New set of sparkplugs (type: see car manual, NGK BKR6EKC)
- T40 TORX socket bit or screwdriver.
- Spark plug wrench or socket for plugs, size approx 16 mm
- 3mm Allen key
- 5mm Allen key
The socket for the plugs needs to be long and thin, otherwise you will not be able to reach the plugs. My wrench has an outside diameter of approx 21 mm, and length of approx 29 cm
- Remove the six T40 Torx bolts that retain the aluminium engine top cover.
- Unscrew the oil filler cap revealing two small flush screws one either side of the filler. Remove these with your 3mm Allen key.
- Temporarily replace the oil cap.
- Unscrew bolts holding ignition coils in place (1 or 2 bolts per coil depending on the revision of the engine) using the 5mm Allen key taking care with the plastic covered leads as these will be brittle.
- Pull out the coils
- Make sure there is no dirt in the holes where the sparkplugs are, if necessary, use compressed air to blow clean or use a vacuum cleaner to suck out any debris that may have accumulated in the plug wells.
- Unscrew the old sparkplug. Tip: When the plug is unscrewed, you can use the coil with rubber attachment to withdraw the old sparkplug.
- Put the new sparkplug in the rubber piece of the coil and insert new plug one or 2 turns into engine.
- Withdraw coil and use pipewrench to screw in the new plug. Tighten down well, but don¹t exert too much force.
Repeat steps for the remaining three plugs.
- Here you can see the difference between an old (top) and new (bottom) plug.
Re-insert all the coils, and screw down with the bolts. Be very carefull not to exert too much force here, as the bolts are directly tapped into the aluminium head, and it is easy to damage to thread.
- Fix the coverplate in place again. Don’t forget to first check if the rubber O-ring around the fillercap opening is in place.
- The bolts to hold down the coverplate should not be over-tightened unless you want to crack the cover! The Fiat recommendation is 7.8Nm but there is anecdotal evidence that it is safer to do an initial tighten to 4Nm and then finish at 6Nm.
- Check it starts.
This technical guide was originally held at http://www.fiatbarchetta.com/btech/plugs/plugs.html. It was copied to this site in 2021 to ensure its availability and to reformat it into a more modern layout. The original guide was written by