Do injectors make a noise?

[CCCMikey]

I've noticed for a few years that there's a sort of knuckly knocking sound from my car when idling. Nothing particularly loud, but I put it down to ageing and cold weather.

Since repairing the LPG injection system after almost a years' down time, I've noticed that the sound disappears completely when on LPG, and is immediately there again when I switch it back to petrol. Does that mean injectors make a noise? Or is there some subtle difference between how the two fuels burn?

 

[VS 5.0]

Yes they do, but not a knuckly knocking sound in my experience.

 

[wildfiremaint]

More a faint tickatickatick
sound
It would be reasonable to assume
that when you switch to LPG and the the sound stops that it was the injectors being the cause.
Cheers.

 

[CCCMikey]

Righto - just an old car mystery then! I'll try to record it one day.

Thanks for your replies.

 

[gohrdrgomad]

I've noticed for a few years that there's a sort of knuckly knocking sound from my car when idling. Nothing particularly loud, but I put it down to ageing and cold weather.

Since repairing the LPG injection system after almost a years' down time, I've noticed that the sound disappears completely when on LPG, and is immediately there again when I switch it back to petrol. Does that mean injectors make a noise? Or is there some subtle difference between how the two fuels burn?

lnjecters can become loud in my experience when dirty. A tuned spitting noise is made on operation and if you turn the ignition on you should hear them spit a few times to prime the combustion chambers, not like a tap as the lifters make when priming. Knuckling knocking at idle sounds like a lifter discription to me and could be oil related and rectified depending on some factors. Regular oil changes 5-7000 with a correct/quality oil will assist.