A series sport (pre-1995/C20NE) - Removing Cylinder head
From FogWiki
Contents |
Applies to
- A series SWB, C20NE Engine/Pre-1995
Required equipment
- A good "large" ratchet set - one that goes from 10mm up to about 24mm sockets, as well as a long extension bar. You may need a wrecking bar as well, or at the least a piece of pole or similar that you can extend the ratchet handle with to get some leverage.
- A small ratchet set - one that goes from 6mm to 10mm - for getting to those pesky nuts in tight places.
- A good range of ring spanners
- A set of large molegrips
- A large adjustable spanner (that will open to about 50mm).
- Various screwdrivers
- A set of Torq bits
- A set of Allen bits
- Wire brush
- Set of sidecutters/pliers
Other bits you will need:
- A large can of WD40
- A tube of copper grease
- A large supply of rags & kitchen roll (you will specifically need rags)
- A bottle of spray on "Gunk" for degreasing
- A large supply of little bags and a marker pen, or a very good memory!
- A bottle of tipex (honestly!)
Difficulty Level
- Medium
Estimated time to complete
- 6-8 hours
Method
Stage 1 - Get some room
The first thing to do on a '94 sport is to completely ignore the Haynes manual. If you have a pre or post 94 then your mileage may vary with the manual, but I soon found that it was little help.
Before you start anything else, spray all eight of the exhaust manifold bolts with WD40 and leave to soak ...
You need to get yourself some room to work. Disconnect both terminals from the battery, and remove the battery from the car. It will make getting to the exhaust manifold easier, as well as giving you a surface to put tools/nuts/bolts on. Disconnect the connector that goes to the coil, and you should be able to move the positive cable all the way across to the other side of the engine bay and out of your way.
Next, drain your radiator by either the drain plug if you have one, or if not then by simply removing the pipe that goes to bottom of the engine from the radiator. Disconnect the rest of the hoses, then undo the brackets holding the radiator in place. Remove the radiator from the engine bay, carefully empty the water out and then flush it out with a hose until the water runs as clean as it is going to get.
Next, remove the air pipe that goes from the filter to the engine. Have a good look inside, as you will probably find it covered in grunge. Good time to get the "Gunk" out and some of that kitchen roll.
Stage 2 - Auxillary equipment
Next comes the auxiliary belts. First one to tackle is the power steering belt, which is the front one of the two. First, loosen the nut at the bottom of the pump by a turn. Next, at the top of the power steering pump there is a large threaded rod with a nut each side of where it goes through the pump. Undo the nut closest to the engine and move it a fair way down the thread. Next, turn the other nut so as to move the pump towards the engine block, relaxing the tension on the belt until you can remove it. Take it off and inspect it to see if it is suitable to refit. At the time of writing this, a new belt was £4
After you have removed this, move on to the alternator. Again, loosen the bolt at the bottom of the alternator, then the bolt at the top that goes through the tensioning bar. This should allow you to rotate the alternator to remove the second belt. As with the power steering belt, inspect it to see if it is worth refitting or not - again, at the time of writing this a new belt was £4.
Once you have the belts off, next comes the fan. This is where things get tricky, and just shows how far out the Haynes manual is. The shaft has two flats cut in to allow you to grab it, and the fan has a large nut onto that shaft. Looking down behind the fan you will see where the split is very clearly. Put your molegrips on the shaft, putting the jaws on the flats. Rotate it round to rest the handle of the grips on the power steering pump. Next, get your adjustable spanner and place it on the nut of the fan. Now for the skin-removing part - The nut is a reverse thread, so you need to turn it to the right to loosen it. You might need to take a hammer to the adjustables to break the seal. Once you have managed to loosen the nut, unscrew it and remove the fan.
Once the fan is off, take a 10mm socket and remove the four bolts holding the fan pulley onto the shaft. Remove the pulley and put to one side.
Next, you need to remove the alternator. Undo the top bolt and remove. Carefully undo the bottom bolt, making sure you do not lose the nut or washer. Once the nut is off, remove the bolt (this is where you need a second pair of hands!), and pull the alternator away from it's mounting. put the bolt back through so you know where it is. Carefully rotate the alternator so you can get to the connectors. There should be one 8mm nut and one 10mm. Remove the nut and take the wire off. Put the nut loosely back on so as not to lose it, and repeat for the other connector.
As a suggestion, once the alternator is off, take the nuts off again, clean up the connector with a touch of WD40 or the like and then put a coating of copper grease over it and put the nut back on loosely. Take a wire brush or similar to the terminal just to clean it up, and move to one side. Rinse and repeat as necessary. Once done, put the alternator to one side and we go on.
Now get out your bottle of tipex. Carefully mark the HT leads to your spark plugs so you can remember which order they go back on (I marked mine 1 to 4 front to back by using "stripes" of tipex to denote number). Give the tipex a moment to dry, then carefully pull the leads off the sparkplugs (remember not to pull by the lead itself as this could damage it). Unclip the leads from the guides attached to the rocker cover and move out of your way. Get a 6mm spanner and undo the three bolts that hold the distributer cap to the back of the engine. Carefully remove the cap and the plastic gasket. Undo the HT lead to the coil and the whole unit should be free. Take a moment to check the state of the cap inside. If needed, clean up the terminals etc, then put the whole assembly to one side (somewhere dry!), then go back and remove the spark plugs and check them over, clean as necessary and put to one side.
Next, use the tipex to mark up your injectors (four yellow plugs along the top left of the engine as you look from the front). Once marked, undo the connectors. At each end of the rail you will see an earth strap. Undo these two and the injector loom should now be free and can be moved out of the way.
