hi all my name is Joe, I'm new here but i have a question and I cant seem to find the answer.

So i brought a ford fiesta 1.6 tdci 2013 , zetec s , the 95bhp model off my brother with oil in the expansion bottle.

it starts and idols fine so i paid him and took it home , 100 yards down the road,, my friend and i started to diagnose a few issues and together we did a load of regular manintance, cleaned all the pipes, replaced the rad (old one full of oil), new oil cooler, new thermo housing, new cam belt deisel filter etc. Rebuilt and it started and idols fine for the 2nd time , (this time the heaters work in car too the first time they wre very poor) but we still get alot of pressure in the expansion tank. so we are suspecting head gasget or something head related due to my brother driving it after the problem was first noticed and overheating it (not recomended i know but thats where im at). the oil looks ok! and there doesnt seem to be any more oil in the water so we are thinking gases returning to the water bottle or something like that anyway. We didnt test it just the next logical step was head i guess.

any way we removed the head!, upon lifting the head up we hear a rattle like a small bolt fell out and rattled it way to the floor, however upon inspection we found a small black cylinder type "valve" covered in oil sitting on the floor, so we can only presume it fell out the bottom of the head as we lifted it off? has anybody seem this before, friends of mine have basically told me its to prevent oil presure build up in the head and dumps oil back in the block if the pressure is to high. 

However i cannot find a name for it? nore any documentation regarding its purpose or location? , there is a rubber seal but im not sure of its orientatrion as it was laying on the ground when i found it. it has a ball in the bottom that seems to be sping loaded , if u press the ball a bit of oil comes out.

photos attached , i hope some clever person has seem this before becuase its got me stummped. also im wondering if anybody has any opionins ref the sysmptons, of the water bottle pressure also, if i leave the gap off the engine runs fine, it i put the cap on tight the pressure builds instantlty and once i remove the cap the water blows out everywhere. could it be anyting other than a head issue. ive sent it for skim and test in any case. 

Pressure relief valve - 6K702 on this picture

@TomsFocus Thats a massive help thank you so much . just out of curiosity i gooled the number 6K702 and it didnt being up the same black cylinder .. but the image you sent looks axactly like it. what site it that from ? is it something i can access for more images and stuff.

Just now, joe260986 said:

@TomsFocus Thats a massive help thank you so much . just out of curiosity i gooled the number 6K702 and it didnt being up the same black cylinder .. but the image you sent looks axactly like it. what site it that from ? is it something i can access for more images and stuff.

That's a catalogue number, not a part number.  The Finis part number is 1235976.  The website is called 7zap.

Cylinder Head FORD Fiesta 2012- (CCN) (7zap.com)

 

@TomsFocus hi again, i hope you are well and thank you for your time on this, i finally manated to rebuild the head yesterday and we fell into a little snag,,, the image you sent showing the valve also shows it location and orientation , brilliant so we thought. The issue was the line on the image actually points to a bolt hole so the valve 100% cannot go there, the hole next to the bolt hole which is the one in the block with the half moon shape seems to be the only other hole in that area where it would fit so we went there.. fingers crossed. !! :-{