Original Powertrain Teardown

The very first thing you'll notice is that there are a whole bunch of incompatibilities between the C526 gearbox and the C514 you want to fit. But it's not only on the gearbox, the engine itself poses a few issues too, although very few:

The "manicat" on the Seicento MPI will NOT clear the 1242cc block. It's a very tight fit, both above and below the block. Overhead, it will bang against the slam bar with the new engine which has it's block made taller by about an inch, thus raising the head. On the lower side, it will rub on the sump and twist the flexi pipe.

You'll need to cut it right after the cat, and weld the pipe on a downward slope then straighten it onto the flexi pipe. It needs to exit about an inch lower.

Then, the C514 gearbox is so very different. If you're doing the gearbox swap, the very first step is to loosen the big nuts on the front wheel hubs. The whole transmission shafts need to be replaced too. If you're not doing this then just pull them aside when you need them out of the way.


Loosen that big nut before removing the wheels.

At this point, raise the car and support it on jack stands.
Then undo the two bolts holding the shock absorber to the hub. You can then pull the transmissions out from the gearbox and remove them or pull them aside.


Start undoing all the ancillaries on the engine.

  • First, disconnect the battery
  • Remove the airbox (one spring and two bolts).
  • Then undo all the pipes on the intake manifold.You'll need to purge the pressure on the fuel rail before. Just use a screwdriver inside the Schrader valve on the left side of the rail. Be careful not to break the small tabs on the pipe connector.
  • Then, remove the injector wiring, spark plug cables, etc.
  • You'll notice it's still attached to the oil pressure switch.
  • Undo the top cambelt cover and remove the oil pressure switch wire.
  • Remove the piping right behind the intake manifold. You'll need to break the clip (buy new ones).
  • Undo the two bolts that hold the water temp sensor assembly. Pull it downward to separate it from the manifold and remove the pipe. You'll need the extra clearance.
  • Undo the 6 nuts holding the manifold in place, and pull it out of the engine.
  • Undo the wiring on the alternator and starter motor. You may leave them in place. Move the wires away.
  • Undo the knock sensor from the engine block.


Now onto the front side:

  • Remove the bumper from the car.
  • Undo the radiator and piping. Collect the coolant for reuse or dispose of it properly.
  • Undo the the bolt that holds the exhaust manifold to the engine, below the sump.
  • Undo the flexi-pipe clip bolt.
  • Undo the heatshield bolts above and on front of the manicat.
  • Undo the 8 bolts holding the manifold to the head.
  • Disconnect lambda sensors.
  • Carefully remove the manifold, and modify it as needed (see top of page).
  • Collect the exhaust gaskets. Replace them if damaged/worn.
  • Remove the remaining coolant piping from the engine.


Now onto the gearbox:

  • Disconnect the actuator cables from the gearbox (if this is a C526, one will be held by a clip).
  • Pull the two clips holding the cables to their brackets. Save these clips.
  • Remove all the wiring (main engine ground, VSS sensor, reverse sensor).
  • Undo and remove the clutch cable (this will need to be replaced in case of swap).


More pictures from the process. You'll notice several things when you fit the new engine, such as the block being about an inch taller. You'll know this by looking at the side of the water pump, which has a raised "block" of iron on the 1.2 block compared to the 1.1.

This is the 1.1:

All should now be ready for removal.

Next page: Engine Removal and Disassembly
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