Stage 3 - Timing belt
On the crankshaft pulley (one at the bottom of the engine with the double pulley on), there are again four 10mm bolts holding the pulley on. Put the car in gear so the engine doesn't turn, undo the four bolts and remove the pulley. Once this is off you can undo the 10mm bolts holding the front of the timing belt case on. Remove the front of the case and put to one side. Undo the connector on the wire that goes down from the top of the engine, inside the timing belt case and to the bottom of the engine (crank sensor) and move to one side.
Important - Before going any further, it's time to set your engine to top dead centre (TDC). On the top pulley inside the case, you will see what looks like a little nick out of the front of the pulley. This is your TDC mark. You should also see a small nick out of the top of the timing belt case. Take the car out of gear, and using a socket on the nut on the crankshaft (bottom of the engine), slowly turn the engine until the two nicks line up. Put the engine back into gear to help prevent the engine turning again.
In the middle of the arrangement of pulleys, you will see a small piece of metal poking up and to the left from behind one of them. Carefully push this across to the right, which will release some of the tension on the timing belt. While holding this over, carefully slide the belt off the top (camshaft) pulley. Check the belt for signs of wear and tear, but most people will tell you it is probably a good idea to replace it anyway. At the time of writing, a new timing belt was £11.
Next undo the nut holding the camshaft pulley on. Remove the pulley and put the nut back into the camshaft so you don't lose it. At the back of the timing belt case you will see some allen bolts holding the casing on. Undo and remove the top two bolts, which should allow you to gently east the casing away from the cylinder head. You can of course remove all the bolts and the casing, however removing the top two should prove to be sufficient.
Stage 4 - Various pipes
This might sound a bit of a cop out, but it's not. Take a close look and you will see what pipes need to be removed to allow the head to come off. There are a few. The key ones that you need to know about are:
- The vacuum pipe that goes to the back of the injector assembly. This is a formed plastic pipe, and can be a swine to remove. It may be easier to remove it from the vacuum cylinder end (bulkhead directly in front of the drivers side dash) rather than trying to remove it from the engine side.
- The send and return fuel lines. Make sure you mark these two up so you know which order they go back in. On my vehicle, there was a small piece of copper pipe on the end of each, and it was a bit hit and miss as to which end would come off. Be prepared to catch any fuel left in the pipes.
Stage 5 - Exhaust manifold
This is where soaking the manifold bolts in WD40 will hopefully pay off. Carefully undo each of the eight bolts holding the manifold on. Depending on how long the manifold has been on for, you might need to apply a bit of pressure with a wrecking bar or similar, but take it slow! If a manifold bolt snaps off, it can be a real pain in the backside. If you don't think it will give easily, go back and apply a bit more WD40. If all that fails, you might need to apply a bit of head to the nuts to remove it, but make sure the WD has evaporated off first, as it is flammable!
Once all the nuts are off, carefully pull the manifold away from the head. You might find that the gasket is still separate, or it might be that it has welded itself onto the manifold. If the latter, cover up the side of the block with a rag to stop any flakes going into the engine via the spark plug holes, and then take a wire brush or some sandpaper to remove the remnants of the gasket from the manifold.
Stage 6 - Removing the head
There are ten bolts holding the cylinder head down, and these need to be undone in the correct sequence to ensure that the head doesn't warp.
(Bulkhead)
7 -- 8
3 -- 4
2 -- 1
6 -- 5 10 -- 9
(Radiator)
Start with bolt 10, then work backwards in numbers to 1. First, just crack off the torq on the bolt - Put the wrench on and undo the bolt slowly. You will hear it "crack" a few times as it gives, then it will start to turn. Repeat all the way down the sequence, then go back and undo and remove each bolt ‘‘in the same sequence again’‘. As each bolt comes out, inspect it to see if there is any oil on the threads. If there is, you will need to make sure you clean out the bolt holes in the block before trying to reassemble the head, as oil doesn't compress and it will make it impossible to torque the head bolts correctly.
Important - If you plan to reuse the same head bolts, make sure you keep a note of which bolt is for which hole, or you may cause problems when you come to refit. The easiest way is to get a piece of cardboard, write the numbers 1 to 10 down one length of it, and then push the bolts through the cardboard next to the appropriate number when you take them out. However, again, you are probably much better off replacing the head bolts altogether, and at the time of writing, a new set of head bolts was £17.
Once the head bolts are off, you can remove the rocker box from the head by carefully rocking it left and right. Do not try and use a screwdriver or anything else to crowbar the top off or you can damage your engine. You may need to persuade it off by using a block of wood and a hammer, but take it easy. Slowly lift the rocker case off, so as not to lose the shims etc. Once the rocker box is off, get yourself 8 plastic bags or little containers and number them 1 to 8, and then working from front to back, take off the shims, and carefully remove the hydraulic lifters, placing them in the appropriate bag for safekeeping.
Now you can carefully remove the cylinder head. Again, do not try and crowbar/pry this off with a screwdriver or the like. Be careful when moving the head, as you will probably find that hose that you didn't see needing to come off. Make sure the exhaust manifold is out of the way when you try and remove it. All being well, the head will separate fairly easily, leaving the head gasket in place on the block, located on the two locating collars top right and bottom right (bolts 8 & 9).
And that's it - head removed
As I said, there is probably quite a bit that I have missed here, and possibly the wrong name here and there, but remember that I am not a mechanic. None of this would have been possible without the selfless help of some amazing members of FOG who give their time so freely, and are patient with even the most un-mechanically minded person such as myself.
Submitted by
- Jay
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Categories: Engine | How To | A series
