Hi everyone, I've signed up hoping someone with some 20v knowledge might be able to help!


After a crack developed in my head (2001 AMK S3) I found a suitable recently re built AGU head that I was able to get at a good price to use on my car. I swapped all of the S3 components over to it today and put it all back together but I've lost loads of low down power / torque. It now seems to get going at around 4000rpm and is certainly feeling sluggish compared to before.

I have a feeling it's the cam to cam timing, I triple checked the cam belt timing and I'm certain that is spot on but I wonder if I'm getting confused with the 16 rollers count from exhaust to inlet on the chain.

First off though, when I installed the 3366 tensioner compression tool, the curved nylon type runner was flush with the two prongs that the tensioner tool sits between. Pretty much like in this picture.


After I compressed it and swapped the cams over, the cam notches didn't seem to line up, the ex cam notch was a little towards the back of the head and the inlet notch was a little towards the front of the head. This looked wrong at first but then I realised that the VVT tensioner had only sprung back half way up the prongs so it looked like when it is pressurised, it would rise up and pull the cam notches towards the centre of the head. It seemed to make sense but after a disappointing test drive, I took the valve cover off and the tensioner was still only half way up the prongs.

Could the tensioner be damaged? (I don't think I cranked it too far with the 3366 as I imagine the plastic would have broken on my cheap ebay tool if I tried to wrench it)
Or is the inlet cam a roller out and causing the tensioner to sit lower than before as the incorrect position is causing a cam lobe to be under tension from the valve spring, pulling the chain tighter and pulling the curved part lower?

I'd really appreciate any input as I'm totally lost with this and am dreading the prospect of removing the cams again as taking the tension of the cam belt tensioner on the other side is a nightmare!!

Thanks to any input, sorry for the long post, I should have taken pictures along the way!

- - - Updated - - -

I've just found this, a lucky shot that I took earlier without realising it's usefulness! Obviously in the picture the ex cam isn't at TDC but can you see how if at TDC, the inlet cam notch would be passed the arrow but If the tensioner was all the way up, the inlet cam would pull in to the centre? Maybe at full height the difference is tiny though so it is actually a roller out? The VVT tensioner does fully extend when I turn the cams over by hand but at TDC with this possibly incorrect timing, it pulls the chain tight, pulling the tensioner down.