Rough Idle goes when N205 disconnected

[MikePottee]

Hi all,
I’ve recently changed my cam chain and tensioner (MK5 GTi AXX) due to a diesel like noise when warm. The noise has gone but I now have a slightly rough idle when warm. When I disconnect the N205 valve the engine smooths out and only the injector and HPFP tick can be heard. Essentially disconnecting the valve when hot seems to make the car sound like it should and as it does cold.

With the valve connected the noise does go with a little throttle. When the engine settles it can be a random amount of time and the rough idle returns.

I’m thinking it could just be a bad N205? Before I changed the chain and tensioner I did have a P000A code and have had one since. When the idle is rough I have no codes at all.

Has anyone had a similar experience?

Thanks
Mike

[LC5F]

If you are confident your timing has not changed, it could be one of the ceramic seals in the Camshaft Adjuster Housing has broken, they get brittle with age - and quite often in YT films and online "how to's" they don't get a mention of how easy they are to break when removing/installing the cover.

Genuine ones painfully are over £40 a set of 3 - But I have just installed these on mine - so far so good:https://www.ebay.co.uk/itm/333932651192

I found it easiest to wind them around the shaft with oil or engine lube, gently pulling them open to pass any ridges - installing the top one makes it easier to get the second one over... you will see when you get there.