A few weeks ago my 06 Jetta TDI engine gave out due to cylinder head failure resulted from a worn cam follower. At the time a trusted TDI mechanic estimated the cost of R/R around $5500. It was a bad timing - car was just out of warranty. After a lengthy effort with dealer eventually with VWoA (VW of America), the issue was resolved - VWoA paid all the cost and now the engine runs just like new. I am posting a summary here in hope of providing a reference in case you run into a similar situation.
(the following section is also posted in tdiclub at http://forums.tdiclub.com/showthread.php?t=310550 )
after quite a number of weeks sitting in the dealer's yard, my car finally came back home (yesterday). the cylinder head and cam have been replaced, and the cost, you would ask - are all covered by vwoa as a good will. today i drove it for 200 miles, the engine was smooth, responsive with much more power. i am very happy with the outcome.
1) retain service records. in addition to service/part receipts, log all services in a spreadsheet for each car each time with detailed info like part, brand and model. i have 3 cars, although 2 of them are non-vw, when i submitted my service records, the spreadsheet for all cars really showed that i had been consistently maintaining all cars in a precise way as supposed.
2) promptly report issues to manufacturer. when my tdi was still under warranty, i called vwoa to report heavy black smoke and burning oil issues. in last april right before my warranty ended, i brought my car in for cam lobe check-up, with a uoa showing high metal in the oil, but dealer said no evidence of wear being found. i didn't stop there; i called vwoa to report the issues (and asked the rep to make a note under the vin). this time although my warranty had been out, vwoa was convinced by my car history that the failure had been there but dealer failed to diagnose the problems last year.
3) be nice with dealer service manager and vwoa regional case managers. those people are human beings, they are there to help customers, some of them are really doing whatever they can to help you out if you talk to them in a nice way. i met with dealer service manager only once, talked with him on phone couple times and with vwoa case manager on pone twice. overall, they were very nice and really listened to me.
4) need patience. some times they do need reasonable time to get things done. in my case, the dealer had to contact vwoa for decisions and later they had to order a new cylinder head from out of town (actually it was a re-manufactured head as shown on the receipt).
all in all, the dealer did a good job, i am satisfied.