Today I have decided to put together a long overdue update for our Falcon Head Gasket Replacement Tutorial. Before we get into the nuts and bolts of it (pun intended) I want to stress that it is vitally important to get a proper diagnosis before deciding to tear the head off your engine, it’s a major job and you don’t want to find out afterwards that you went to all that trouble and expense for nothing! Also please read through this article in it’s entirety before starting out (including Part Two) so that you get an understanding of the steps involved and to ensure you have, or have access to, the required tools and equipment needed.
And speaking of expense, with an alloy head you can’t simply take the head off, replace the gasket and fit it all back up again. The head must, at the very least, BE CHECKED TO SEE IF IT’S STRAIGHT and with the Falcon engine (and quite a few others for that matter) the head bolts MUST BE REPLACED as they are a torque-to-yield design. It is also highly recommended that you USE A GENUINE FORD AU MODEL HEAD GASKET as these are a metal shim type gasket (rather than the usual graphite) and will last a lot longer. You will more than likely find that buying a complete VRS kit (Valve Regrind Set) for your model from Repco, Bursons or Supercheap is the cheapest way to buy the rest of the gaskets that you will need.
So yes, you might spend a few more dollars than you would if you cut corners, but don’t be cheap because it will come back and bite you, do it once and do it right! Ok I think I’m done with the lectures, let’s get into it.
The first step is to remove the bottom radiator hose at the radiator end and drain the cooling system.
Next up is disconnect the battery (make sure you have any radio security codes you need).
Now remove the air intake from the top of the radiator shroud (two wingnut type bolts) and remove the top of the air filter box with it and remove the air filter.
The top radiator hose and expansion tank hose can now be removed.
Some people remove the fan, fan shroud and radiator at this point. I usually don’t unless the radiator is getting renewed or cleaned, but removing it does give you more room. Please yourself and if you’re not sure how to remove it there is instructions in the Falcon Timing Chain article.
Removing the tappet cover is next on the list.
Start by numbering the spark plug leads to their corresponding cylinders using a permanent marker, this saves a lot of confusion later if they get mixed up. To remove the leads from the spark plugs use a twisting and pulling motion, rather than just trying to yank them straight off. Take the leads out of the plastic separators on the tappet cover and lay them over the intake side of the engine. The brake booster hose need to be removed also, compress and slide the clamp down the hose a bit and then twist it off the fitting.
The next step is to get the accelerator/cruise control cables out of the way. To do this you need to remove the plastic 17mm nut from the thread on the accelerator cable and slide the inner of the cable out through the cut-out.
Next twist the cable at an angle to remove it from the ball on the throttle linkage.
And then remove the clip off the end of the cable before loosing it!
Removing the cruise control cable (if fitted) if pretty much self explanatory. Then we can remove the hose to the PCV valve at the front of the tappet cover, and remove the breather hose at the rear.
Then we can remove the four 13mm nuts that hold the tappet cover on, you will have to use a spanner on the back one. Be sure to remove the seals as well before lifting the cover off. The bracket on the back one for the brake booster vacuum hose can stay attached to the hose and not get in the way too much.
The tappet cover might take a little bit off persuasion to get moving (tapping on the side with a soft hammer is better than levering between it and cylinder head) and it will take a bit of maneuvering to get it over the back stud and out of the way. Take it easy, lift the front up first and try different angles and you will win!
Now we can start unbolting the manifolds. I suggest starting with the intake as it has the hardest bolts to get to. There is a bit of variance in intake manifold’s between the different models but our ED should give you an idea of what needs to happen. Start by removing the two temp sensor connectors.
Then unbolt the engine lifting hook.
And then the bottom housing bolt.
Now for the fun part! There are six 10mm bolts that secure the bottom of the intake manifold to the head. These can be a bugger to get to but over the years I have found the best way to get to them is to use a 1/4 inch drive ratchet with two extension bars, a universal joint and then the socket. I’m sure some people will disagree with me but this is by far my preferred method.
With a bit of persistence all of the bottom inlet manifold bolts can be removed this way.
