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MG MGA - Cooked it!!

As with many things in life this started as a small issue which could have been solved cheaply if done at the time but has now led to a more complex fix being needed.
It started with the oil/water gauge failing about 6 months ago. The water temperature slowly got less and less until it eventually did not move off the pin.
That was ignored as I was channeling all my time (and money) into my Jaguar restoration.
At some point however the lower radiator hose pin-holed and started leaking water... you can see where this is going now?
My monthly fluids check spotted a small drop of coolant gone but it was not much more than normal. However last week the engine started running rough and when I stopped there was a cloud of steam coming out of the radiator overflow - oops.
I let it cool and then topped up the radiator and drove home.
Spotted the leaking hose and changed it. Changed the temperature gauge and started up again.
Still running rough. Checked the compression and found that cylinders 3 and 4 where low. Worst still cylinder 3 was spitting out water!!
Cylinder head off I could see that the gasket was blown between 3 and 4 so the head and block was cleaned off and a new gasket fitted.
Having torqued it down and re-fitted the ancillaries I started up only to see that water was still seeping out at the gasket. A re-torque when hot slowed it down but it still is there.

Next solution is to have the head skimmed. I hope that doing this will solve the problem. If not then I will need to remove the block.
Anyone any similar experience to draw from to say whether the block is also likely to need surfacing?

Neil Purves

Can't say but a quick check with the head off should tell you all you need to know. Seriously, the block being Cast Iron, it shouldn't, since you had coolant (steam) in the engine at the time, but again...
Before you skim, check your mating surfaces and insure that you don't have any pulled thread holes keeping your gasket from sealing proplerly. Check both sides to insure that they are flat-no sense doing work you don't need.
Good luck.
Mike Parker

Neil, use one of the black composite head gaskets with the red sealing material round all the waterways. They are intended for 1800 engines but are ok on 1500 and 1600 blocks. This sort seals much better than the copper/asbestos type. They are mentioned somewhere on Barney's site.
Lindsay Sampford

I would get the head pressure tested (with water at 190 deg) before having any machining done - I cooked a head after a heater valve failed and pressure testing showed a crack in No 3 exhaust port. Unrepairable replaced with alloy head - but that is another story!
Mike Ellsmore

Is there any steam coming out of the exhaust?
J Bray

Although there is now no water to be seen outside the block there is still a bit of steam from the exhaust after startup and the first couple of turns of the engine are a bit of a struggle.
As mentioned I changed the head gasket and then warmed and re-torqued at which point it was externally leak free, I think however the water forces itself into the cylinder when under pressure.

Neil Purves

Sounds like a crack in the cylinder head, so check very carefully when you remove the head as they are not always easy to see.
J Bray

Don't run the engine much more, as antifreeze in cylinder can lead to sticking piston - especially since you note stiff cranking. I broke my crank shaft due to a similar water leak around head gasket !

Chuck Mosher

assuming that you have put fresh water in the radiator after replacing the gasket drive the car to your local (friendly) garage and ask that they test the cooling water - There is a blue liquid test that changes colour to yelllow if combustion gases are present in the coolant. Also check the colour of your plugs, leaking cylinders very often have different plug colors.
J H Cole

This thread was discussed between 17/01/2012 and 25/01/2012

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