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

New video by Andras Polus

photos.app.goo.gl

 

[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

 

[255/85]

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

I listened to the entire length of the fuel rail including the HPFP and the connections to the rail but, to answer your question, I have not listened to the far opposite end directly. I will do so when I get a chance (or perhaps someone else can do it @Jean Mercier) but I am traveling for the next few days.

It is always possible that the rail is resonating with some other mechanical action and amplifying the sound.

 

[Jean Mercier]

I listened to the entire length of the fuel rail including the HPFP and the connections to the rail but, to answer your question, I have not listened to the far opposite end directly. I will do so when I get a chance (or perhaps someone else can do it @Jean Mercier) but I am traveling for the next few days.

It is always possible that the rail is resonating with some other mechanical action and amplifying the sound.

I never noticed a ticking sound, but OK, as you are teasing me (don't know if that's the right word to use in this situation) and perhaps tomorrow I have some time to listen to my motor. I didn't use the car the last days: the weather was humid but not raining therefore I did a lot of necessary movements with my (not electrical), in total probably some 100 km the last 3 days

 

[Jean Mercier]

I listened to the entire length of the fuel rail including the HPFP and the connections to the rail but, to answer your question, I have not listened to the far opposite end directly. I will do so when I get a chance (or perhaps someone else can do it @Jean Mercier) but I am traveling for the next few days.

It is always possible that the rail is resonating with some other mechanical action and amplifying the sound.

I made a video of the 'thicking noise" this morning. I started filming with a cold motor.
Outside temperature was about 7°C, and I stopped the movie, once the rpm (revolution per minute) dropped to a steady level.

 

[HereinDaRockies]

I made a video of the 'thicking noise" this morning. I started filming with a cold motor.
Outside temperature was about 7°C, and I stopped the movie, once the rpm (revolution per minute) dropped to a steady level.

Yep mine sounds like that

View: https://youtube.com/shorts/E85JAYQLN-8?si=0RTfON1oOuV56F6f

 

[255/85]

I made a video of the 'thicking noise" this morning. I started filming with a cold motor.
Outside temperature was about 7°C, and I stopped the movie, once the rpm (revolution per minute) dropped to a steady level.

No, I wasn't teasing you. I just thought you might accommodate @AWo for me while I was away.

The sound I have named "ticking" is clearly audible in your video. Thanks for recording that.

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

I tried to use my makeshift stethoscope to listen to the posterior end of fuel rail. Unfortunately it is now too short. I forgot that I used several feet of it to fashion protective pieces for some of the cooling lines. Still, I was able to listen to most of the length from the front sensor to within a few centimeters from the rear. On our vehicle the noise grows quieter toward the rear and louder at the front with the loudest point being at the where I previously indicated. I will add that the injector for cylinder no.1 is directly adjacent and could possibly be the source of the sound. Not very scientific I'm afraid.

 

[holdmybeer]

Mine also clatters and ticks noticeably upon startup. Less so when warm.

 

[C-Mack]

Seems to be a characteristic of the B58 family of engines and direct injections engines in general. Looking around various BMW forums and on YT plenty of videos of folks chasing similar clicking/tapping noises. If you consider the incredibly high pressures the fuel system is running at the valves and solenoids controlling the fuel flow have to slam open and shut to control the individual injection pulses there is going to be noise associated with that. Also, the rigid fuel lines will transmit and carry pump and injector noises across the top of the engine and intake manifold.

My Grenadier makes a similar noise and is more noticeable when at cold idle but quiets down when warmed up fully. If it was valve train, crankshaft or piston rod bearings giving up you’d already be on the side of the road with a seized engine. That said, an excessively noisy fuel system is still worth having checked out at the dealer as it’s not unheard of for a HPFP to have issues when you consider the operating pressures they have to work under but most likely everything is running fine.