Sorry, was supposed to pop this on a week or so ago.. just got round to it.
Perhaps one of the biggest problems or should I say...fear's... of any Vehicle owner is the DREADED Head Gasket... but no need, with very basic DIY knowledge, you can change it, just as I have.. Below is a step by step guide to what I did to change the Head gasket. Please note though, A Haynes manual is paramount to making sure the job is done correctly, while this shows how I did it.. it doesn't mean its right!!!!... it just worked afterwards...
What is important though, is finding why the head gasket went in the first place, as just replacing the new gasket may see the same problem weeks later! Prime suspects are:
a)Coolant cap (Seal not working causing no coolant pressure)
b)Thermostat, for the sake a few quid, replace it..if you really must test it.. dangle it in a cup of coffee (Yes I know....) But the temperature is around 88 degrees. and should open.. if it doesn't replace.
c) Water pump.. usually makes a noise or leaks when it fails
d) Blocked radiator, causing overheat, back flush with hose (Low pressure) what comes out of it?
e) Coolant leak..check pipes, radiators..unions..gaskets.. Renew as needed
f) Cracked Head...will need to be replaced..ebay is a good place to start or scrap yard. Get a pressure test done on it by a garage
g) Damp / wet liners moved ...should stand a little proud.. if they sink, no gasket will ever seal it, unfortunately the engine will be scrap. (read part about moving crank with head bolts removed(DONT))
Step One.. Make sure you have a good clean environment to do the job in.. make sure both you and the engine are protected from the elements.. I got a Gazebo.. £12.99 from Argos A small table for tools and parts, and somewhere to store the parts you take off.. Remember to clean as you go.
Step Two.. Get to know your engine... have a good ol' look around it, see any signs of wear and tear and of course, what it looks like when you put it back together!... taking photo's will help you, should you have the odd 'pipe' or wire that has no place to go!! You would be surprised how many bolts I had left over at the end!!!..All now found their place
Some images of what head gasket failure looks like!!!
Step Three.. Disconnect Air filter.
Step Four.. Disconnect All coolant pipes from radiator and engine. (A good opportunity to rinse them all through and check for damage) Crusty build ups suggest coolant crystallization from leaks.
Step Five.. Disconnect all vacuum hoses and to ECU and store in safe, dry place. Its also worthwhile labeling them so you know where and how they have come off.. (I used labels with 1:1 and 2:2 etc. so I knew where they attach)
Step Six.. I find its easy to label the leads.. Although I painted them ... a sticky would be better!!! We live and learn don't we lol...
Step Seven.. Strip down distributer parts and remove them.
Step Eight.. Disconnect all cables from sensors but leave Spark plugs in holes. (Unless you want to clean them up)
Step Nine.. Remove camshaft cover and discard gasket. Note the colour of the oil... looks like chocolate milkshake.. same thickness as well...
A Close up of the 'goo' Remember to clean this out and the mesh filters (I used a hose.. worked fine)
Step Ten.. Depressurize the fuel system, loosen the nut and remove pipe.. Plenty of rags to the ready.. NO SMOKING and plug gaps to stop debris entering the system.. Due to spillage, its worth while letting any evaporate...go get yourself a cuppa!!! Any sparks can be fatal!
Step Eleven.. Remove the inlet manifold (Check bolt sequence in Haynes) Note the gasket has also failed on this one.. Irrespective, this gasket must be replaced when removed. Also, on Fuel injector models, remove the rail and on carburettor models remove this.. a long with throttle body and cable.
Also, unbolt exhaust manifold.. this is an absolute %^%&^$& to get off!!!, use plenty of WD40 prior to even contemplating taking these bolts off, you might want to leave it on as will make a good handle and take the exhaust off from the next union down. These will still be difficult but beter to break or drill out if needs be..
Step Twelve.. Remove cam belt cover..
Step Thirteen.. Insert Cam locking tool (Get off ebay of motor shop, few quid) Make sure the inlet & Exhaust marks line up. Its also worthwhile (For how I did it) Is to mark the cam belt with direction and position marks.