Once you have conquered the bottom bolts it’s all downhill from there, well mostly! There should be five bolts left along the top of the intake manifold that need to come out and there is also a bracket underneath that needs to be unbolted before the manifold will move. A 10mm spanner is needed to remove the bolt.
With all of those bolts removed the manifold should be able to move slightly away from the cylinder head.
Now we can move over to the exhaust manifold. Our ED has extractors fitted so it might look a bit different, typically there is a large heat shield that needs to be removed before you get access to the twelve 13mm manifold to head bolts.
Once again we just want to remove the bolts and move the manifold away from the head enough so we can lift the head past it.
Next is moving the power steering pump out of the way. We start by removing the belt, loosen the 24mm nut (a 15/16 spanner/socket will fit also) and then rotate the tensioner anti-clockwise with a 13mm spanner to loosen and remove the belt.
Then remove the two 13mm bolts at the front of the pump and the 17mm nut at the rear.
The pump can now be moved over and out of the way. The pump bracket now needs to be removed – two 13mm bolts.
Next on the list is setting the engine up on Top Dead Centre (TDC), firing on no.1 cylinder. To do this we rotate the engine clockwise until the mark on the harmonic balancer lines up with the TDC mark on the timing cover and check that the camshaft timing mark is just above the top of the cylinder head on the passengers side. If the camshaft mark is on the drivers side of the head (engine firing on no.6) rotate the crankshaft another full turn and it should be lined up. NOTE – if you have a timing chain with two yellow links in it see THIS ARTICLE for the correct timing info.
The standard camshaft sprocket will be slightly different to this one but this should give you an idea of where the mark should be.
The next step is to zip-tie the timing chain to the camshaft sprocket so that we can remove the sprocket from the camshaft without loosing the chain and screwing up the valve timing.
Now we can ‘crack’ the camshaft sprocket bolt, i.e. place a 1/2 inch drive socket (16mm on this engine but I believe the factory bolt is 17mm) and ratchet on the bolt and give the ratchet a sharp hit, enough to loosen the bolt but limit the amount the engine rotates. Don’t remove the bolt at this stage, just make sure it’s loose and the timing marks aren’t too far out of whack.
The next step is to release the timing chain tensioner. See THIS ARTICLE for step by step instructions.
The top timing chain guide bolt can be removed now also. This is a 10mm bolt and it’s often very tight so I suggest using a single hex (six point) socket only.
Up next we can remove the camshaft sprocket bolt and washer. Be very careful not to drop them down the timing cover! Then we can gently lever the sprocket off the camshaft and let it sit between the two chain guides. Providing nothing is majorly disturbed, the valve timing should be correct for when it comes time for reassembly.
Finally, we are almost ready to lift the head off! At this point some people recommend removing the valve gear and camshaft (series of 10mm bolts) however I highly recommend not doing this because the head bolts are usually very tight and it’s very easy to round the head’s off if you are not careful. Having the valve gear in place actually forces the socket to stay straight up and down on the head bolt, which helps to limit bolt-head damage and leaving the valve gear on eliminates the chance of losing one of the lash adjusters in the rocker arms. When you see the socket in place I’m sure it will all make sense! The only trade-off is that the CYLINDER HEAD MUST BE LAID ON IT’S SIDE AT ALL TIMES UNTIL THE CAMSHAFT AND VALVE GEAR IS REMOVED. Here is why, with the camshaft still in place the valves protrude past the face of the head and can be damaged easily.
The head bolts are 14mm and they need a good single hex (six point) 1/2 inch drive socket, small extension and breaker bar to remove. You might find that an extension to the breaker bar helps also. The most important thing to remember here is to use one hand to do the grunt work and the other to keep the socket nice and straight on the head of the bolt.
Although not vitally important, I do recommend unbolting the head in a sequence starting with the middle bolts and working you’re way out. Once you have all of them loose completely remove them so they won’t get in the way when we lift the head off.
A WORD OF CAUTION HERE – DO NOT attempt to lift the head off yourself for two reasons. The first one is that they are heavier and more cumbersome than they look and the second reason is that it has to come up evenly off the block or you risk snapping the top timing chain guide, which is a not a fun thing to replace. Definitely get some help for this next step.
