to you on collecting the car then they should easily be able to hear/feel the fault for themselves - the issue is probably the fact they don't know where to start so it a case of engine out, change something, put it all back and trial.

    If it was really apparent when you collected the car they shouldn't have told you it was fixed and ready for collection. There is an element of them not wanting to carry on with the investigations in all this, as they need to know who will be paying for their time - the warranty from the factory will cover the time, but if its an extended one they might not and the OPC are then left trying to get you to pay for their time.

    I'd at least run it round to an indi to hear the fault and offer some possibilities.



    You're right of course, and taking the car to the indi is my next step which I'll do as soon as I can but certainy before the 21 January 2008 when the car is back in at the OPC.


    Quote:
    Greentree said:
    A man took his new car back to the dealer complaining that it rattled whenever he hit a bump. The mechanic checked everything he could think of, but the car kept coming back --it rattled whenever it hit a bump. This went on for some time. Finally, after a lot of trial and trouble, the rattle seemed to be coming from inside the welded box frame of the car. In desparation, the mechanic cut open the frame, reached inside, and retrieved a large bolt. Attached to the bolt was a paper tag which read, "Bet you played Hell finding this..."



    Those cheeky Germans... I would have been mad as hell tho'


    Quote:
    Scara said:
    Just to let you know I've exactly the same gear change issue with my car (997S). I also took it into the dealer and they couldn't find anything wrong with it.

    I get a thump changing down gears from 2nd to 1st. And even a thump if I release the cutch in neutral during the change down (double clutching).



    Get it back into the OPC, you never know you might fall lucky and find out what it is, then you can of course let me know.

    Quote:
    Scara said:
    Do you have the LSD option fitted? Don't know why that would be a problem just checking for similarities.



    No LSD fitted.

    I'm on a mission now. This "is" going to get sorted before it really starts giving me a complex. The horrible thing about this whilst I know there is an issue with the car, I can enjoy driving it, almost to the extent if they don't resolve it then I need to get rid of it. Stupid I know but that's how I feel.

    Anyway, enjoy Christmas and the New Year all and I'll keep you updated once the indi has seen it.

    Re: Problem looming with my C2S

    Quote:
    ResB said:
    Quote:
    Greentree said:
    A man took his new car back to the dealer complaining that it rattled whenever he hit a bump. The mechanic checked everything he could think of, but the car kept coming back --it rattled whenever it hit a bump. This went on for some time. Finally, after a lot of trial and trouble, the rattle seemed to be coming from inside the welded box frame of the car. In desparation, the mechanic cut open the frame, reached inside, and retrieved a large bolt. Attached to the bolt was a paper tag which read, "Bet you played Hell finding this..."



    Those cheeky Germans... I would have been mad as hell tho'







    The last time I read that story, the car concerned was a Jaguar.

    Re: Problem looming with my C2S

    Quote:
    fritz said:
    Quote:
    ResB said:
    Quote:
    Greentree said:
    A man took his new car back to the dealer complaining that it rattled whenever he hit a bump. The mechanic checked everything he could think of, but the car kept coming back --it rattled whenever it hit a bump. This went on for some time. Finally, after a lot of trial and trouble, the rattle seemed to be coming from inside the welded box frame of the car. In desparation, the mechanic cut open the frame, reached inside, and retrieved a large bolt. Attached to the bolt was a paper tag which read, "Bet you played Hell finding this..."



    Those cheeky Germans... I would have been mad as hell tho'







    The last time I read that story, the car concerned was a Jaguar.



    Ah,well that explains it.

     
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