(2015 A3 SE 1.6TDI) knocking noise

[a3poop]

Hi guys I have a 2015 A3 SE with 37k miles on it and I keep getting a knocking/rattling noise which carries on from idle until I go for a short (10 - 20min) drive, it seems to come back when I’ve left it idle for a few hours but sometimes it comes back again when i turn the engine on and off, any help would be appreciated

 

[Crash0090]

I assume that you don't actually leave the car idle for "a few hours" never a good idea to leave a car idling for prolonged periods.

what engine do you have?

 

[a3poop]

I assume that you don't actually leave the car idle for "a few hours" never a good idea to leave a car idling for prolonged periods.

what engine do you have?

No not for a few hours my brain wasn’t working when i wrote that i leave it with the engine off for a while and it comes back, I have the cayc engine.

 

[Crash0090]

Diesels love to rattle - mine is no exception lol

when did the problem first start?
have you had any work done recently?
is it worse on cold start?

on cold start my TDI is rattly, but once it warms up it's normally fine.

 

[a3poop]

I assume that you don't actually leave the car idle for "a few hours" never a good idea to leave a car idling for prolonged periods.

what engine do you have?

No not for a few hours my brain wasn’t working when i wrote that i leave it with the engine off for a while and it comes back, I have the cayc engine.

Diesels love to rattle - mine is no exception lol

when did the problem first start?
have you had any work done recently?
is it worse on cold start?

on cold start my TDI is rattly, but once it warms up it's normally fine.

the problem started about 3 months ago, I’ve not had any work done on it and yeah it’s usually worse on a cold start but it doesn’t sound like the usual diesel rattle it sounds unnatural like a knocking/tapping noise.

 

[Crash0090]

can you tell which side of the engine the noise is coming from?

also, if you've got a recording of the sound that would be helpful

 

[Gogo]

Possibly injectors, try different gas station/premium diesel or fuel line cleaner. I notice a big difference switching between gas stations, usually around 2000-3000 RPM, even when engine is hot. Shell V power is worse for injectors sound.