MK1 Octavia VRS

Hi guys,

I'm new to this site so bare with me.

I own a mk1 octavia vrs and having a little trouble lately.

I work in a VW main dealer garage and have nearly finished my apprentaship now, so take note that I have full access to the VAG equipment and diagnostic tools and also that I do know may way around a car very well, especially my own.

My problem is that last weekend on my 1.8T (AUQ 132kw) VRS I replaced the cam chain tensioner/adjuster, cam chain and all relevent gaskets as the chain was starting to rattle from cold start ups (as they all do) so I went to the expense and hassle of replacing it.

Everything I replaced was with main dealer parts, although I did buy the tensioner on ebay. But it is still none the less a genuine VW/Audi part, just being old new stock. I bought it for €130, as in work it would have been €550 or there abouts! (Trying to save a few pound)

Since doing the chain the car is still running perfectly as it was before hand but every few days I'm getting the fault P0012 for having over-retarded timing. This is confusing me as I have double and triple checked all my timing marks and they are all 100%.

For the chain side of the cams I followed the marks on the cams and caps and also counted my 16 rollers on the chain.

On the timing belt side I used the mark on the cam pulley and rocker cover, and also the flywheel as it is more accurate than the crank pulley and cover. So my timing is checking out perfect and the car runs sweetly but every few days after deleting the fault it returns and brings the engine management light on again.

I'm not to worried on the mechanical side of things and this fault obviously isn't to serious as it only brings my engine light on after noting the fault about 10 times (I would estimate). But none the less I cannot see why it is coming on. I've checked TPI's and checked for software updates all to find nothing at every turn. The technicians in work also seem to have no idea what the problem is but they're leaning towards a dodgy chain tensioner but I can't see how that is plus I don't want to go to the time and expense of replacing it all over again, but I will if it can be proven that is the problem.

So my question is this, has anyone had this problem before and can you please help me??

Regards Joe.