this is a copy of the post I wrote about headgasket failure and thought I would put it in FAQs for future refrence
its for 4 pot 2 ltr engines and not 2.6/3.0
before any work starts you need to confirm it is a leak/head-gasket fail.
Any grey gunge on the dipstick is clasic headgasket sign.
is there the same gunge on the inside of the oil filler cap and inside the rocker cover ? If your oil has turned to what looks like choc milkshake then this points to headgasket fail.
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Remove all the sparkplugs, fill the coolant expansion tank with water and crank the engine. if water comes out of one of the spark plug holes then this could be headgasket failure(99% the 1% being cracked head or block)
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Presure test the system :
I have not tried this but thought it through .as you are not local for me to look at the engine.
With the spark plugs still removed.
Trace the 2 pipes that go to the heater matrix,pick just 1pipe thats easy to get at union(where rubber hose meets metal pipe with j clip),connect a garden hose to the metal pipe and bung up the rubber hose.
turn on the tap that is connected to the hose and check for water leaks as this will preasurise the cooling system with about 1 bar of water.
Or block the top hose to expansion tank with mole grips/fuel line clamps,then connect the bottom hose to water preassure.
If water comes out of one of the spark plug holes then its head off time
If water leaks from a hose in the engine bay then fix leak and retest.
If water comes out of the side of the engine block then this could be a core plug or head-gasket fail.depending on where .
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Assuming that you find the head gasket has failed it's time to start spannering
Like i said its best to follow the instructions in the haynes manual UP TO A POINT.
Very important first job is to drain the coolant or water from the engine.if you don't do this then oil and water can drain into the head bolt holes as you dismantle the engine(when you put the bolts back in to reassemble the water gets squashed by the bolt and gives false readings on touque wrench)
follow the instructions for head removal but you can just remove the head with the exhaust manifold and inlet manifold still attached(unbolt exhaust manifold where it joins the downpipe)also disconect throttle cable,fuel lines,coolant pipes and air intake pipes/servo pipe as per haynes book but leave the throttle body/inlet manifold on the head.
so you take the head off with the manifolds still on.
remember to gradually undo the head bolts.
you will end up with this chunk to drag out from under the bonnet
you then need to inspect the head gasket,its not allways easy to spot where the fail is.and check the head for cracks
check the top of the engine block and clean it up,check the cylinder head for burn damage between waterways and the bores or oil ways.if the head is damaged then you will need to have it skimmed and this will mean removing the manifolds.(about £20 for a skim here but you are in london so i don't know the price).
If this is the case then you may as well strip the head and replace the valve stem oil seals and all other gaskets.
in any event you will need to give all the parts a good clean,and clean the breather mesh in the rocker cover and all the hoses.
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this part is a bit naughty
If you are on a real tight budget you can skimp on parts.
remember if you do that you will have more work on your hands if any old parts fail
Its always best to have the head skimmed(£20) but if it is not damaged then you can get away without it,
It's allways best to fit a new waterpump(£16) as you have to remove this while doing the head,unless its been recently replaced . if you do use the old pump then use blue instant gasket on the "o"ring seal.
It's allways best to use new head bolts(£15)but the new head bolts often come with torx heads so if you don't have a socket(£5)its more expense.I have in the past cleaned the treads on the old head bolts and reused them.
It's allways best to replace the cambelt(£10 c20se)(cambelt and roller kit c20ne £37)unless you know its recently been done.
all the above is best replaced but if you want to do the job cheap to get it going again then it can be done without. BUT on your head be it !
If the headgasket is the problem(once you confirm)then it might be worth getting the parts because you know the car will be ok once done and you will know that the bits have been replaced so you will not have to replace them again.
hope this
SHORT post will help you
