16v ztec has antifreeze on top of spark plugs

https://www.autodoc.co.uk/car-parts/spark-plug-10251/peugeot/207/207-wa-wc/26630-1-4-16v

Absolutely no,please check your coolant bottle and make sure it has antifreeze in green/yellow so we know that you are not leaking it into the engine if the liquid is antifreeze is it in all cylinders or just one ? Or is it water? This needs to be done today and if it's water and your coolant bottle is filled with antifreeze then we can rule out a leak from your engine and look for missing fender splash guards/ or broken wiper cowl by the windshield or a missing lower engine cover water can be getting in from carwashes/rain so you have to do a little looking around or get someone to help you ////either way your engine should be misfiring running rough and check engine light is on ////when you say oily water do you mean just water with a slick on it(outside water getting in) sort of how salad dressing looks or is it a mustard looking color?(engine leaking antifreeze)if it's just a slick get someone to pull the spark plugs use a sweat sick and a long screw driver to clean the plug Chambers where the plug screws in use carb/fuel injection cleaner on all wet cylinders and leave the plugs out so it can dry up inside the cylinders for about 2hours the cleaner will mix with and help dry up the water examine the spark plugs and the wires boots or coil on plug boots to make sure they are not burned through and dry if burned replace them after this process is complete start the engine and observe the running condition for about a half hour if no water is present then we know it's coming from rain,carwashes and something is missing letting the water in go to rock auto.com and look up your car (body section inner fender splash shields)(engine section cover)for pictures so you can see what your looking for if you are running your engine with water and you find water after cleaning depending on what cylinders it's in possible cracked head///blown out head gasket if the water is in the combustion Chambers under the plugs but not on top where the plugs screw in ///either a cracked block or head gasket is the car steaming smoke from the exhaust if so then big problems if not the you are still leaking water into the system a loose hose clamp bad thermostat gasket or a broken hose or pipe leading to the heater core please write done everything you have done for me and post back with precise info and I will do the best I can to help you obviously I'm not there so you have to think carefully about what you say in your post do not be vague because we will never be able to get to the problems cause good luck Stephen

If you unplug the injector does it stop dumping fuel? If that is the case the ground circuit is always grounded, if it stills dumps then the injector is stuck open.

If it has the 3400 v6, better known as the 3.4litre, this motor was prone to head gasket failures. Antifreeze on spark plugs is a sign of head gasket failure, so is antifreeze in the oil. Have a mechanic put a dye in the cooling system that is detected with a certain light and that will tell you exactly where it's coming from. Headgasket repair is not cheap. May be easier and cheaper to replace the motor. Wish you the best!

VW Golf mk4 1.4 16V, m.y. 2000
The spark plugs are placed under engine cover. See the picture below:

All I am getting from your discription, is that you
have a code & a misfire ,you have yet to diagnose.

Except for replacing the wires, that should last the life
of the car,your doing okey

You now are embarking on throwing parts at it,
not diagnosing.

I can't tell you how to continue,as I don't know
if have any test equip or skills required.

You may have a bad ignition module or other
issues

Again,test,don't install 1 part,unless something
tests bad.

You need to remove the air box on top of the engine to get access, then pull the ignition leads up and out of the sleeve. You will need a deep 14mm 3/8 drive socket and long extension ( the sleeve is 20mm wide and the socket from halfords just fits ) to unscrew the plug and then a magnet on a stick to retrieve the spark plug

P0300 Random Misfire

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.

A Random Misfire code usually indicates a vacuum leak or bad gas.

NOTE: If a misfire in a specific cylinder should lead you to check the spark plug, fuel injector and compression.

ignition coil pack

look up by the fuel rails and you see these funny looking things normally they have two wires on them and the spark plugs are under those and in most cases you have to remove the fuel injecter rails in order to get access to the plugs