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How To: Head Gasket Change K Series (Pic Heavy!!)

252421 Views 183 Replies 79 Participants Last post by  comeinhandy, 
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Hi Guys.

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!!!




Oil Drain


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)

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B
Cheers Rob I'll not worry too much yet. I let it run for ten mins or so this morning while checking the main pipes to the radiator but neither even started to warm up (anyone know how long this should take?). Radiator and coolant rail bleeds fine but nothing from the heater bleed, no hissing or coolant, nothing!

Also, where the coolant enters the header tank there's just a small dribble, no strong flow like I'd expect to see.

Are there any valves etc which could be knackered and causing this? (It's got a PRT btw) cheers.
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M
There shouldn't be constant flow into the expansion tank - it is there to accomodate expansion as the coolant warms up and expands, but it isn't part of the coolant circuit. The small pipe that comes from the top of the radiator and the inlet manifold is a bleed pipe. You might get some flow through it as the air bleeds out of the radiator and cylinder head, and there may be some flow through it at higher engine revs, but constant flow of coolant through it at idle/lower engine revs would suggest a problem.

Did you take these pipes off and flushe them through? Emulsified oil gets into here when you have a serious HGF, but often doesn't flush out during a normal flush.

It is normal to fill the sump with cheap oil and the coolant system with plain water containing a flushing agent to clean out the emulsified oil/water mix from all the narrow passageways and nooks and crannies in the engine. Then after a few days usage, drain the sump and coolant system and change the oil filter again and refill with fresh good oil and new coolant water mix. There still may be emulsion continue to work its way out of the syatem for some time to come, so you just need to keep cleaning the expansion tank out periodically until it stops.
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B
Well I'm relieved about the flow into the header tank now thanks! I never cleared the hoses out properly because I caught the hgf as soon as the first signs appeared so didn't think I needed to. I like the idea of sticking a dishwasher tab into it so I'll try that!

I'm just concerned about coolant not flowing properly and waiting so long for the radiator pipes to heat up that the engine overheats! I suppose I'll just leave it running and watch the temp dial like a hawk.

Cheers for your comments guys!
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G
I never filled the tappers with oil after head skim does this matter? They are tapping but they did b4 should I change them? It's non vvc
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B
Overheated

My 1999 K series Rover got hot quick so I stopped and on inspection radiator overflow bottle is a oil mayo mixture, and all additional engine oil added to motor seems to also go to the overflow bottle, radiator seems not to heat and no sign of water on the engine dip stick. Obviously a serious problem has occurred. Any thoughts
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M
Emulsified oil in the coolant can only get there by two routes - head gasket failure or cracked head/block castings.
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E
angle - how crucial?

hi guys,
i did change my HG yesterday. i've tightened the bolts to 20nm, then i waited for about one hour and checked them again. all bolts had to be retightened.
after this, i've started the 90 degree sequence (4*90 turns).
problem and question is: i DON'T HAVE AN ANGLE METER/GAUGE, so i did this by sight. i did put some marker on the top of the bolt, but i'm sure it is not 100% accurate. so, HOW CRITICAL is that 360 degree rotation? i mean, if some bolts are a few degrees more or less, will it be ok?
thanks.
ps: does anybody know a final torque specification, so i can check all of them after the 360 degree turn?
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M
There is no 'final torque' setting - the 20Nm is to settle the gasket and ensure that the tightening sequence starts from the same point for all bolts. An angle tightening sequence is used instead of a torque setting so that all the bolts are tightened by the same amount and reach the same amount of extension it removes the effects of friction and torque wrench inaccuracy.

The 360 degrees is fairly critical but doesn't require an angle gauge - the genuine Kamax bolts have a mark moulded on them and when all the bolts are at 20Nm, you need to mark the alloy of the head next to each bolt to indicate where this indicator is pointing at the start of the angle sequence. Each phase of the angle tightening is not critical to within a couple of degrees, and on the final phase (at 360 degrees) the mark on the bolt head will again align with the starting mark you have made on the head.
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E
Thanks. Indeed, V. Reinz mention on their website that angle tightening is more accurate than torque. I did check my marks again, they look quite ok. because the marks were thick, there is no exact way to tell, but they do look good.

one of the bolts (no. 8) is a few degrees more tight (like somewhere between 12 and 1 o'clock, but more close to 12) and probably bolt no. 10 (the last one) is a few degrees less.

what can possible go wrong? i actually mean the question. like:
can i have damaged the gasket? can it be less tight and leak? can the bolts brake? and if the car will work, should i still worry for the future or not?
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E
PS: should i undo all the bolts, in reverse sequence and tighten them again to 20 nm and then 360 degrees more carefully?
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gnu
I'd leave it - you'd do more harm un-tightening and re-tightening if you are as close as you think. I've never used an angle gauge with a HG - just marked the bolts as MitC does.
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E
yeah, thanks. i did put the cover on.
the mechanics i know say it should be just fine... we'll see. i'll get back here with an update, one way or the other :)
hope for the best.
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E
here is a short update:
engine is up and running. no coolant in the exhaust, nor in the oil pan. as far as HGF symptoms, everything is good.

on the other side, i can see the infamous coolant external "leak" around the alternator edge... although i wouldn't call it a leak yet, it is only a "humid" place...

should i just let it be? or should i tighten furthermore 45 degrees each head bolt? what do you think?
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gnu
Eugen_piano said:
...on the other side, i can see the infamous coolant external "leak" around the alternator edge... although i wouldn't call it a leak yet, it is only a "humid" place...

should i just let it be? or should i tighten furthermore 45 degrees each head bolt? what do you think?
Click to expand...
Could tighten a little. Danger is you'll break or overstretch a bolt if you do too much. I've tighten further before with exactly this fault on an FAI MLS gasket. It helped but didn't stop the lhs front leak permanently.

