Page 1 of 4 123 ... LastLast
Results 1 to 10 of 39

Thread: Replacing timing chain/rails/sprockets without taking head off?

  1. #1
    Join Date
    Sep 2013
    Location
    Windsor, Berkshire
    Posts
    117

    Replacing timing chain/rails/sprockets without taking head off?

    Hiya,

    I mentioned it in my general engine rebuild thread but the more I research and the more I ask Smart Indies the more confused I get.

    My latest bit of info comes from Smart-TECNIC in Birmingham who, while being 2 hours away, offered to do the job for half of the previous quote which brings it into an area where I start to balance the learning benefit and DIY satisfaction against the convenience of just getting it done.

    They do however state that they will do the job without removing the head and having seen the guides for rebuilding 600cc engines, that strikes me as impossible and they do the same job on those engines for even less.

    Can anyone enlighten me? If this is indeed possible it may well mean that the DIY job could also be much easier.

    Thanks!
    Past:
    City Coupe Passion 1999 LHD, Fortwo CDI 2002 LHD, Fortwo 2003 RHD. :
    Present:
    Smart Roadster Convertible 2005 1.1 Passion 2006,

  2. #2
    Join Date
    Nov 2007
    Location
    BANCHORY
    Posts
    3,348
    Can be done without removing head. Rocker cover got to come off to get access to the two bolts that hold timing cover at top. Engine must be lowered sufficiently to provide access to pull pin for timing chain tensioner.
    Drives a Smart Cdi - 65 to 85 MPG

  3. #3
    Join Date
    Sep 2013
    Location
    Windsor, Berkshire
    Posts
    117
    Thanks!

    Is there a guide somewhere, aimed at just doing this on 700ccm and not getting the entire engine out and rebuilt?
    Past:
    City Coupe Passion 1999 LHD, Fortwo CDI 2002 LHD, Fortwo 2003 RHD. :
    Present:
    Smart Roadster Convertible 2005 1.1 Passion 2006,

  4. #4
    Join Date
    Jan 2013
    Location
    Swindon england
    Posts
    84
    the only drama is the rail, its held in by a metal dowel pin (in the head) i couldnt have changed mine without the head being off, then i had to take it to an engineering firm, it needed a slide hammer. you may get away with keeping your old rail and just replacing the chain and sprockets
    Last edited by jonneyflame; 24-10-2013 at 04:28 PM.

  5. #5
    Join Date
    Sep 2013
    Location
    Windsor, Berkshire
    Posts
    117
    Nope, since I assume the current rattling comes from a broken rail. Could be the tensioner but my bet is the rail like on so many other Smart engines.
    Last edited by sneakinhysteria; 24-10-2013 at 04:58 PM.
    Past:
    City Coupe Passion 1999 LHD, Fortwo CDI 2002 LHD, Fortwo 2003 RHD. :
    Present:
    Smart Roadster Convertible 2005 1.1 Passion 2006,

  6. #6
    Join Date
    Jan 2009
    Location
    Norway
    Posts
    2,657
    Does anyone else ever think it would be good to have a spare, rebuilt engine, in a box in the attic?
    Anytime there's a problem, fit the "new" one, then fix the "old" one....rotational recycling!

  7. #7
    Join Date
    Jan 2013
    Location
    Swindon england
    Posts
    84
    sometimes the tensioner will go, slackening the chain causing a rattle, you might be lucky

  8. #8
    Join Date
    Nov 2007
    Location
    BANCHORY
    Posts
    3,348
    The guides for this operation at FQ101 are second to none.

    Pulling the pin ought to be fairly easy. I suggest using a suitably long M6 threaded bar (assuming the pin is threaded M6 - need to be confirmed!), long socket as yoke, a couple of nuts an a stack of 6 mm ID penny washers. Clean the threads in head of pin, then screw the threaded bar home by making the two nuts tight at other end and turning bar with outermost nut.
    Remove the nuts and fit a sufficiently large diameter long socket or pipe over the threaded bar followed by the stack of penny washers and nut.
    Tightening the nut should pull pin out. Can't see any need for heat but may be required to get pin moving.
    Drives a Smart Cdi - 65 to 85 MPG

  9. #9
    Join Date
    Sep 2013
    Location
    Windsor, Berkshire
    Posts
    117
    Thanks Olsen,

    Here is my issue, I kept studying the 600ccm rebuild guide on FQ101 and their tensioner replacement guide (sic, that white/black part is one of the two rails rail, not the hydraulic tensioner!?) and I struggle to put the two together. I expect the timing case to come off but it's not. And these are supposed to be the same 600ccm engine.

    I have to add that I never worked directly on the inside of an engine before (but on pretty much all other parts of a car) and while you may say: then don't do it, I want to start somewhere so I'm no longer an engine virgin.
    Past:
    City Coupe Passion 1999 LHD, Fortwo CDI 2002 LHD, Fortwo 2003 RHD. :
    Present:
    Smart Roadster Convertible 2005 1.1 Passion 2006,

  10. #10
    Join Date
    Mar 2012
    Location
    Daventry
    Posts
    636
    There's no doubt that you can replace the chain, sprockets and tensioner without removing the head - the black and cream plastic guide that's pushed by the tensioner seems to be pretty reliable and you probably wouldn't need to swap that and avoid the problem of removing the pin. The black plastic guide is more susceptible to shattering and could be troublesome to replace with the head in situ as it hooks over a cross pin in the head but is mounted on a fixed pin at its lower end. If the black one has broken up, you'd be well advised to do a full rebuild - I did one earlier this year and there were fragments of black plastic almost completely clogging the oil pickup pipe strainer and smaller bits trapped in the oil fiter!!

    You will encounter another problem when refitting the timing cover as it's a tight fit up against the head when located on its dowels - there's a strong possibility that you'll dislodge the lower lamination of the head gasket - done it myself twice now!

    I have a work-around for this which has been ok on my daily runaround - cut and remove the lower lamination (0.1mm thick) which gives the space to re-fit the cover and seal it to the remaining layers of head gasket with Dirko.

    Hope that all makes sense!



    Lower layer of head gasket
    Last edited by bob-in-dav; 24-10-2013 at 08:31 PM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •