I would like some clarification if possible regarding a loud rattle snake noise at 1200 RPM to 3000 RPM on my 2011 2.0 petrol Octavia VRS which iv'e had since new. It's gradually got louder as the months have progressed and its been on the ramp to look underneath for a loose heat shield or something but nothing. The noise sounds like its coming from the back of the engine somewhere so when my neighbor popped his head out (who works for BMW) when i had the bonnet up he said that's injector noise and its normal... considering he has over 20 years servicing experience I don't doubt what he is saying but has anyone else got or had this issue? This is a brand new engine (20k) old replaced by City Skoda October last year due to a seized chain tensioner. My old engine had done 76k with no noise what so ever and run like a dream. I have used some redex over the last few fills with no real change. City Skoda which I know no longer trades but I am supposed to have a 5 year warranty on this engine so is it worth taking it to another Skoda group and will they charge? For now I will just have to keep the music turned up but that's not a bad thing. 

You may have to record it. No rattle snakes under my bonnet. But I haven't taken it to Texas yet!

 

The injector noise I'm aware of cycles in and out and is a very prominent rapid tap tap tap. You can hear it on other EA888 cars including Mk6 GTis and Audi Q5 Petrols..

The other thing that comes to mind is a loose fitting on the engine / undertray etc.. The turbo heatshield at the back of the engine (against firewall) may be worth a look. You have to remove the intake pipework to get to it. There is a 6mm allen key and 2xM10 Spline from memory. You could just tap and see it it resonates before trying to tighten up or remove and refitting. 

Could it be you need the wastegate actuator clip?

Could be, but that is quite ad distinct rattly sound, which for me was very noticebale between about 2500 and 3000 rpm under hard throttle.  Is at the back of the engine on turbo though.

 

For the OP,  there are some You tube vids of the wastegate rattle sound on Mk6 GTIs amongst others. Although, the car is stationary on the ones I saw, so the sound will be a bit different in motion and inside car cw outside.

Edited 8 August, 20178 yr by TheClient

Thanks guys but nothing suggested is causing the noise so I took it to my local VAG group independent garage. After a good 5 minutes of listening to this sound resonating around my engine we both come to the conclusion its coming from the chain area. Remember this is a new engine fitted only last year from what was a seized chain tensioner so I did not expect this rattle to be from there. I booked it into Skoda this morning to investigate and on my arrival to the car park a service chap come out and said "that's a nice noise" and when I popped the bonnet he said straight away "sounds like chain and smirked" i soon wiped the smirk away when I said its a new engine from last year from a previous chain issue. I am waiting for the call now to tell me what the situation is but one hopes its covered by the repair warranty. When my tensioner seized last year I have no warning, it just wouldn't fire on start up as if it was plugs or coils.