The other thing you could do if it persists after tightening is a dash of radweld gold in the coolant reservoir - I expect to get a hard time for suggesting such a thing! :eek:mg2:

However, if you have replaced the gaskets property and you know all is well apart from this small seep, it will probably stop it at less cost and hassle than redoing the job with an elastomer hg or getting a replacement engine. With the values of mg-r's measured in the hundreds nowerdays it could be a practical solution.
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E
let's say, if i decide to further tighten 45 degrees, i should just go ahead and tighten the head bolts (simple as that?) or i should loose them a little bit and only then re-tighten?

yes, i was also thinking about some radiator substance, but i'm not in a hurry with any of the solutions above.

thanks for the input.
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gnu
Eugen_piano said:
let's say, if i decide to further tighten 45 degrees, i should just go ahead and tighten the head bolts (simple as that?) or i should loose them a little bit and only then re-tighten?

yes, i was also thinking about some radiator substance, but i'm not in a hurry with any of the solutions above.

thanks for the input.
Click to expand...
Bear in mind this is not a recommended procedure and there is a risk of damaging a bolt.

If the HG is quite freshly on and I hadn't run the engine like this for long, and and if I knew where I was on the tightening sequence, I'd just tighten each equally, say 45 degrees more.
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update

so, i didn't retighten anything. that humid spot just didn't look like it was worth the trouble.

good news is that the engine is clean, dry and sound. i actually cannot see anymore leaking anywhere near the head (or in other places). also, there are no signs of evaporated coolant.

idle is very good and i did have to take the coolant out in order to fix some connections, so i took the opportunity and checked entire coolant... crystal clear, no oil stains, no other mud.

today i've passed the system bleeding with flying colors and i think this concludes my business on this thread :-D

thanks everybody for the help.
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gnu
Eugen_piano said:
... and i think this concludes my business on this thread :-D

thanks everybody for the help.
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Good job :broon:
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M
I have a slightly sticky No 2 exhaust valve - gives erratic emissions readings and, perhaps around once a second, a slight hiccup in the exhaust rhythm, so the head will be coming off. It's the K8 as fitted to the Rover 100.

So this topic has been a valuable read, even though I replaced the head gasket around 5 years ago (with the first generation MLS + shim); I welcome this refresher - thanks to everyone. Being in no immediate rush to do the job has given me plenty of time to fully research the project; it's surprising how much info I've been able to pick up, not least of which was discovery of the existence of the modified "carbon-break" exhaust valve.

One tip I picked up to minimise/prevent coolant loss/weepage past the head gasket after fitting is to run, at idle for half an hour with the coolant system unpressurised to allow the viton coating on an MLS gasket to soften and bond to the mating surfaces without interference from weeping coolant, especially antifreeze, which lowers the surface tension of the coolant making weepage all the more likely. I had been contemplating first running the engine dry after fitting for perhaps 30 sec to a minute and letting it cool before adding coolant. And I may well do that and then run unpressurised to give the viton coating every chance to bond cleanly.

I also noted the absence of any mention in this thread of peening the fire-ring area (if indented) prior to machining to work-harden that critical area. In the trade magazine Professional Motor Mechanic (PMM) (Feb 2010), Ultra Parts, the manufacturers of composite and MLS gaskets, state "surfaces finishes should be commercialy smooth. A mirror finish is ideal" as well as "assembly conditions must be clinical". I don't wish to rekindle the skim vs no-skim argument, but the article states "heads should be refaced as a matter of procedure. Both the block and head faces must be flat and parallel within 0.003" of flatness." They also say not to panic if minor leaks are noticed between the head and the block because the viton or silicone sealing surface has to soften under initial run-up temperatures and, if neceassary, one should repeat the run-up procedure when cold to aid the self-healing process.

As mentioned in this topic, they state the liners must stand proud of the block. The PMM article states 0.002". I've more commonly seen figures closer to 0.005", but the one thing all are agreed on is that the liner heights above the block must be the same.

Head bolts should be lightly lubricated with engine oil especially under the bolt head and the head of any washers fitted. And Ultra Parts is adamant that no sealants of any kind should be used on the head gasket. (In my ignorance 5 years ago, I used Hylomar on the MLS gasket and shim without detriment, but I won't be repeating that error this time.)
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gnu
martinrub said:
One tip I picked up to minimise/prevent coolant loss/weepage past the head gasket after fitting is to run, at idle for half an hour with the coolant system unpressurised to allow the viton coating on an MLS gasket to soften and bond to the mating surfaces without interference from weeping coolant, especially antifreeze, which lowers the surface tension of the coolant making weepage all the more likely. I had been contemplating first running the engine dry after fitting for perhaps 30 sec to a minute and letting it cool before adding coolant. And I may well do that and then run unpressurised to give the viton coating every chance to bond cleanly.
Click to expand...
Not heard this before - where did you get it from? I'd sooner run it unpressurized rather than with no coolant; that sounds a bit risky!
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