RS3 Cold start noise

[Veneeringman]

I'm interested to know if USA RS3 owners with the new DAZA engine are experiencing the 20 sec cold start Rattle/ticking noise ?

Pretty much everyone on the RS3OC and Audi sport net are experiencing it.

I myself have had mine into Audi several times (2nd time they replaced exhaust but it made no difference) Audi then emailed me saying its part of the Advanced Catalyst Warm up phase on the new engine and is normal..........

However I've noticed some anomalies with it.

1) To stop it completely all you need to do is before starting the car cycle around to Dynamic mode first, then press the start button, car starts without the noise, alternatively you can pull back on the stick into 'S' mode which kills the noise too.

2) Some days its not there at all (granted these are few and far between) but it happens on the odd occasion.

3) on my car the noise tends to fade in after 1-2 secs after the starter motor has done, then stops after 20 secs dead, however in the last week or so I've noticed it present the minute the starter turns the engine over, so it almost sounds like a chain rattle if you follow me.

4) there has been a suggestion it could be a waste-gate rattle, however I've held the actuator arm at cold start and even managed to move it, but it makes no difference to the cold start noise.

5) this new engine runs very retarded at start up to aid catalyst warm up plus it employs 5 extra injectors now and 5 exhaust valve solenoids to alter exhaust valve duration, is it feasible a lot of the noise is all these doing their work ?

6) if the car has been stood a while and i start it up, upon gently pressing the accelerator pedal i can hear a 'faint' version of the noise almost like an echo of it, again is this just injector/exhaust valve solenoids working and the noise being resonated into the downpipe ?


I'd be very interested to get USA owners take on it........

[MichiganRS3]

US Spec `18 RS3 - 750 miles - currently waiting for new exhaust delivery & install.

Noticed this cold start rattle / tick yesterday. It definitely sounded like it was coming from the engine bay, not the exhaust valves.

[Veneeringman]

US Spec `18 RS3 - 750 miles - currently waiting for new exhaust delivery & install.

Noticed this cold start rattle / tick yesterday. It definitely sounded like it was coming from the engine bay, not the exhaust valves.

Yep I had that..... they were adamant it was exhaust flaps

Sadly it’s nothing to do with them as my car sounded exactly the same after an exhaust swap.

[Potatohead_RS3]

Audi then emailed me saying its part of the Advanced Catalyst Warm up phase on the new engine and is normal..........

... and that's what it is. The wastegate is held open to warm the converter faster, so it sounds somewhat like an exhaust leak. It is normal cold start operation.

[Veneeringman]

... and that's what it is. The wastegate is held open to warm the converter faster, so it sounds somewhat like an exhaust leak. It is normal cold start operation.

Spoke to a turbo specialist today and he explained the new KKK (BorgWarner) Turbo is waste gate open by default, as the revs rise / load demand increases the waste gate closes to build boost

He did say that he could see no reason why it would rattle unless there was a fault with it, pivot arm bush/sleeve out of tolerance allowing the assembly to vibrate, when i explained about the Catalyst warm up phase he said the 20 sec noise could be resonating from somewhere else in the engine.

[lalalaprise]

Since every RS3 and TTRS does this I'm chalking it up to it being the way Audi engineers intended it to be. Yes, it sounds horrible but it's 20 seconds and goes away.