Need to change or replace the spark plugs on your Ford Laser KN or KQ with a 1.6L four cylinder engine? Here’s how we did it! We would suggest doing this on a cold engine so that a) you don’t burn yourself accidentally and b) you aren’t putting cold spark plugs into a hot head and having issues following tightening them due to the heat expansion of the head. Haven’t got plugs yet? Find out which ones to use here.
The spark plugs are located at the top of the motor:
This 1.6L ZM engine has two coil-on-plug plugs and two short spark plug leads running to the other two; you can see the leads in blue and white here:
Starting on the left hand side as you look at the engine, grab the spark plug cap by the boot – not the wire – and pull upwards to remove the plug cap:
Inspect the bottom and sides for cracks and the presence of oil. Oil down here generally means that the rocker cover gasket is leaking around the top of the spark plug wells and cracks can mean that the spark earths out to the side of the spark plug well rather than reaching the plug, which would appear as a misfire.
These have a little bit of oil down the bottom – probably a little bit of leftover from the oil that came down into the well from the recent rocker cover gasket leak. You should be able to look down into the well to see the top of the spark plug now:
The next spark plug along is one of the coil-on-plug setups and you need to remove the coil to access it. It’s held in by two bolts with 10mm heads – remove them with a socket:
Bolt removed:
Grab the plug and lift:
Removed:
The process is repeated for the next two along – one plug wire, one coil on plug. Now you are left with nothing over the spark plugs:
Now for the removal of the spark plugs. You’ll need a socket extension and a 5/8″ or 16mm deep socket:
We’re using a Kincrome 1/2″ drive breaker bar, a 12″ extension and a 5/8″ spark plug socket. Why a breaker bar and not a ratchet wrench for this task? When installing these sorts of spark plugs you hand tighten and then use a bar to tighten by 1/2 to 2/3 of a turn further – with a non-ratcheting bar it’s easy to keep track of how far around you have gone! Loosen the plug. Once it is sitting in the plug well if you have a spark plug socket with either a magnet or rubber insert, just lift and the plug should come away. For everyone else, gently re-insert the plug cap and hook it onto the plug to withdraw it easily:
Take note of which plug came from which hole. Now is a good time to take a look at each spark plug and verify that they all look the same and aren’t covered in carbon or otherwise damaged in a way which would indicate a problem in the engine (running rich etc.).
Next: Which spark plugs to use? Alternately, jump straight to installing a new set of plugs.