Audi 8p S3 purring noise

[BradyS3Quattro]

Hi,

Has anyone ever heard a purring noise like this coming from the engine bay.



It's only happen at cold idle.
very intermittent.
Any thoughts?

Thanks

 

[dave_beastttt]

That's the sound of the timing chain, the timing chain tensioner is not fully engaging and leaving the chain slacker than it should be, it could be for a few reasons

1. Wrong oil viscosity
2. Oil filter not clicked into oil filter housing correctly during oil change
3. Sump oil pick up pipe blocked or obstructed
4. Timing chain tensioner faulty

 

[BradyS3Quattro]

That's the sound of the timing chain, the timing chain tensioner is not fully engaging and leaving the chain slacker than it should be, it could be for a few reasons

1. Wrong oil viscosity
2. Oil filter not clicked into oil filter housing correctly during oil change
3. Sump oil pick up pipe blocked or obstructed
4. Timing chain tensioner faulty

Many thanks for the reply Dave.
By process of elimination I'd be thinking chain tensioner faulty then.
But there's no error codes and the noise can be heard maybe twice a week.
But I'll get it checked out.
Cheers

 

[dave_beastttt]

Personally, I would think as it's only at cold idle and with the weather being cold, it could be your oil.

 

[BradyS3Quattro]

Personally, I would think as it's only at cold idle and with the weather being cold, it could be your oil.

Running 5W30 Millers Nanodrive EE long life fully synthetic at the moment. (complies VW 504 / 507).
Its done ~6k miles since the last service.
I did have to top up ~1 litre with 5w30 Castrol edge fully synthetic (all I had to spare) though.
The car is now stage 2+ mapped since around ~3K miles ago.
Plan to switch to Millers Nanodrive CFS 5w40 NT+ Fully Synthetic for
the next service due to the map.

 

[BradyS3Quattro]

Hi Dave,

After working through the possible route causes you listed, it seems it is the Timing chain tensioner.
How likely are these to go? Would It be best to leave parked up until I get it is fixed?