At this point.. depending on if you are replacing the cam belt (Mind was done 2k miles ago so I left on, will depend on what you do now. Either way, using an alan key and a number 8, remove the tensioner. Its good practice to replace this, if you are keeping it, discard bolt or when you refit use some 'Locktite' to stop it working free with vibration.
A Good video here : http://video.google.co.uk/videoplay?docid=4217575705633360863&q=cambelt+change
Step Fourteen.. Remove Thermostat (Good idea to replace, Along with the Gasket and o Ring)
This is now how the engine bay should look... lots of working space...
Time for a cup of tea.....................
Step Fifteen.. Now for the head.. Make sure you have the right bit.. the upto date sequence and most inportant...don't rush!!! its a three stage tightning sequence.. There is no need to have the re tightened after..no run in... The nature of the engine means you cannot rotate the crank..or the block as the damp liners might move.. so care is needed here. (Each bolt if re using should be placed into a cardboard holder with numbers written on them so you know which is which) Also if re using they must all be measured as they are stretch bolts, if they are over.. new ones must be used.. if more than one out.. replace them all (Don't bother with ebay..as some horror stories of them snapping with refit!!)
Working in sequence, untighten the head bolts...
Once all the head bolts have been removed.. Gently rock the head towards and away from you (A strong L bar into two of the head bolt holes will help) To break the gasket seal.. Once broken get help to lift up and out the head.. Be careful not to drop it and don't place on hard ground using the gasket mating surfaces as a rest as scratches will ruin the head.
Step Sixteen.. Now remove all traces of gasket and carbon built up.. checking for pitting.. cracks and other damage.. Use either a wooden or plastic scraper, not metal in case it scratches the head.. Extreme care should be taken.. Take your time Don't use sandpaper!! The cleaner the mating surfaces...the better!!! (Must say I used oven cleaner lol.. Mr muscle loves the jobs you hate!!!) Be careful though due to the acid content.. I brushed on.. scrubbed off!!.. Also as it was wet. I used WD40 to stop it oxidizing and also rinsed out all water canals.
Also using a true straight edge, both diagonally, vertical and horizontal. place it across the head and check for warpage (Machine shop will also do this for you)
Don't listen to the nonsense of Get the head skimmed... If it aint warped.. DONT SKIM!! It removes the heat resistant surface and increases compression. And is just a waste of money! If it is warped though, you will need a skim. Don't bother taking it to a garage.. go straight to a machine shop who will do it for you. A lot cheaper and only what a garage does!
Step Seventeen... Fit new gasket.. If using anything other than the landrover gasket (I.e. One with red beading) Check for damage and make sure there are no breaks in the bead (I had to get two as first one was faulty) I used composite (£33 for the full set!!) (Don't bend or distort it!)
Thats the hardest part over with!!!!!
Now refit in reverse order.. Care should be taken when re fitting the head and get a friend to help as moving it round looking for the dowel holes will scratch the surface... Also... the new metal dowels might be too big.. slightly increase the dowel holes in the head with a drill.. The metal is very soft.. be careful!!!
I hope this manages to help someone.. Anyone with more to add or alternative methods.. Feel free to add, again this is just how I did it and its working fine Although will probably add more as I think what I have missed out.
Get good quality oil and replacement filters.. Although no run in is needed.. its a good idea to drive like a granny, try not to go above 4k revs if you can for the first 500 miles and check the water levels after each trip Mine lost a little water for the first couple of days as the airlocks were removed but settled down and the water level is now constant.
Also make sure you replace with the right mix and type of coolant. On the expansion tank there is a circle label.. Should tell you on that the type.
Once again, this isn't a job you should fear.. can be done over a weekend, especially now the weather is getting better.. So many cars on ebay that people sell for next to nothing because of this problem.. The most important thing to remember, if you suffer head gasket falure.. Don't drive it...don't let it over heat and if you need to get home make sure you keep checking the water level. Furthermore, K-seal really does work as a get you home system (Not a good idea to just leave it) So worth keeping some in the boot....
Below are the pics of my car all working and now with nearly an extra 1000 miles on the clock with no problems (Touch wood)