Dannyboy2375

Hi everyone 👋

I was wondering if anyone knows the reason behind the oil feed on the fuel rail of any of the m278 vehicles.

We recently did a Injector on a 2013 gl 450 and the seals inside the rail are covered in oil. I see that the valve cover has a hole with a small gasket to allow oil pressure to enter the small galley on the fuel rail.

My question is what is the purpose behind this and what are common symptoms of this system failing.

Thanks!!!!

arsupisemnet

That is not an oil feed. That is non return leak off fuel line, which then evaporated through crankcase vent

Dannyboy2375

That makes more sense than oil.

However like I said when I removed the rail and removed the injector from the rail it's was full of oil.

When i say full of oil i mean the top of the injector was covered and that small passage was completely full of oil as well.

What could cause that to happen?

Thanks again for the reply!

arsupisemnet

The rail was full of oil?

Dannyboy2375

OK so it's kinda hard to explain but the main rail where fuel would be at had no oil in.

Later today I have to take apart another gl450 fuel rail so I'll take pictures of what I find so it's easier to explain what's going on!

arsupisemnet

Your fuel run off line connected to crankcase through small hole in cylinder head cover. Crankcase is positive pressure system. Of course the line would be full of oil and its vapors

rapidoxidation

If it is, check your crankcase ventilation system, There should be a slight vacuum when you take the 710 cover off.