340i engine noise question
Discussion
Hi all,
Last summer I bought a 340i M-Sport touring AUC, great spec and I love the car.
One thing that does concern me a bit though is a noise I can hear when the engine is under moderate to high load, say from approx 2k rpm with throttle > 50% open.
I don't know whether to describe it as clicking/ticking/chirping noise but it's certainly not a sound I was expecting to hear and is a little disappointing given how smooth I was expecting an i6 to be.
It's fairly subtle and doesn't seem to change pitch or tone with increasing revs or load. Probably best described as a sound like a crinkly sweet wrapper!
At higher engine revs it gets completely drowned out by the engine/exhaust note, but is clearly audible to me at lower RPM when put under load.
It's under manufacturers warranty until March and the remainder of the AUC warranty until June.
Had it in to the dealership for investigation and after an extended test drive they reported the sound was injector noise and was normal, however I don't recall hearing the sound from another 340i I test drove. Injector noise does sound reasonable given the pressure they operate at but I'm keen to get some thoughts from others who have the B58 engine and if this is a 'characteristic' or something more problematic.
I've tried various fuels ranging from 95-99 octane and this doesn't appear to make any difference.
Certainly isn't impacting economy or performance in any way!
Thanks all!
Last summer I bought a 340i M-Sport touring AUC, great spec and I love the car.
One thing that does concern me a bit though is a noise I can hear when the engine is under moderate to high load, say from approx 2k rpm with throttle > 50% open.
I don't know whether to describe it as clicking/ticking/chirping noise but it's certainly not a sound I was expecting to hear and is a little disappointing given how smooth I was expecting an i6 to be.
It's fairly subtle and doesn't seem to change pitch or tone with increasing revs or load. Probably best described as a sound like a crinkly sweet wrapper!
At higher engine revs it gets completely drowned out by the engine/exhaust note, but is clearly audible to me at lower RPM when put under load.
It's under manufacturers warranty until March and the remainder of the AUC warranty until June.
Had it in to the dealership for investigation and after an extended test drive they reported the sound was injector noise and was normal, however I don't recall hearing the sound from another 340i I test drove. Injector noise does sound reasonable given the pressure they operate at but I'm keen to get some thoughts from others who have the B58 engine and if this is a 'characteristic' or something more problematic.
I've tried various fuels ranging from 95-99 octane and this doesn't appear to make any difference.
Certainly isn't impacting economy or performance in any way!
Thanks all!
Not a 340, but you get a similar noise in the 140 too. I noticed it when I got mine & it seems to be a characteristic of the engine. Used to really bug me at first, but you do get used to it.
Thread about it here on babybmw:https://www.babybmw.net/forum/viewtopic.php?f=74&t=90209&start=30
Thread about it here on babybmw:https://www.babybmw.net/forum/viewtopic.php?f=74&t=90209&start=30
My 140i has always has a somewhat similar noise- perhaps not "crinkly" but definitely pronounced in similar load conditions to those you describe. Always more noticeable in hot weather. However it's pitch does vary with engine speed.
Goes away when I turn off the climate control, so I suspect it's the magnetic clutch for the compressor. Have you tried turning off the climate and seeing if you still get it?
Goes away when I turn off the climate control, so I suspect it's the magnetic clutch for the compressor. Have you tried turning off the climate and seeing if you still get it?
Is it road speed or engine speed related? Are you sure you do not have a dried out leaf somewhere in the air-vent system? That was a regular issue with my old E36. Unless I was scrupulously diligent in removing fallen leaves from the windshield lower grille, they would dry and get in, then dry more and flutter. They would eventually desiccate further and go away.
On a separate issue, I had a slight knock on my 335d, at light throttle openings. It made it sound, well, annoyingly like a sort of quiet diesel! BP ultimate diesel got rid of that for me, now I have reverted to Shell. I know yours is petrol, but have you tried all variations of petrol brands available?
On a separate issue, I had a slight knock on my 335d, at light throttle openings. It made it sound, well, annoyingly like a sort of quiet diesel! BP ultimate diesel got rid of that for me, now I have reverted to Shell. I know yours is petrol, but have you tried all variations of petrol brands available?
Cheers for all the responses all! I posted the same thread on F30 post too and have had a similar mix of replies (some do, some don't make the sound).
I must say that it's especially noticeable at the moment, not sure whether it's the cold or the 95 RON BP fuel I'm using this tank. I've try exclusively running V Power for a few tankfuls to see if that changes how audible it is...
I must say that it's especially noticeable at the moment, not sure whether it's the cold or the 95 RON BP fuel I'm using this tank. I've try exclusively running V Power for a few tankfuls to see if that changes how audible it is...
Pica-Pica said:
Is it road speed or engine speed related? Are you sure you do not have a dried out leaf somewhere in the air-vent system? That was a regular issue with my old E36. Unless I was scrupulously diligent in removing fallen leaves from the windshield lower grille, they would dry and get in, then dry more and flutter. They would eventually desiccate further and go away.
On a separate issue, I had a slight knock on my 335d, at light throttle openings. It made it sound, well, annoyingly like a sort of quiet diesel! BP ultimate diesel got rid of that for me, now I have reverted to Shell. I know yours is petrol, but have you tried all variations of petrol brands available?
Good thought! Sadly it does seem directly related to engine load and the sound completely disappears when I lift off. Cruising at 70 with constant light load is whisper quiet. Loading the engine up from low RPM with wide throttle I hear it straight away.On a separate issue, I had a slight knock on my 335d, at light throttle openings. It made it sound, well, annoyingly like a sort of quiet diesel! BP ultimate diesel got rid of that for me, now I have reverted to Shell. I know yours is petrol, but have you tried all variations of petrol brands available?
Gassing Station | BMW General | Top of Page | What's New | My Stuff