Water leak into a cylinder

[don58van]

Hi

I am pretty sure my 948cc has developed a water leak into number one cylinder.

It started running roughly. There is a bit of bubbling in the radiator. I took all the plugs out and spun the starter--some drops of what I am pretty sure is water splashed out of number one. A gauge showed that compression is significantly down on number one.

Is this a rare occurrence for these engines? I often read that others have the head gasket go between cylinders 2 & 3, but I don't see much on water leaks.

I am assuming that in all likelihood I just need to replace the head gasket. Correct?

Don

[bmcecosse]

It can happen - so yes - off with it's head!

[POMMReg]

Does the water need topping up regularly?

[BLOWNMM]

Don
Make up a fitting to screw into the plug holes ie. silver soldering/welding or what ever you can, even an old compression tester fitting to attach to a compressor. With the radiator cap off pressurise each cylinder to be tested and if there is a gasket leak you will see bubbles through the radiator filler neck.
Cheers Bob

[bmcecosse]

For all the effort involved - just change the gasket ! Take the chance to grind in the valves - and check the surfaces are absolutely flat and spotlessly clean. Certainly don't run the engine again until you find out what's going on.

[dalebrignall]

i love it when roy says off with its head just makes me laugh dont know why , good luck with the head gasket change

[bmcecosse]

Queen of Hearts.......

[don58van]

Thanks to those who gave advice.

I have taken the head off and confirmed that water was getting into number one cylinder. The bore feels rough, so I suppose it will need honing at the very least . There seems to be a bit of a score in number 4 too .

I need to make a more detailed inspection to work out exactly how the water was getting in.

Don

[bmcecosse]

Hmm - well if the gasket looks ok - could be crack in the head, or in the block.

[don58van]

I've had a chance to have a close look at the head, deck and gasket.

Here are some pix.

[frame][/frame][frame][/frame]

So the path of the water leak is quite clear. No head or block cracks.

It was a really fancy gasket too -- a 'Monotorque'.

Perhaps the front head bolt, nearby, wasn't torqued down correctly (not by me -- this is the first time I have touched the head).

The puddle in the piston bowl is oil, not water. There was quite a bit of water there when the head came off, but this is after I had cleaned the cylinder and piston top. I tipped some oil in and coated the cylinder wall to stop any more rusting until I decide what to do next.

I note that the exhaust valve seems to be recessed quite a bit -- fortunately the others look much better.

Don

[bmcecosse]

I've never seen such a sunken exhaust valve.... I suggest unleaded seat insert is the way to save the head.