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.
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!
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great as easy as you told it
Good to hear!
Regards,
Craig
Hi Craig,
all seemed ok till i could not get the socket and extension shaft into the rear spark plug tube. it would not fit between the bonnet and tube. any ideas
regards,
Peter
Craig,
As a printer I’m a shithouse mechanic so your article is helpful as. You probabaly saved me a stack of money.
Jim
Hi Jim,
Your comment cracked me up! Good to hear the spark plug article came in handy for you.
Regards,
Craig
Hi Craig,
Glad to hear that Jim’s comment cracked you up, but it doesn’t help me to get at the rearmost spark plug. I have a 150 mm extension on the spark plug socket spanner which is just right to reach five of the spark plugs, but the car body overhangs the rearmost plug hole.
So how did you do it? Please don’t tell me to remove the head first. It seems to me that you need a torsion bar with a universal joint in the middle. I’m going to Autobarn right now and see whether they have one, but I suspect Ford have made a special tool for the job.
Regards – Emil
Hi Craig and Peter,
I did go to Autobarn and the solution is simple beyond belief, but it will bring tears to your eyes. As I suspected, there is a special purpose tool consisting of a long T-bar handle with a 16 mm socket at the end that is 125 mm long with a swivel at the handle end. And the cost? $115 (I warned you).
All this cost and bother just to chcange one spark plug! Now, why couldn’t they obstruct all 6 spark plugs in a similar way? Then I would be happy to pay the $115, in fact it would be a bargain at $19.17 per plug.
The spark plug cover also has a screw at the back that is even more inaccessible, but don’t get me started on that!
Regards – Emil
Hi Emil,
They certainly don’t make em like they used to do they! From memory, and not a good memory at that, I think we use two small extensions and drop the spark plug socket down first and then fit the extensions and ratchet.
I can see how the tool you bought would be a simpler solution – albeit a very expensive one.
Take care,
Craig
What should the gap be for BA 6 cylinder 2002? The auto store gave me 1mm
Hi Ben,
The tune-up manual we have here lists the spark plug gap for a 2002 BA 4.0 as 1.4mm. If it’s running the factory lpg setup or turbo the gap should be reduced to 1.1mm.
Regards,
Craig
Hi, is gap for 2004 petrol BA same as 2002? I assume that it would be but you know the trouble with assumptions!
I got a tool from auto one that is the same as the one listed above for under $20……..I will let you know how good it is but on visual inspection seems ok.
Thanks
Tony
Hi Tony,
Yeah, assumptions are dangerous things aren’t they! However, from my tune-up manual it looks like all BA’s regardless of year model run a 1.4mm spark plug gap. Unless it’s running lpg which runs a slightly smaller gap at 1.1mm.
Hope that helps!
Regards,
Craig
Hi Craig,
Great guide, had a first timer like me knock this over in less than an hour.
For anyone who has trouble with the plug closest to the firewall, I used two extensions, one 75mm and one a touch shorter, with a little play it worked fine.
Cheers.