Hi, yesterday my fiesta was working fine however today the temp gauge went on red after less than 5 mins driving time and by the time i got back home the engine was making pretty bad smells( i kept driving assumed the gauge was faulty since it was cold and rainy outside).

The engine started to knock and work roughly when strained a bit and had to constantly drop gears where normally it would just keep going (it doesn't feel like its lost power. it just doesn't hold the gear).

When i got out of the car the smell was too much so i opened the bonnet and found oil all over the gearbox side appeared to come out of the power brake pump (or whatever it is)however i m not sure as the whole side including the air filter turbo and inter-cooler are covered in black goo. also the engine was making a hissing sound and it came from the head like something is leaking.

Even if the later problems where caused by the overheating, what could have caused it to overheat that fast?

BTW. it had water when i left home and the oil lamp never came on and it kept on soldiering on, got where i wanted to go and back. now there is not a drop of water and the oil level is very very low

any ideas what the problem might be? the engine is an 1.8l turbo inter-cooler diesel engine (one with the tourqx head bolts)