The spark plugs on a Ferrari 360 are supposed to be changed every 30,000km or 18,750 miles. I prefer to change them a little more frequently than that as I know of an example where a failed spark plug caused a misfire and cat over heating problem.
Early cars were shipped from the factory with NGK PMR8A spark plugs whereas later cars were shipped with NGK PMR8B plugs. The difference is that only the anode on the PMR8A plugs is made from platinum – the PMR8B has platinum on both the anode and cathode. The cost difference between the two types is minimal so I opt to fit PMR8B plugs regardless of the year of manufacture.
Changing the plugs is very easy and can be done by leaning in from the top of the engine bay. You may want to use a step and a wing cover to make things easier. I prefer to change one plug at a time in order to prevent any mistakes when connecting things back up.
First of all you need to remove the pencil coil. Unclip the electrical connector marked A and remove both 10mm bolts marked B.
Now withdraw the coil from the cam cover – it will pull right off.
You will need a 10mm spark plug socket – the 10mm refers to the thread diameter if you were wondering. You will also need a socket extension bar. I prefer to use the type that locks onto the socket and needs a button to the pressed to release. That way you don’t encounter any problems removing the socket once the new plug has been fitted.
Remove the old plug and check the tip for any tell tale signs of a problem.
The new plugs should be supplied gapped to the correct width but it is good practise to check – the factory setting is 0.6mm.
Now all that is left is to fit the new spark plug (torque up to 9.8Nm) and replace the coil.