Help Please CDUC Timing Chain Tensioner

[Blue46]

I own a 2014 3.0tdi with the 245bhp CDUC engine. It currently has approx 73k miles.

Occasionally I'm getting a slight rattle/clatter on startup from cold (sometimes warm if left long enough) that lasts 1-2 seconds. Engine sounds smooth after and drives fine.

I've read that this noise is extremely common and nothing to worry about, unless it lasts more than a few seconds. I've also read that Audi have a revised tensioner designed to fix this issue.

My question is, do I need to look at replacing the top tensioner with the revised one asap or is there nothing to worry about? I've been given an estimate of about £550 to replace the tensioner in situ.

Thank you

 

[pelhamsdetailing]

The rattle when cold is due to no oil pressure in the tensioner. When cooling down it slowly decreases in pressure, which you then experience, if enough time has passed, chain rattle.

I have no knowledge of non-revised and revised tensioners, so i wont speak on that. My 2007 3.0TDI CAPA had the briefest of rattles at 127k on cold startup, and have read of other owners only ever experiencing this, some with more, less or similar mileage. If it has only started doing it and you want to keep the car in the long run, it may be a worthy investment for the long term, but it is also a normal thing to experience with these engines at such mileage. If it became excessive, like 4-5 seconds, or even permanent, then the tensioners would need changing - chain too, just because you're there with an engine out on the floor anyway

If it brings you comfort and the garage can be trusted they've reliably identified it to be that specific tensioner, then do what feels right for you.

 

[ninjag]

If it's part number 059 109 507 K then the 'K' modification code could suggest a change in design, material or vendor, but it can also mean it's just a different version of this base part. It can also have been modified before manufacturing and therefore get the code.