Freelander 1.8 headgasket

[white90]

The following thread is the replacement of the old composite head gasket/plastic locating dowels with the latest MLS head gasket, steel dowels, and shim steel head protector.

Problems with the K-series engine is well known and documented elsewhere. The steel dowels prevent the head moving in relation to the block, the MLS head gasket makes a better seal, and the shim steel head protector stops the fire rings of the head gasket from digging into head gasket face. Land Rover supply a more comprehensive head set, which includes a stronger head bolt rail, which goes in the sump - the set I am using in this thread is what you should get from a normal motor factors.

Please note that this engine is an interference engine. This means that if the timing is wrong there's a distinct possibility that the pistons will strike the valves and bend them, so take great care when setting the timing.

Your engine-

Make sure you know your radio code and then disconnect the battery. Remove the single 13mm bolt and then lift the battery out.

Several clips hold the top cover of the air filter housing in place.

Lever the special clip as shown and it will come loose

Undo the two 8mm head bolts that hold the lower part of the air filter housing to the side of the battery tray, pull off the lower pipe connection, and then lift the rest of the air filter assembly out.

Plug lead cover next - 2 x philips screws.

The plug caps are very long and can be stuck. Be careful how much force you use to remove them as they can split or break.

The distributor cap is held in place by 2 x 7mm captive bolts. Remove them, unplug the coil lead (the one in the centre of the cap), and then remove the cap/leads.

The plastic rear seal hooks off the rotor arm.

Remove the pipes that go from the head to the throttle body/inlet manifold. The spring loaded clamps can be compressed with a pair of pliers.

Unplug any sensors on the throttle body and cylinder head.

Unplug the coil.

Undo the 2 x 10mm bolts that hold the coil mounting bracket to the head and remove the assembly

The more powerful hose clamps require mole grips to remove - take the top radiator hose and bypass off.

On the rear left corner of the head, disconnect the bypass hose by the inlet manifold.

Rocker cover next. There are over 20 x 8mm bolts - all the same length. Remove them and lift the rocker off.

Note that there are some either side of the spark plug holes.

Lift off the rocker cover and gasket - you will now be able to see the camshaft assembly.

Gasket-

Timing upper cover next - there 6 bolts to remove. 5 are 8mm, and one that is right don at the bottom is 10mm and is a pinch bolt, so only needs to be undone a few turns. The cover will then lift out with a bit of fiddling and the camshaft sprockets, timing belt, and tensioner can now be seen.

The 10mm pinch bolt.

Now to set the timing. A 19mm socket on the crank bolt - turn the engine clockwise when setting the timing.

Important

Both sprockets are identical and can be accidentally fitted incorrectly either in the wrong position on the camshaft they came off, or in the wrong position on the wrong camshaft. While putting them on in the wrong positions won't damage the engine - you won't be able to start it. When you come to remove the sprockets you will see that there is a shallow 'V'-shaped slot either side of the camshaft bolt. At one end of the slot there will be the roll pin that locates the sprocket in the right position on the camshaft. Make a mark on the end of the slot where the pin is to ensure it goes back on in the right position. Also mark each sprocket with which camshaft it came off. In case you forget - on the back of each sprocket the pin location for Inlet and exhaust use is marked.

Turn the crankshaft until the cam timing marks are like this - note that the left hand sprocket (inlet) has the word 'exhaust' upside down (opposite - the word 'Inlet' is the right way up) the right hand sprocket (exhaust is the reverse). Note the slots in the edge of the sprocket - place a ruler across the centre of the camshaft bolts and through the two lines - it should all be in line.

The cam sprockets have to be removed - put a 17mm spanner on the bolt head and give it a sharp whack with a hammer. Do the same with both bolts, re-check the timing, and then remove the bolts/washers.

Using an 8mm allen key - remove the centre bolt from the belt tensioner, then undo the 8mm head bolt that holds it in the tension position.

Remove the tensioner assembly - note this is the manual type, there's also an automatic tensioner, but remove of either is the same.

With a bit of careful leverage - the sprockets can now be lifted off the cams and the belt tucked out of the way.

As previously mentioned - the pin location marks dependant on which camshaft the sprocket is fitted to.

If you want to make sure - identify each sprocket by marking it.

There's an 8mm bolt underneath each camshaft end - remove both of them, then carefully pull the rear cover away from the head (be careful not to split the cover - it only needs to clear the ends of the cams.

Inlet manifold next and all 13mm nuts. The manifold will come away from the head and rest back away from the engine - there is no need to disconnect the throttle cable, vaccuum/fuel pipes, and some sensors.

