Step by step guide on how to replace a cylinder head.
Estimated time: up to a full day Difficulty: Hard
Replacing a cylinder head is a massive job and is probably best carried out by a professional. But if you insist on changing this part yourself then follow the following instructions:
It is best if you write down on a list which part comes off when, so that it makes it much easier to put them back on in the right order, saving you on time later on. Do this as you go along. Label each of the wires and cables as you go along too.
Put the vehicle up on ramps and then remove the battery. Once the battery is removed you must put the engine at top dead centre on number one cylinder, as you will be removing the timing belt. You will have to carry this out manually by moving the crankshaft pulley until the engine is in the right position. There are marks located around the engine to show that it’s in position.
Next you must drain the coolant from the system. You will need a container to gather the coolant. Disconnect the hose by unscrewing the hose clip and pulling the hose from the radiator. Let the fluid drain fully from the system.
Take off the air intake duct from the air cleaner. Unscrew the screw clamp, loosen off and remove the hose. Disconnect any other screws and remove the duct. Remove any wires connected, and this would be a good time to start labelling any wires to remind you which wire goes where.
You want to remove the alternator belt now. Place a breaker bar on the tensioner and pull, relieving the tension and remove the belt.
Remove the alternator by removing the bolts on the bracket. Remove the bracket and then take the bolts off the power steering reservoir to remove this part. You will also need to disconnect the hoses from the reservoir to get it out. You will need a container to drain the fluid into. Now you can remove the three electrical connections off the alternator by prizing them off with a screwdriver. Remove the bolts holding the alternator onto the engine and turn the alternator slightly to get it out.
Remove the tensioner by removing the bolt and pulling the tensioner out.
Disconnect the oxygen sensor by separating the connectors in order to pull the cable out of the way.
Jack up the oil sump as you will need to take out the motor mount to get the timing covers out of the way. There will be a dampener needing removed before you can access the motor mount. It will have two bolts which need to be removed. Once the dampener is removed you will have to remove the bolts on the motor mount to uninstall this part.
Next is the crankshaft pulley, which has a nut in the middle which needs to be removed. The pulley should now slide off. With this out of the way we can focus on the timing cover which is held on by two nuts. Disconnect these and remove the cover.
The throttle cable now needs removed. You will need a pair of pliers to squeeze the tabs on the cable and pull it along the pulley to release the cable. Disconnect the PCV line and completely move it out the way. This plastic cable should just pull straight out.
Remove the power brake booster hose. You will need a pair of pliers to squeeze the clip and release this from the hose. You might need a flat screwdriver or something similar to prize the hose off.
Remove the two vacuum lines to get these out the way. Remember to label these so you know where they came from. I hope you remembering to label the parts you are removing, to remind you where they came from and where they go.
Disconnect the grey and black connections from the shock tower and move these out the way. Remove the crank sensor by pressing a little button and pull out the connector. Now you will need to remove the nut which is holding the dipstick tube to the cylinder head, and pull the dipstick tube away from the head.
There are four 6mm bolts holding the coil to the bracket, remove these bolts to release the coil. Remove the heater hose from the radiator and the back hose from the cylinder head to the heater core. They will likely have clips on which you will need to unscrew.
The head pipe from the exhaust manifold is held on by two 14mm nuts which you will need to remove. Disconnect the connectors for the temperature sensors and the bolt that holds on the bracket for the heater hose.
If you have an automatic you will need to remove the automatic transmission kick down lever which is connected to the intake manifold. There are two bolts attached to the bracket which you need to remove.
Two fuel lines will need to be taken off from the fuel rails in order to remove the cylinder head. You will need to pry the locks off with a small flat head screwdriver. To de-pressurise the system you will need to remove the small cap on the fuel line and press down on the little valve with the screwdriver, protecting your hands. There are specialist tools to remove the fuel line. It is a small ring like tool that comes in different sizes depending on the size of the line. You put the ring over the line and press down, which releases the gator clip and you can just pull the fuel line off.
Before removing the timing belt, make sure the two timing marks are lining up. There is a needle on the cam gear which should line up with the mark on the block. There is another mark further down the belt on the crank gear, so make sure these are lined up before removing the timing belt.
To remove the timing belt you must remove the 10mm nut on the tensioner, and once released push the tensioner towards the back of the engine. This is done using a pry bar, and once the tensioner is pushed right back, tighten the nut again to hold it in place. The timing belt can now be slid off and removed.
There is a 13mm bolt securing the alternator bracket to the cylinder head, remove the bolt to remove the bracket. There are three 10mm bolts on top of the valve cover which need removed. You might need to tap the underneath of the cover gently with a rubber or plastic hammer to loosen off the cover. Once loose remove this part.
There are ten 13mm bolts holding the cylinder head on. These will be on tight so you will need a good socket with a breaker bar to loosen these off. You want to turn the bolts a quarter of a turn, starting from the corner bolts and working your way towards the middle. Continue doing this until all bolts are removed.
Time to remove the old cylinder head. Strap the head to a crane and pull it up by levering it out until it is completely out of the way.
Remove the old cylinder head gasket.
Fitting the new cylinder head
Fit the new cylinder head gasket in place before lowering the cylinder head onto the engine block. Make sure that the gasket is sitting in the right place. You can’t afford to have this out of position slightly. You might want to clean out the threads on the block for the head bolts to go into and place the locator pins in to hold the gasket in place.
Connect the new cylinder head to the crane and lever it up. Place it just above the engine block. You may want to get an extra pair of hands to help lower this in. While you lower the lever the other person could guide it in place or vice versa. You will feel the locater pins clicking into place.
Once the head is on you will want to put a little oil onto the head bolts and slide them into position individually. When tightening the bolts, you will want to tighten each bolt to 44 foot pounds. Loosen them off again, about 2 turns and re-tighten to 44 foot pounds.
In sequence you can tighten each bolt a quarter of a turn. Again repeat this process, a quarter of a turn for each bolt in sequence. That completes the tightening of the cylinder head.
Now it is time to replace each of the individual parts in the correct sequence. Follow the list you made earlier, ensuring each part is securely fastened in place.
Once each part is re-connected the job is complete. Don’t forget to top up the different fluids before starting the engine.
Start the engine to test the engine is running smoothly.
That completes the cylinder head installation.