Ruby, my daughters 850 with an 1100 engine has always used "a bit of water". 0.5 of a litre every time you drive her.
On the run to our place tonight Ruby ran very hot and even ran on when switched off.
Once it cooled down my daughter checked the oil and it was OK but the water was very low and a lot had to be added.
When I got home she restarted Ruby and she ran very rough.
The water had disappeared from the radiator so I pulled the spark plugs out and the centre two were wet and the tops of the pistons have a pool of glycol on them.
Is this common for the head gasket to fail between these two cylinders and into the water gallery as well ?.

Is it just the head gasket or have I miss diagnosed this.

Phil

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Will most likely be the head gasket, with a smaller chance there is a crack in the water jacket.
At the least you will need to change the head gasket out so will have a chance to inspect the head. It will likely need to be decked to remove any warp in the head as well, and this is a good time to have it inspected.

_________________
SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Had that happen to an old engine of mine. Made it home on 2 cylinders. changed head gasket and all was fine.

Losing water for a long time indicated a problem. Good condition engines do not use water.

cheers
michael

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the world is a book, and those who do not travel read only a page
66 Mini Minor sponsored by http://www.lifeonthehedge.com.au/ The Dog Harness Specialists
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Well we pulled the head off.
this is what Cyl 3 looks like. I can feel this "rust" area but think it might come of with a bit of Wet and Dry.

This is Cylinder 4. I can feel these bluish marks but suspect they will also come off with Wet and Dry.

This is the head gasket. Should it be Oval shaped around the cylinders. ?

This is a close up of the head between cylinders 2 and 3. It doesn't look like it seals properly. I would have expected a "sharp" line around where the gasket seals ?.


I am considering cleaning the bores with wet and dry and have the head skimmed and refit it with all new gaskets etc.
Does this sound reasonable.

Phil

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Find a job you love and you will never have to go to work !

That does sound like an excellent course of action.

The copper gaskets with the paper in the middle are a little dicey these days. Some work some don't and there's no second chances with them. Once they push the sandwiched paper out, they don't stop leaking.

Ask your parts supplier what they recommend. The Monotorque ones don't give me any grief on the small bores..

_________________
SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

Is it just the angle of the pics, or are those exhaust valves recessed a fair bit into the head?
It doesn't appear to have hardened valve seats on the exhausts. What fuel do you run? Do you run an upper cylinder flashlube at all?

You can see on the head gasket the blackened area in between 2 & 3 where it wasn't sealing properly and sucking the coolant in too!

Cheers Shane

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If it's not a Cooper S, the mini was designed to be modified!

Thanks Shane
We use 95 octane and Flash lube at every fill.
No I don't think it has hardened seats.
The car came with a heap of receipts for the work that was done including an engine rebuild in 2005.
The tops of the pistons are reasonably clean and are 020, so I guess that means it is 20 thou oversize.
The car has run well until this happened.

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I am surprised the bores didn't look cleaner... after all there was warm soapy water in there..... give it a good clean, change those fluids, new head gasket and another 9 years of trouble free motoring... or thats the theory anyway

Is there much point in getting the head skimmed I have blown up a few motors in my p plate days ( revving it hard ) and never skimmed the head the same head on all motors and is now on my every day motor and it's running fine and it's never been skimmed ....

I'm not too familiar with the small bore head gaskets, I've only had 1275's, but I think they do have that style head gasket ie. not round.

When you wet & dry the bores make sure you jamb a rag or paper towel down in the bore to catch and clean out as much as possible of your sanding "grit", and also clean around the edge of the piston and the bore down to the top ring. A feeler gauge may help here with the piston at top TDC or with compressed air. You don't want the "grit" to file out your bore or top ring!
I would also WD40 the bores after that to protect them from the elements until you get the head back on and the engine running too.

Cheers Shane

_________________
If it's not a Cooper S, the mini was designed to be modified!

Yes. The point is that the head gasket has gone. To give the next gasket the best possible chance of sealing properly, you skim the head to make it flat. Flat surfaces give an even pressure on the gasket leaving no gaps that could be a weak point. This is not a performance mod, just a precaution for reliability.

If you did not skim your head and reused it on multiple motors that all blew head gaskets, then there is a high probability that the head was not quite flat. From what you say, if the head gaskets are not blowing, then the head is probably relatively flat in the right places.

Alloy heads tend to warp more than cast iron ones. It is pretty much mandatory to skim an alloy head flat (waiting to get flamed on that one ).

Ensuring an even pressure on the head gasket is also why there is an order for tightening the head fasteners (nuts or bolts depending) and also why you tighten in steps to the final torque.

cheers
michael

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the world is a book, and those who do not travel read only a page
66 Mini Minor sponsored by http://www.lifeonthehedge.com.au/ The Dog Harness Specialists
It was a pleasure ausmini. I'll miss all you misfits and reprobates

I would also recommend pulling the studs out and cleaning up around the edge of the stud holes, all of the water holes (and perhaps oil holes if you are game - can't let any grit or chips into the oil system or your bearings will be shot in no time). I use a large drill bit to give a small chamfer to the edge of these holes. It helps to make sure that there is nothing in this area preventing a proper crush of the gasket.

I would also do the same to the holes in the head, then make sure that it is all meticulously clean before putting it back on.

cheers
michael

_________________
the world is a book, and those who do not travel read only a page
66 Mini Minor sponsored by http://www.lifeonthehedge.com.au/ The Dog Harness Specialists
It was a pleasure ausmini. I'll miss all you misfits and reprobates

Before skimming a head you can actually measure it for flatness.
I know it sounds silly but it is something that I prefer to do before cutting metal.

Well I shoved lots of rag down the bores and gave the bad spots a rub with Wet and Dry.
This is a photo of cyl 3 after cleaning. Came up smooth as

Any suggestions who to use in Sydney for a head skim. I live in Penrith and work in Rhodes so handy to those would be preferred.
Phil

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Find a job you love and you will never have to go to work !

From Mini Businesses topic http://www.ausmini.com/forums/viewtopic.php?f=41&t=83593

Russell Engineering
113 North Rocks Rd
NORTH ROCKS, NSW, 2151
Tel: (02) 9630 2195
Email: [email protected]
Website: http://russellengineering.com.au/

Graham does all the machining himself, and can get quite busy, however he would likely measure it on the spot to tell whether it needs it.

Mini Classic
2 / 27 Hope Street,
ERMINGTON, NSW, 2115
Tel: (02) 9874 7211
Mob: 0411 869 438 (Greig Malaure)

Greig would probably take it over to Graham's to do the machining anyway.

In Penrith, there are a number of places that do machining, just give them a call and check their experience with Mini or A-series heads. It should not make a lot of difference, but if they have done them before it helps with a quick set up. I have not used anyone out that way.

cheers
michael

_________________
the world is a book, and those who do not travel read only a page
66 Mini Minor sponsored by http://www.lifeonthehedge.com.au/ The Dog Harness Specialists
It was a pleasure ausmini. I'll miss all you misfits and reprobates