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  • Roadster Coupe Gearbox woes..

    Seems to be a common problem, car comes to a halt, go to pull away and no gears selected, 3 bars shown on dash display. The local independant smart place changed a sensor (cheapest 'maybe' cause first they said) car went fine for a while then same again, (disconnecting battery for a few seconds also seems to work.. Green Flag guy did that)
    Back to the garage and they are trying to get hold of a new gearbox.. would this be the next logical step?
    Just a bit concerned about the price!

  • #2
    Re: Roadster Coupe Gearbox woes..

    I think you need to find a new garage, pronto. It'll be wiring problems, chaffed or stretched. Mark @ fudgesmart normally works these out quite well.

    Comment


    • #3
      Re: Roadster Coupe Gearbox woes..

      Originally posted by europas2 View Post
      Back to the garage and they are trying to get hold of a new gearbox.. would this be the next logical step?
      Illogical in the extreme. Your problem is electrical. As Ant suggests, get the car to someone who knows smarts. And go easy on the battery disconnects or there's a strong chance the car will refuse even to start.

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      • #4
        Re: Roadster Coupe Gearbox woes..

        gearbox will not be cheap!

        If they are a true smart specialist they should have star diagnostics which should tell them what the fault is or at least a very good idea.....
        To just guess and replace parts willy nilly sounds a bit amateurish and a way to get money out of you time after time....

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        • #5
          Re: Roadster Coupe Gearbox woes..

          New gearbox will cost some serious bucks. A good diagnostic session will point in the right direction to the fault/s.

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          • #6
            Re: Roadster Coupe Gearbox woes..

            If I could have £1 for everytime I have heard this story I'd be able to afford some nice upgrades for my Roadster by now.

            It WON'T need a new gearbox. Anyone calling themselves a "Smart Specialist" and handing out this advice needs to hang their head in shame.

            As has been pointed out - the most likely cause will be chaffed wiring where it passes the intercooler air scoop. There are other possible causes but this is the first place any self-respecting smart specialist should be looking.

            Does your problem occur mostly when the roads are wet by any chance?

            Comment


            • #7
              Re: Roadster Coupe Gearbox woes..

              from memory maybe when it was wet, its the other half's car, the last time it happened I was called out to meet her with food!
              I thought the new gearbox thing was a bit extreme.. had a look on fudge's website and it looks like my smart guy may not have the better code reader, they had it for a while to drive and see if it failed, then check 'stuff', when we spoke he said it could be a number of things. Fudge's site says it can be pinpointed with the reader.. (even dodgy wiring ??)

              Anyway, were taking the car back later today. Is the wiring easy to access to check? something I can do myself? (quite handy with old cars.. not so with new as they need special tools)

              Is a star diagnostics system within the reach (financial) of a home mechanic?

              cheers
              Last edited by europas2; 21-02-14, 10:04 AM.

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              • #8
                Re: Roadster Coupe Gearbox woes..

                Originally posted by europas2 View Post
                from memory maybe when it was wet,
                In which case suspect the wiring first.

                Originally posted by europas2 View Post
                Anyway, were taking the car back later today. Is the wiring easy to access to check? something I can do myself? (quite handy with old cars.. not so with new as they need special tools)
                On a fortwo (don't know if it's the same for a Roadster - see Evilution and/or FQ101 for more info) jacking the rear left corner, removing the wheel, and IIRC, removing the inner wheel arch allows access. It's then a case of locating the bundle of wires that lead to the gear position sensor and gear selector motor. They run very close to (usually touching) the intercooler air scoop. Checking them is a visual and/or continuity check. Pretty sure they can be damaged sufficiently to require nothing beyond eyeballing. When done, put something soft (eg lump of stiffish foam) between them and the IC scoop.
                If the wiring is all OK, then the two components mentioned above are suspect - though you may have had one of them (the position indicator more likely, being the cheaper of the two) replaced already.

                Originally posted by europas2 View Post
                Is a star diagnostics system within the reach (financial) of a home mechanic?

                cheers
                The answer to that I think is no. It's expensive to buy into and requires IIRC a renewable subscription. Others can advise better - including on cheaper (counterfeit?) alternatives.

                Comment


                • #9
                  Re: Roadster Coupe Gearbox woes..

                  Many thanks for the replies.

                  Looks like I'll be checking the wiring this weekend, then IF it happens again after that maybe drop it off to Fudgesmart, or maybe a closer MB garage who will hopefully have the Star diagnostic system!

                  Comment


                  • #10
                    Re: Roadster Coupe Gearbox woes..

                    You've also got another very good Smart specialist, Rob at S2Smarts in Watford, if Fudge is to far.

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                    • #11
                      Re: Roadster Coupe Gearbox woes..

                      You can check the wiring yourself.

                      1. Jack up the rear - put it on axle stands.
                      2. Slide underneath on your back until your eyes are level with the intercooler air scoop (a black plastic frame with a rubber strip along the bottom - unless it's snapped off).
                      3. Look straight up the scoop - you will see a black wire with plastic sheathing passing across the top of it - quite usually on the right hand side (as you look up) you will see a cut out on the side of the plastic frame where the wire passes.
                      4. Pull the wire away from the frame (it's loose) and look for evidence of cuts to the outer sheathing where it's chaffed on the frame.

                      Cuts to the outer will likely mean there's cuts to the wires themselves.
                      When the roads are wet, spray gets kicked up there, and a droplet of water will form a short across 2 of the wires in the loom and bring on the 3-bar error.

                      Eventually the wires will cut completely and the battery reset trick will no longer work.

                      Comment


                      • #12
                        Re: Roadster Coupe Gearbox woes..



                        This is what you are looking for, in the photo the harness has been removed from under the scoop for repair. With your symptoms it's 95% sure that this or corrosion/water ingress of the pictured connector is your culprit.

                        Cheers!

                        Comment


                        • #13
                          Re: Roadster Coupe Gearbox woes..

                          Great, thanks alot guys, thats sundays task sorted.

                          Just got the car back home from the garage, all good EXCEPT when luckily we were home, went to turn car around, reverse, select forward.. no gears! pushed it onto the patio no probs.

                          I did the disconnect battery thing, got it started, forward was a no go, select reverse and the rear wheels would 'pulse' backwards, with a muffled clonking sound from the rear.
                          Another thing, I've never had to apply the brake while starting the car before.. I did this time.

                          Anyway, I'll be checking the wiring tomorrow.

                          Comment


                          • #14
                            Re: Roadster Coupe Gearbox woes..

                            Replaced my intercooler scoop today,and low and behold i found that the outer sheathing on the wiring had been worn through by the scoop. Modified the new scoop before fitting and rewrapped the wiring with tape.

                            Comment


                            • #15
                              Re: Roadster Coupe Gearbox woes..

                              just had a poke around under the car, the outer sheath was worn through, but the wires underneath seemed fine.
                              Gonna try to detach the connector for some wd40 spraying, and protect the wires with a section of rubber hose where it touches the scoop.
                              Fingers crossed!
                              Last edited by europas2; 23-02-14, 05:29 PM.

                              Comment

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