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Replacing The Multiair Unit (Actuator) On An Alfa 1.4 MiTo or Giulietta

If a miss fire develops on one cylinder and it's not the spark plug or coil pack then you probably need a new multiair actuator, a good tell tell sign is an oily spark plug. The recommended oil change on these models is 18,000 miles but we feel it should be half that (9,000 miles) and don't forget to change the over looked micro filter. This 'How To' is based on the MiTo 1.4 TB Multiair 170hp.

Multiair unit 46342822, Multiair gasket 55222222
Rocker cover gasket 55233643, Micro filter 55238665
WORKSHOP TIME 2hr 11mins


You can BOOK your car in or just look for a QUOTE for this service on the 1.4 MiTo or Giulietta.

Pull off the plastic engine cover.

There's x3 mounting rubbers which tend to pull out of the cover and stick to their fixings, you need to secure them back in the cover first before you try replacing the cover on the engine.

Unclip the breather hose at both ends from the intake pipe to the rocker expansion chamber.

Undo the 10mm bolt and remove the pipe.

Undo the 10mm bolts 1-10 then unbolt 11 on the bracket.

Pull out the x4 coil packs.

Unclip the x4 connectors to the back of the multiair unit by pulling up the yellow locking clip and pressing in the release tab on the back.

Now move all the top assembly up to the right corner.

Pull back the bracket clip to release the connector on a wire to the multiair unit then unplug it the same way as the others.

Release the lambda sensor and fuel hose from the bracket....

....then undo the x2 10mm nuts.

Next is to remove the battery so you can access a bolt. MAKE SURE THE KEY IS OUT OF THE IGNITION AND AWAY FROM THE VEHICLE BEFORE YOU DISCONNECT THE BATTERY. Undo the negative terminal 10mm nut and pull off the lead, take off the plastic cover to the positive terminal and do the same.

Undo the 13mm nut to the batteries securing strap and lift out the battery.

Now to shake off the vacuum pump shield so disconnect the pumps breather hose. The bolts & nut are all 10mm so undo nut 5, bolt 4 is below the vacuum pump bolt, 3 goes through the inlet manifold pipes bracket, 2 is again below the vacuum pump bolt and just loosen bolt 1.... slide the shield enough to drop it slightly.

Undo the top 10mm bolt to the plastic cam belt cover (other models may be a 13mm).

Undo the x12 10mm bolts to the rocker cover....

...and work the cover free.

Place the locking tool on the Multiair unit, screw down the back bolts then wind in the front bolts to compress the rocker springs.

Undo the x9 T45 bolts (TORX) to the multiair unit...

....and remove the unit.

This is the important part...WATCH OUT THAT THE HYDRAULIC LIFTERS DON'T DROP OUT THE BOTTOM OF THE MULTIAIR UNIT AS YOU REMOVE IT!!! Check that all x8 of them are still in the unit, if not start searching the engine for them.

This is the Devils spawn and each lifter comes in two parts. If it's left in the head wave goodbye to valves and cam shafts.

Unclip the breather pipe and pull the crank sensor wire out from the cam belt cover.

Undo the top cam covers bottom 10mm bolt and remove the cover.

Remove the 10mm allen key micro filter.

The micro filter is another problem child and needs replacing.

Clean the surface area of the head and replace the multiair units metal gasket.

Replace the rocker cover gasket.

Once the multiair unit is bolted back in place, just before you put the rocker cover back on put a couple of blobs of silicone sealant at both ends either side of the cam shaft.

You will also need to change the oil and oil filter so next go to 'Giving The MiTo & Giulietta 1.4 Multiair Turbo An Oil & Filter Change'.

Related Links: Spark plug replacement | Changing the cam belt | Service costs

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