BA-BF Falcon 6 Cylinder Spark Plug Replacement
Today we are taking a look at replacing the spark plugs on BA and BF model Falcon’s equipped with the six cylinder engine.
These engines are fitted with Platinum or Iridium tipped spark plugs meaning that replacement is due only after 150,000km and equivalent replacements only should be used (there is a bunch of genuine and non-genuine BA-BF Spark Plugs and Coils available on Ebay).
The first step is to remove the upper part of the air filter housing and the air intake to the throttle body. There are four clips joining the top and bottom sections of the air filter housing.
The rest of the air intake is secured to the inlet manifold with two 10mm bolts and there is also a hose to the tappet cover that has to be taken off.
Once the bolts and the hose are removed it is simply a matter of pulling the air intake away from the throttle body and placing the complete unit out of the way. It is a good idea to stuff a clean rag into the throat of the throttle body to prevent any foreign objects entering.
The next step is to remove the top cover plate. There are eight 5mm allen key bolts securing it to the tappet cover. These bolts have a small fibre washer that often falls off when the bolts are removed.
As well as the allen key bolts you will have to temporarily remove the oil filler cap and carefully remove the PCV valve from the tappet cover. You might find it easier to remove the hose from the PCV valve first and then gently ‘rock’ the valve backwards and forwards while lifting it up to remove it.
Once we have that done we can remove the top engine cover.
At this stage it is a good idea to refit the oil filler cap and block the PCV valve hole with a clean rag. Better to be safe than sorry!
Now we have to remove the ignition coils to gain access to the spark plugs. You can move the coils out of the way enough with the wiring still connected, just be careful not to place too much pressure on the wires though.
It is a good idea to make a mental note of where the coils sit in relation to the tapper cover surface so when refitting them you know that they are all the way home.
To remove the coils we need to twist them while pulling upwards.
Lay each coil near it’s corresponding cylinder. If you have access to compressed air blow out any grit or foreign objects in the spark plug tubes. A small length of garden hose and a lung-full of air can be substituted if compressed air is not available.
Grab your 5/8 Spark Plug socket, extension bar and ratchet. When loosening the spark plugs be sure to use two hands on the ratchet to keep the extension bar and socket straight in the spark plug hole.
If any of the spark plugs are tight to a point where you struggle to undo them, STOP and have a mechanic do the job for you. You don’t want to have to remove the cylinder head just because of a broken spark plug!
If the rubber in your socket that grips the spark plug is worn out as mine is you can either use a magnetic probe to get the spark plugs out…
Or a length of suitably sized hose…
Once you have all six plugs out refitting is the reverse of these steps with attention to the following points -
- Be sure to visually check the spark plug gap of the new plugs before fitting. They should be gapped right out of the box but they can get dropped etc etc. Use your socket, magnetic probe or piece of hose to lower the new plugs into position.
- A smear of engine oil or an anti-seize compound on the threads of the new plugs will ensure that they are easily removed next time.
- Be sure to check that the coils are seated correctly on the spark plugs and have all gone down to their original sitting position.
- Be sure to remove any pieces of rag you have used to cover the throttle body etc!
- Fitting the air intake to the throttle body can be a bit troublesome and may require a bit of twisting and turning of the air intake before you get it seated all the way around the throttle body housing. Persistence is the key here!