With all of the head bolts removed you should be able to carefully lift the head a little bit each end at a time to ensure that it’s not stuck anywhere. If you find that you can’t dislodge it don’t be tempted to lever between it and the block, there is a good chance of doing damage this way, get a soft hammer (rubber) and tap around the top edge of the head until you feel it move a little.
Have one last look to make sure that everything is removed/disconnected, grab your helper and lift the head evenly until it clears the timing chain sprocket and guide and then move it to your bench or wherever you are going to put it and LAY IT ON IT’S SIDE.
Well done! Before anything else I now like to make sure that the two locating dowels are present and accounted for. This time we had one in the block and one in the head so I gently worked them both out with multi-grips and put them with the rest of the bits and pieces. Be careful not to squash them with multi’s!
Now we can start having a look around for evidence that might give us a hint as to what’s gone wrong. Our ED looked like it had more water than oil in the sump and if you take a look at the head you will see that cylinders 2 and 4 have had their fair share of coolant in them, in fact the cleaning action of the water has softened a lot of the carbon build up so I’d say this has been going on for a little while.
There might not always be evidence of what went wrong, which is why it’s important to get the head checked out, but for our ED there must be something fairly major going on, it certainly doesn’t look like a typical warped head/blown gasket situation and after examining number 2 and 4 combustion chambers the cause is found – one crack in each between the coolant passage and the chamber.
This has kind of thrown a spanner in the works (pun intended again) as this head is basically junk now, the coolant passages have had corrosion in them and have been welded up previously so it’s not a good candidate for a repair so I’m not sure which way we’ll go yet.
Depending on who you get to check the head out they may ask you to remove the valve gear and camshaft before bringing it in. If this is the case set the head up with a block of wood under one end (so the protruding valves don’t get damaged) and undo the series of 10mm bolts, starting from the middle and working you’re way out. Don’t completely remove the bolts, just make sure they are wound all the way out of their threads, or the assembly can come apart! Also take care not to lose any of the lash adjusters that are found in the end of the rocker arms. A couple are likely to fall out, just note where they have fallen and refit them once you can turn the assembly over so they don’t fall out again.
Falcon Lash Adjuster Components – NOTE: not all adjusters come apart and not all have a shim fitted (red arrow).
Before calling it a day it’s important to inspect the block. Typically the block won’t see the sort of damage that the cylinder head does but it’s always worth a thorough look. Soak up any coolant in the cylinders with rags and then wipe down the block face with a rag. From here it’s a good idea to run your eye over the block carefully, looking for any corroded water jackets or other nasties. As you can see in the pic below the water jackets in our ED block are not perfect and look like they have suffered from a lack of coolant (or a poor quality coolant) and if this was any worse I’d be hesitant to go any further with this engine. Just something to keep an eye out for as you look over your own engine.
If you’re satisfied that the block is in good shape get yourself some single-sided razor blades, some rags to stuff into the cylinders and coolant/oil passages and start the lovely job of getting rid of all of the old gasket. This can be a tedious job at best but it’s vitally important that the block be a clean and free from old gasket as possible. After a going over with the razor blade I like to give it a rub over with some emery tape and then clean it off with a petrol (or solvent) soaked rag. The images below shows the front of the block after I’ve cleaned it compared to the rest that hasn’t been touched.
We also need to soak up any oil or coolant that has found it’s way into the head bolt holes, if you have an air compressor I suggest holding a rag over the hole and giving it a squirt with an air blower. This is also very important as any remaining oil or coolant can seep up the threads as you’re tightening the bolts which will cause the gasket not to seal, or even stop the bolt from turning giving a false torque wrench reading or even worse, split the block.
I recommend against cleaning the tops of the pistons, in my mind cleaning the carbon off offers little advantage and if a large enough piece was to become lodges between the piston and the bore it could cause problems for the bore, piston or rings.
Once the block is cleaned and inspected I suggest giving it a generous spray of WD-40 or something similar to stop any surface rust forming and cover it over with a cloth to keep any crud out.
The reassembly is covered in FALCON 4.0 HEAD GASKET REPLACEMENT -PART TWO