th01

Hi Guys,

I really need a Mercedes wizzard here.

I have a Mercedes W212 E350 CGI with 193.000 km on it. I have owned the car for about a year and since I got it it starts ticking approx. 5 sec. after the engine has been started. I am not talking about chain rattling or something like that. I have located that the fuel hose running to the ( high pressure fuel regulator ) is vibrating/ticking in sync with the unwanted ticking. the only fault code i have is a NOx sensor heater control circuit/open bank 1, and I do not think that is related.

BUT If I remove the electrical connector from the high pressure fuel regulator and then start the engine, then it does not start to tick! It does however show a fault code about fuel rail/system pressure - too high.
If I start the engine and disconnect the connector after it has started to tick then it will continue to tick!

I have uploaded a video here: The ticking starts at approx. 9 sec.

My mechanic suggested that we changed the oil and filter and that we should use 10W60 fully synthetic racing motor oil. We did that but that has not made any change to the ticking..

Also i looked at the fuel pressure at the pump (via obd scanner) and that shows 4,25 bar (probably at idle) and I think that is too low so maybe I should change the fuel filter or fuel pump to get higher pressure.

I hope that somebody can help me with this issue.

Kind regards,
Thomas

CaliBenzDriver

these fuel pumps are astronomically expensive.

th01

Could it be a bad injector?

CaliBenzDriver

take 10mn to listen to each injector one by one then you'll know for sure.