C250D air in fuel

[jools182]

Hi
I have a 1995 C250 D. It recently had a problem with air in the fuel. The guy I bought it from replaced all the plastic fuel lines and o-ring seals. I came to start it yesterday and it just wouldn't. Looked under the bonnet and there was an air bubble in one of the fuel lines. It took about 30 seconds of turning over to get it going.
Any ideas where air could be getting in?

 

[eric242340]

Hi
I have a 1995 C250 D. It recently had a problem with air in the fuel. The guy I bought it from replaced all the plastic fuel lines and o-ring seals. I came to start it yesterday and it just wouldn't. Looked under the bonnet and there was an air bubble in one of the fuel lines. It took about 30 seconds of turning over to get it going.
Any ideas where air could be getting in?

I suggest you start with the fuel filter, check it for sealing. Failing that its probably a pipe connection, make sure they are all tight. Failing that, check all the new seals, one may have been badly fitted

 

[Suki]

There could be several reasons for this.
As a check park the car nose up a hill and vice versa and see if the car starts easier in one direction. This will point to an air lock with certainty.
Also check the auto shut off valve.
This issue has been discussed a lot so have a good dig around on the forum!
Regards

 

[sixpack]

Air in lines

Hi Jools. I had the same problem with last Merc C250D. There is one other O ring between the shut off module and the pump. Take off the black plastic box, held onto side of pump with 2 torx screws. the O ring is on a plastic spigot going into the pump. This cured all my air problems.

Hope this helps



Peter