without being rude, i did a head without ever doing one before the other day and managed to get it all prepped for the skim shop in 2.5 hours - so yeh, its pretty easy.
1. Disconnect any wiring looms, be sure to mark or label them if they're not colour coded. And remove the water pipes that go into the thermostat housing, ensure you drain the radiator first to prevent cross contamination of the oil and water channels.
2. Loosen the alternator at the top and remove the aux belt and the crank pulley (mark the outside of the crank pulley)
3. Use the timing marks on the block, or common sense, to lock the head at TDC (not dead important, just makes life easier). Top dead centre is where number 1 piston (closest to the cam gear) is at the top of its stroke. Most cars (check your Haynes for confirmation), will have notches that you can actually drop pins into to lock the cam gear and the crank pulley at TDC. Mark the crap out of it with tip-ex anyway for good measure.
4. Loosen off the tensioner (now's your time to replace it if its not been done in about 40-60k), and remove the timing belt. Inspect the belt for wear, if you can see the ribs on the outside of the belt, then replace that too.
5. Unbolt the mani > downpipe (if that's too difficult), then you can remove the downpipe > center pipe and wiggle it out with patience (bear in mind the head is heavy, so you need a little strength about you)
6. Disconnect any fuel lines and air ducts for the throttle housing, remove spark plugs and HT leads (label them if you don't know which is which).
7. Remove the rocker cover, then proceed to unbolt the 10 head bolts in the right sequence (check your Haynes) a half turn at a time, then you'll fine after 2 passes, you can undo them with your fingers.
8. Lift the rocker assembly off and put it somewhere safe, then lift the head off.
9. Clean the old gasket (if neccessary) with something soft, a wooden or plastic scraper, some people recommend 320 grit wet and dry - but its not a sensible idea. And be especially careful cleaning the underside of the head, its alluminium - VERY SOFT!
Thats pretty much it, then refit in reverse. Clean the bores and check them for scratches, also check the piston. Sometimes you get deposits in there, just hoover them out. You don't need the head skimmed when you remove the head (unless the head gasket has seriously blown), and if it does need skimmed its £25 from any machining shop - ensure they lap the valves at the same time too. You can check the head for warping using a straight edge and a feeler gauge (bit crude, or you could ask any machining shop to do it for about £5).
Things that do NEED replacing are...
Fresh Coolant and Water (£2)
Head Gasket (£15)
Head Bolt Set (£15)
Things that CAN be replaced if the car is due for its 40-60k service are...
Tensioner (£12) - Again, if the belt looks worn, odds are the tensioner should be replaced too.
Timing Belt (£7)
Aux Belt (£4)
Water Pump (£25) - Not hard to change, and difficult to test the old one (can only check for bearing play), its up to you if you want to change it - not always neccessary though!
Oil (£10)
Oil Filter (£3)
Spark Plugs (£10) - Only need replacing if they look worn, no point doing it otherwise
....So I did go on, to ensure people do get the picture. Removing a head isn't that difficult, and certainly doesn't justify taking it to a garage to pay £400 for a Head Gasket replacement where they'll just use the same stretch bolts! It can be a little daunting but surely its something worth learning to try?
Tools needed...
Angle tool gauge (on some cars)
Torque Wrench
E Type Star Sockets
A Standard Tool Kit
