2010 Focus, 1.6 TDCI

Hi all,

I need some advise please, anything.

Last week I decided to replace the thermostat on my 1.6tdci focus, and while doing so, fuel filter kept getting in a way and I decided to unclip the two hoses and move it aside. I also removed the hose that goes across, I think that is vacuum hose?

When I placed everything back, the car started fine, however, (after about one week maybe less) I noticed it gradually needed more cranking to start the engine. And finally, one morning it started and then cut-off... it wouldn't start again even with plenty of cranking.

I figured the air got inside the fuel hoses, so I primed/sucked some fuel out through the green (return) pipe on left side of the engine (a small glass of diesel)... and I managed to start the car again, however it seems the problem is still there, as it is still struggling to start. However, once the car starts, it runs fine.

To makes things more confusing, on the floor I found a small o-ring seal... I service three cars so I can't be sure where it comes from, and I doubt it it comes from oil filter.

I have also noticed, after I switch the car off, there is some buzzing noise just above the injectors area on top of the engine.

Can anyone help me figure out where I've messed up and what to do to figure this out?

Hi,

Which hoses did you disconnect? Was it just that green one? Or did you disconnect the hoses on the filter as well?

There is a small o-ring inside the end if the plastic hoses. However, there are also small o-rings on many oil filters. The 1.6 TDCI filter has a small 'lump' at the bottom with a small o-ring on it. And if you service a diesel VW, the plastic housing has a small o-ring right at the very tip. The coin isn't giving me much scale unfortunately, though the colour is odd. Oil filter o-rings tend to be black, so that one could be from inside a fuel line.

If you want a quick and cheap repair, other members have fitted a non-return valve in the fuel-in line, to prevent fuel draining back to the tank overnight. As these don't use a pressurised system, it'll be very difficult to find a small leak on fuel lines, unless it is as simple as a missing o-ring.

@TomsFocus I disconnected both hoses from fuel filter in order to move it aside. And then In order to suck the air out, I disconnected green hose on the left side of the engine.

I think I will try the non-return valve for now until I manage to find out where the air is getting in.

Add:

If you have an ebay or amazon link to compatible non-return valve it would help.