2.0 tfsi engine knock

**ncp** · 01-11-2008,02:13 AM

Just bought an 05 a3 2.0 tfsi quattro 33000 miles.

Engine sounds smooth when starting from cold but when @ temperature I can here slight tapping at idle only, almost like a deisel. Not sure if this is a valve issue. Driving & at speed engine is sweet as a nut

I Have heard this is a symptom of these engines and is normal however I will get this checked out at the garage. Does anyone else know of this problem?

**motechmike** · 01-11-2008,11:23 AM

If your using poor fuel Try better fuel

Mike

**ncp** · 01-11-2008,12:20 PM

Originally Posted by motechmike

If your using poor fuel Try better fuel

Mike

Thanks Mike
I will try super unleaded next fill up

Neil

**motechmike** · 01-11-2008,12:27 PM

Run the tank ur on now dry then out £5.00 of super in run that dry then a ful tank of super.. On that engine u should run super all the time really

keep us up todate

thanks Mike

**smudger** · 04-11-2008,01:06 PM

Originally Posted by motechmike

Run the tank ur on now dry then out £5.00 of super in run that dry then a ful tank of super.. On that engine u should run super all the time really

keep us up todate

thanks Mike

Just a quick one, I have this noise to and was told by Audi that the sound is normal as its the injectors that make the noise..... how true is this or are they full of it as usual ???? So running it on super should do away with the knocking/tappety sound??

Cheers

**suthers** · 04-11-2008,03:09 PM

i have just come back from audi as my car was knocking in reverse but then stopped when i got there

! Any way seems to have gone now, but i also asked about the engine because it sounded loud and they said that the 2.0T fsi engines are loud... He brought another one out and it sounded the same so im happy!

**smudger** · 04-11-2008,03:57 PM

But is it worth it putting super in it??

**engineermk** · 04-11-2008,05:06 PM

Super unleaded (98 ron) will give more power at Wide open throttle as the engine can advance the spark more until knock occurs. so running super unleaded will improve your acceleration times.

During normal cruising and driving in traffic the effect of super will not be noticed as higher knock rating is less important. Super may give very marginal improvements in fuel consumption but you're not likely to notice it.

I never use super in my 2.0T , its just fine on regular unleaded (95 ron).

Run it on regular 95ron from a branded outlet (shell BP etc) and it will be fine. Steer clear of the supermarket stuff.

**smudger** · 04-11-2008,06:06 PM

Originally Posted by engineermk

Super unleaded (98 ron) will give more power at Wide open throttle as the engine can advance the spark more until knock occurs. so running super unleaded will improve your acceleration times.

During normal cruising and driving in traffic the effect of super will not be noticed as higher knock rating is less important. Super may give very marginal improvements in fuel consumption but you're not likely to notice it.

I never use super in my 2.0T , its just fine on regular unleaded (95 ron).

Run it on regular 95ron from a branded outlet (shell BP etc) and it will be fine. Steer clear of the supermarket stuff.

Cheers for your reply, but surely it don't matter where you get your 95 ron from as it will come from the same refinery regardless if its BP or Tescos.

**engineermk** · 04-11-2008,06:23 PM

Originally Posted by smudger

Cheers for your reply, but surely it don't matter where you get your 95 ron from as it will come from the same refinery regardless if its BP or Tescos.

True, its all from the same refinery but the additives put in at the time the fuel is dropped in to the filling station tanks differ between brands. these additvies help to keep the injectors clean and reduce carbon buildup on the valves etc.

My company tests these additives, i know they make a differnce to the long term condition of the engine. I may use 95RON but i always use branded fuel.