Hey guys, been a long time since I posted so go easy.

I replaced my timing belt on Thanksgiving 2007, using mostly information from AW and the Bentley. I had the cam-lock bar but not the crank lock pin (keeps the crankshaft at TDC). There were a few critical bits of advice that I didn't follow but the job went ok, with a little help I was all done in a total of about 12 hours between 2 days, just taking my time. Put 8,000 miles on the car since then, two long road trips, and no problems.

Last week I had the bumper off for some work on the wiring of one of the electric fans, and I must have gotten a piece of junk into the timing belt area -

result was when I started the car I got a CEL and the code was Camshaft positioner to crankshaft position sensor mis-match (something like that). The drive gear on the TB (behind harmonic dampener) had jumped at least one tooth. The car still ran but not happily. This weekend I tackled the re-timing and went by the book but realized that it is a different procedure than just replacing the timing belt and I did it wrong. I locked the crank into position (this time with the right tool) but realized I would not be able to line up the cams because they looked like this with the crank at TDC:

<img src="http://pictureposter.audiworld.com/86005/re-timing_low-res_3.jpg">

This is not the way it should go. I ended up de-tensioning and removing the belt, and the valve spring pressure on Bank 1 (pass) turned the cam about 60 degrees until one of the pistons stopped it. I don't know what if any damage this has caused. If anyone has to fix timing that is only a tooth or so off, this - follow the Bentley procedure with the exception that you should not put the crank lock pin in until you have removed the timing belt, popped the cam sprockets and re-installed them and have the cam lock bar back on. Until then be careful not to move the crankshaft, and don't line it up with TDC until you have the cam bar on. If that is not clear let me know.

A couple other notes: I thought pre-tensioning the belt was just a style point before now, but you can definitely see the difference in cam sprocket position when they have been popped off and the belt is being tensioned. This is how you get your timing off by "less than a tooth" = yes that is possible.

In any case the timing is good now, but I have a mysterious misfire only on cyl 2 now that comes and goes, don't know if it is mechanical damage from the cam trying to spin or a loose wire or coilpack. Sorry for the long post, hope this helps someone doing it and feel free to email as my mind is fresh on the details if you have a question -

 

ya ya.. it may be two years later but I have my S4 now. And being such, I'm getting ready to do a tb and everything else very soon. being I just got the car and have no idea when maintenance was done. I'm just going to do it so that my mind is at peace.

I wanted to thank you for this post because it's given me the scenario of something not working out. Thank you for the photo as well. Most definitely helps!!!

and just to clear this up, you do the pre-tensioning of the belt right?
I asked because I'm doing complete seal kit. I mean all of them. Minus the rear main seal. All the cams, the cams tension-er seals, valve cover(that goes without saying doesn't it...), hall sensors seals, and front main seal as it comes with my TB kit. So I'll being removing the cam sprockets completely anyways... along with the cams.

I bought my tools, cam bar, crank pin, and the cam tension-er adjuster tool. I'll be doing the cam adj tension seals the way the book says, only because I'd rather have more than enough room to work with ( and cuz I'm meticulous in any repair I do) than having a serious issue because I couldn't get my finger somewhere do to everything in the way.

(Most of you are thinking why take out the cams.. that's so much more work, yes it is.. but I've done it many times on my sport bike for valve adjustments and it's great peace of mind) Plus it's truly not that hard at all. The book clearly points out everything, plus my previous years experience of doing it that way.

Like I said, it's peace of mind.

 

dot do as i did bank 1 has bend valves if you get tired dont keep working on it...
now looking for cylinder head (loool)
be extra careful and mark MARK everything u see moving (not like i diid)

 

JHMotorsports sells a DVD for about $30 that shows a TB job being done if you want something to supplement the manual you've got.