The alternator top mounting bracket now needs removing. 15mm nut/bolt to seperate the top of the alternator from the bracket - pull it towards the radiator to gain more room, then 13mm nut and 10mm bolt to remove the bracket.

Now the exhaust manifold. There are 5 x 15mm nuts holding it to the head and they are always this corroded, but in this case it works in your favour. The rusted/siezed nuts mean the the stud comes out of the head - thereby making it easier to lift the head off without having to draw it backwards when you come to remove it. If any of the studs stay in place, then you will have to remove the undershield and release the lower exhaust support in order to be able to move the manifold away from the head (it's pretty rigid otherwise)

You can remove the cams before removing the head, but by manipulating the cams, you can remove the head bolts, which are E12 Torx bolts.

Undo the head bolts in the reverse sequence as fitting them. (start at 10 and work backwards to this diagram)

The head bolts are very long - they pass right through the head and block and screw into an alloy rail in the sump.

The head will now lift off - you may have to apply some leverage to it to break the seal.

There is no pisition you can put the cams in that means all valves are in the closed position, so the camshafts and hydraulic lifters have to be removed so that the head can be skimmed (resoring the head gasket face)

There are 26 x 8mm bolts (all the same length), that holds the camshaft housing to the head - they are very prone to rounding off, so be careful when undoing them. With care, the cam housing can be lifted off with the cams still in place, although they have to be lifted out, so it isn't important.

Hydraulic tappets next. I use a magnetic pick-up tool to take them out, but you can turn the head upside down and they might fall out. Keep them in order so they go back in the same hole they came out of.

All the valves are now closed and the head is now ready to be sent off to be skimmed.

Thoroughly clean the top of the block, taking care how you do it as the block is alloy. I use a new stanley blade to do this.

The skimmed head ready to be refitted. Check for any swarf and clean it.

The new type head gasket kit.

Tap the new steel dowels into their holes in the block.

Place the head gasket on the block - making sure it's on the right way round/up

Then the shim steel head protector.

Place the head back on the block - making sure it fits on both dowels. You may have to thump it with your hand to get it to sit square. Fit new head bolts, tighten them in the sequence shown above to 20nm, then 180-deg, then a second 180-deg, going through the tightening sequence each stage. Put the hydraulic lifters back in the same holes they came out of.

New camshaft oil seals - make sure they sit square in the housing. Inlet cam at the back (the one with the rotor arm on)

There's no gasket between the camshaft housing and head - I use threadlock or similar. Put a dot of it on the face and then spread it out thinly - avoiding oilways etc, but making sure the whole contact area is coated.

Place the camshaft top half in place and tighten the bolts in a diagonal sequence from the centre outwards. There will be some resistance at some of the cam lobes will press valves open. Re-attach the rear cover with the 2 x 8mm bolts, then

replace the cam sprockets taking care that they go back on the same camshaft and in the same position. Replace the bolts and hand tighten them. Rotate the cams until the timing marks are in the correct position and once again check with a straight edge.

Place a new rubber gasket on the inlet manifold and bolt it back on.

Dribble some fresh oil over the cam lobes to pre-lubricate the lifters and then place a new rocker gasket the correct way up/round (not that you're likely to get it wrong with all that writing on it)

Then replace the rocker cover.

Reattach the timing belt making sure there is no slack on the alternator side (be careful not to turn the crankshaft while fitting the belt). Tension it - there's no tension figure for this - the belt only has to have light finger pressure on it. Then tighten the camshaft bolts. Put the rest of the engine back together.

The exhaust manifold studs are very awkward to put back in - the manifold does move a small amount, so you need to manipulate it to get the studs back in. Take care when doing this as you could strip the threads in the head.

Rotate the crankshaft 2 complete turns and re-check the timing marks. fill the cooling system and bleed it. There's a bleed valve on the heater hose and one on the pipe to the bottom radiator hose behind the distributor (access to it is from under the rear of the air filter housing). Start the engine (it's usual for it to take a few goes to get it to start due to water residue in the cylinders. Turn the windscreen heater on and check to make sure the air is coming out hot after a while. If not, bleed the system again. Run the engine up to temperature and keep an eye on the temperature guage and bleed the sytem occasionally to make sure all air is expelled.

There really is a bleed screw down there!

If you accidentally turn the crankshaft while replacing the timing belt you will have to remove the drivers wheel, plastic engine protector, crankshaft pulley, and lower timing cover, so be careful.

Timing information is the Freelander timing belt change in the tech archive - http://forums.lr4x4.com/index.php?showtopic=9652

Les.