Petrol/Gas Petrol B58 strange sound at idle

[Andras]

Dear all, I’m proud owner of a petrol Trialmaster with 2500km on the odo. I do have a strange ticking sound from the engine at idle that I find disturbing. Went to the dealer who told me it could be a valve or a solenoid, but no worries it is all ok. Anyone having similar experience/noises?
Thank you, Andras

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[CountyV8]

It's the insanely high pressure of the injection system 350 Bar max (5076.32 psi)

 

[255/85]

So this seems to be where the metallic clink sound emanates from...

At the front end of the BMW fuel rail there's a hexagonal boss and a sensor. On some vehicles the sound is barely noticeable and on some (ours) it can be quite distinct. I've been all over several engines listening to pulleys, belts, injectors, the fuel pump, up and down the valve cover, and as much of the exhaust manifold as I can reach and I only hear the sound right at this spot. Even on one vehicle where my old ears heard nothing when standing in front of the running engine (cover removed) I could still hear the rhythmic "tink-tink-tink" once I put a piece of 3/4" hose (19mm?) up to it. With the cover in place and the hood/bonnet closed it can sound a bit like it's coming from cylinder 1 or 2 through the oil pan. I don't think it is - at least not on our vehicle.

It's probably just as @CountyV8 says - the HPFP is stuffing the rail full of fuel in some manner that we can hear. I could be that it happens just after injector #1 fires which might reduce the pressure briefly followed the pressure spiking upwards again. The sound disappears quickly as RPM rises. Guessing further it may be slight manufacturing tolerances in the rail that require more or less torque being required to line up the sensor connector output with the electrical octopus just below. But hey, what do I know?


edit: I don't know how the thumbs down emoji got into the text.

 

[AWo]

That is the pressure sensor. The valve is on the other side. I could not think why the sensor should make any noise, whereas a valve might make a noise (due to moving parts). Have you checked the other end of the rail for the ticking noise?

AWo