I have recently bought a 2005 Focus 1.6 petrol. After trawling the forums I've learnt a lot about the washer jet issue. I have replaced the washer jets, bought a Volvo cover and used a mini hose attachment to suck out the remaining water in the spark plug well. I want to fit new plugs, however, I found this in the 3rd spark plug well

Looks like a screw/plug has rusted through and was sucked out when I cleared the water.

Is this one of the core plugs? Any suggestions on how to fix this would be greatly appreciated.

Have you checked your vacuum to see if anything was sucked up? What do the other plug holes look like?

is it a cylinder head bolt broke off if it has it will be very hard to remove

It's not a cylinder head bolt.

Looks like it could be a threaded hole for a cylinder head temp sensor, presumably its between plugs 2 and 3.

still be hard to remove wouldn't that show up as overheating with out it

Doesn't look like anything has snapped or missing to me.

It probably isn't fitted with one.

It's not a cylinder head bolt.

Looks like it could be a threaded hole for a cylinder head temp sensor, presumably its between plugs 2 and 3.

Yes, its between 2 and 3. No warning lights are on and there are no loose wires or anything in there. I checked the vac and couldn't find anything other than bits tiny of rust. I'm not convinced those spark pugs are coming out, judging by the state of the wells.

This one. From the looks of it the previous owner knew nothing about this and 10 years on this is the result.

The rust on yours looks not too bad compared to some I've seen.

So, having trawled through the internet, it looks like you're right Stef this is where the temperature sensor would be on other ford engines. I can only assume that.....

a) there was a blanking plug in there and thee top has has rusted away

b )there used to be a temperature sensor that has been removed

either way, would I be right in assuming that this hole leads to the cooling system and if the hole was open, coolant would leak into the spark plug wells?

Any idea how much someone would charge to remove and re condition the cylinder head? At this stage I'm guessing that this would be worst case scenario.

Cant you just screw a bolt in there to blank it off again?

It looks like there is a partial bolt in there sealing it anyway, its hard to tell from the photo though.

No it's only a cylinder head temp sensor not a coolant temp sensor so nothing will happen if it's left open like that

Phew! That's put my mind a rest, thanks Stef and others for the quick responses.