fuel leak location
 

I finally had the chance narrowing down my fuel leak. Took me while but I found the source. Have no idea what this part is so I might need to pick your brain. Elsewise I have to go down and browse thru the repair manual.

The leak seem on or around this part. It has a flat bottom and from there the fuel is dripping onto the starter motor and then onto the differential.

This is from the distance so you can see the rough location in the engine bay

https://www.ausjeepoffroad.com/forum...e540dbc8d5.jpg

And this is zoomed in

https://www.ausjeepoffroad.com/forum...e548122c7c.jpg

I just hope it is one of the areas where I have to replace the O-Rings for the fuel line.

It looks like the motor for the swirl flaps to me. The spindles that turn the flaps (much like a throttle flap in a carbie) are connected by small arms to the swirl motor. There are o ring type seals around the spindles wear and leak oil . Have you disabled the EGR and swirl flaps?

Thanks for the reply. No I have not. Should I and is there an instruction somewhere. I looked online but found only WK EGR elimination instructions.

Search the forum, it's here somewhere :D

Flaps disable: 4.7kohm resistor between signal pin and ground I think

Yes search this forum for the details. EGR is a separate mod to SWIRL FLAPS. Both are pretty simple and involve a simple circuit. As AdrianD has pointed out swirl is very simple,just cut the 3 wires to the swirl motor and a 4.7k ohm resistor from signal wire to ground on the wiring loom.
I only asked because the leak could just be oil leaking down from the swirl shafts...this is what happened to my crd 2.7. I removed the manifold and cleaned all of the terrible crap out of the choked up manifold (a VERY dirty job...dont attempt it unless you really want to clean it).While it was off the brittle swirl flaps and shafts removed,and holes plugged. There was a nice performance increase after it was done, and the oil is much much cleaner after 10,000km after EGR delete.
Do both at you own risk , they are probably against the EPA regulations.
By the way before removal of the manifold, several cans of so called manifold cleaner were used. Once it was off it was obvious that this cleaner did stuff all. It also took a long time with the pressure washer and solvents to get the muck out...so a magic can of cleaner had no hope.

I confirm this is the swirl flaps actuator, the grease and junk you see around it is probably coming from the swirl flaps seals under the intake manifold. The linkage between my swirl flaps actuator and swirl flaps linkage fell down when installing motor mounts (I'm 100% sure was already brken and got stuck somewhere around motor mount), so I guess my new mod is to do the swirl flaps delete mod, clean intake and delete the EGR. Also bought a catch can so no more dirty intake, hurray.

If you suspect having a fuel leak, the symptoms are hard to start car when cold (after hours of engine off) or visible bubbles on fuel lines. The fuel hose orings rot over time and end up leaking air inside. Also, the GC 2.7CRD which has the OM612 engine doesn't have an electric pump on the fuel tank, it has a low pressure pump and high pressure pump at the front top of the engine (black triangle shapped piece is the high pressure, small rectangle shaped piece that connects with it is the low pressure). The low pressure fuel pump sucks fuel from the fuel tank. Fuel isn't pumped before ignition, so is there's any air leaks in the system the fuel will go back to the fuel tank, when cranking the engine the low pressure pump has to suck all the air between the pumps and fuel tank first before any fuel pressure is reached in the common rail.

Other less common leaks can be the fuel pump gaskets or fuel filter orings.

I would buy the OEM orings from Mercedes and replace all of them (6 if I remember right). I ended up replacing the 3 hoses but was a pain in the arse, although not a complicated job but you need to remove some stuff to do so. New orings should do the trick. It fixed my long cranks in the morning, it now takes like 2 seconds to fire.

Now that I look at it, your filter is a bit weird. Mine has total of three hoses at the top and one drain plug. One conects to the fuel tank, second to the low pressure pump, third to the return line from the common rail (I think) that is connected to a valve that sits on top, when temperature is exceeded it returns fuel back to the fuel tank, otherwise it returns it back to the fuel filter.

https://www.ausjeepoffroad.com/forum...88e2a76c83.jpg

The fuel filter also has a hole at the bottom where the water in fuel sensor sits.