Hi!
I've a 99 C230K w/ 167,000 miles. Recently, the car simply won't accept gasoline into the tank.
I can add approx 1 U.S. Gallon and that's about.
The fuel will blow back out the filler neck drenching the overflow tube and of course the person pumping the gas.
I have no codes showing on my OBDII reader, have disassembled the filler neck to the gas tank and have not found any think.
Is there a purge or pressure valve somewhere in the system that would cause this?
Thanks,
Ed

 

This seems to be a fairly common issue. Here is a previous thread:

https://mercedesforum.com/m_51035/tm.htm

Hope the link works. If not, do a search "Gas fill"

 

Sleepwalker,
Have you a pictogram or a diagram for the following:

The item replaced was a J cannister vent valve , 000-476-70-32

Thanks,
Ed