Does this N55 sound OK?

[Rene Artois]

Hello all,

My wife has a 640i coupe. It has been sat not driven for about 2-3 days.
my wife started it this morning and she said it really struggled to start but did in the end but engine was making a loud tapping sound.

She called me out and I switched off the engine and restarted it and it started fine.

However, the engine sounds quite rough. I took a quick video of how it sounds at idle. Engine is completely cold.

https://youtu.be/4VNUlRtPJfE

I welcome your advice and comments.

Thank you

[d_a_n1979]

That sounds really tappety; could it be a sticking lifter at all?

I know these are famed for their noisy injectors; but that sounds more metallic to me!

Have you restarted it since to see if it's calmed off (ie sticking tappet has released etc)?

[Rene Artois]

Thank you.

My wife had to take the car out for a short trip (10-15 minutes). On return, the engine is still sounding exactly the same.

[d_a_n1979]

Rene Artois said:

Thank you.

My wife had to take the car out for a short trip (10-15 minutes). On return, the engine is still sounding exactly the same.

Personally I'd stop using it until you can get someone to look at it properly.

It doesn't sound healthy at all; could be something as simple as a sticking tappet, or it could be worse (chain/guides related etc)

[naturalaspiration]

I do hope oil pressure is ok. You have to read the error codes, hopefully just a valvetronic issue or sticking lifters.

What is the car mileage and how often has the oil been changed? Stop/start in use or coded off?

Edited by naturalaspiration on Sunday 3rd April 14:59

Edited by naturalaspiration on Sunday 3rd April 15:04

Edited by naturalaspiration on Sunday 3rd April 15:40

[anonymous-user]

The engine is quite advanced in that it’s able to adjust valve lash and does not generally present lifter issues. Looking online if it’s at idle and when the car is started up then goes away when driving, it points toward the torque converter.

[Rene Artois]

Hello all

It is 2018 with 37,000 miles. 4 injectors were replaced last year under warranty.
My local BMW dealer had a look and he said it sounds fine and it's just the fuel system.

I am not really sure what to make of that.

Thank you.

[g3org3y]

That's reassuring I suppose?

I would say, it can be v difficult to diagnose issues based on sounds recorded by phone mics. The sound can be so different on where the mic is placed and IME doesn't necessarily accurately portray the sound.

I hope no further issues for you.

[Chamon_Lee]

I had the N55 engine for 2 years and can't say it ever sounded like that. does seem ok. maybe get a second opinion. If they both say its ok then id just roll with it i guess

[Olivergt]

If it sounds different to what it used to sound like, then something has changed!

Is it direct injection? If it is, it could be the injectors, but if it was injectors it should quieten down above idle?

With regards to the dealer saying it sounds ok, maybe ask if they have another car with the same engine that you could listen to?

[naturalaspiration]

I would unplug injectors, one at the time, to try to narrow the issue down. If the engine gets quiet(er) when one injector is unplugged you are one step closer to finding the culprit. Then swap the injector from the noisy cylinder with another one which isn't. If the noise travels with the injector, you need a new one. Not too expensive to source online l, I guess Bosch is the original.

If the noise stays at the same cylinder it may well be bearing damage. Not very likely if the engine was not abused or oil changes skipped.

Edited by naturalaspiration on Monday 11th April 22:22

[liner33]

I have to say it was a shock when i got my first BMW and started it up cold when it was nosed into the garage and in fact the s58 is not a quiet engine either but that doesnt sound right to me , its always hard to tell on a video but id plumb for a second opinion