S211E220CDI Loud Whining Noise From Fuel Pipe Near Rail on Turning Key

Page may contain affiliate links. Please see terms for details.

Nigos

New Member
Joined
Jan 13, 2016
Messages
7
Car
W211 E220 CDI avantgarde estate
As the title would suggest I have a fairly loud noise coming from some fuel pipes near the Injector rail. It lasts for about 25 Seconds after turning the key (not starting the engine). I don't know whether it is related but when the engine is cold it takes a little longer than usual for the engine to get going as though it is not initially getting the fuel it needs.

The video below shows the problem. The area at the 12 second mark is where most of the noise and vibration is apparent.


Any help would be appreciated as most of the components involved are expensive!
 
Sounds like air being purged from the fuel system.
If you wait for the noise to stop, when the fuel pressure is up, does the engine start as normal ?
You have an air leak that allows the fuel to drain back to the tank when the lift-pump is off.
 
Sounds like air being purged from the fuel system.
If you wait for the noise to stop, when the fuel pressure is up, does the engine start as normal ?
You have an air leak that allows the fuel to drain back to the tank when the lift-pump is off.
It is still a little hesitant initially on the first start and hunts a bit for the first 10 seconds or so. On subsequent starts it fires up fine. It makes this noise every time you turn the key though regardless of whether the engine has just been running or not.

When you say "lift-pump" I assume that is the in tank pump?
 
When you say "lift-pump" I assume that is the in tank pump?
Yes, but I would look for a leak at the engine end. Perhaps the connections to the fuel filter ?
There is a discoloration on the LH pipe where it enters the filter canister.
 
Yes, but I would look for a leak at the engine end. Perhaps the connections to the fuel filter ?
There is a discoloration on the LH pipe where it enters the filter canister.
Thanks, I will have a look. Now you mention it, it does seem likely to be an air leak. I will report back when I've had a chance to investigate.
 

Users who are viewing this thread

Back
Top Bottom