Don Foster gave these great audio diagnostic criteria:

„h Injector noise is a ticking sound.
„h Valve noise is a clicking sound.
„h Piston slap is a light tapping sound.
„h Rod knock is a deeper hammering sound.

Our new 240 sounds kinda like a sewing machine. Is this a clicking sound of a valve noise? If so, does it just need a valve adjustment?

Thanks.

The B230F is a rather noisy engine to begin with. The odd thing is, some are noisier than others, and a few here and there are fairly quiet, save for the injector noise.

By the way... the injectors all fire at one time, so isolating the noisy one is a matter of disconnecting the wire to the injector (but that can set the check engine light, so don't do this if you aren't willing to go through the reset for that). Some injectors are louder than others in different cars, so that can be part of it.

Valve noise is a potential issue. It can be loud but it is better to be on the loose side on a valve adjustment, than to be on the tight side. In other words, you could find adjustment needed, but more than likely you will find that there is no adjustment needed.

Other ticking sounds can be produced from bad valve absorbers (very common -- requires camshaft removal to repair) and a bad exhaust manifold gasket.

By the way... the injectors all fire at one time, so isolating the noisy one is a matter of disconnecting the wire to the injector



Is that really true? Surely they have to inject at the right point in the cycle for each cylinder?

Nope. You can swap wires on the B230. The vaporized fuel gets injected into the manifold and waits momentarily until the intake valve sucks it in.

Yours sounds just like mine. I call it a Singer sewing machine.

Don left out another noise, which I think is the one you are describing. All fuel injection engines with multi-injectors make a kind of pneumatic sound, obviously the noise of each injector in turn pumping liquid. I think "sewing machine" about describes it - it's perfectly normal.
Unless of course you have multiple valve noise, but that would be louder and much more metalic. Try unscrewing the oil filler cap - any noise inside will get louder.

And if it is "multiple valve noise", is it something to worry about? And how would I fix it?

Thanks.

Sorry, I sort of invented a bit of jargon there. What I meant was, noise from more than one valve. If one valve is noisy, say the clearance is too great, you'd get a rythmic tapping sound. If several valves had large clearances it would be more like a noisy sewing machine. It doesn't really matter, just means the engine won't be running at peak efficiency, and you'll have the noise. As I say, if the valves are tapping it gets louder when you unscrew the filler cap.
For peace of mind, or curiosity, I'd check the clearances some time. But from your description I'd say you are just hearing the ordinary noises that are quite normal.