Hi everyone, I'm new to the forums and joined as a last-ditch effort to try to figure out what has happened to my car.

It's a 2006 A4 with the 2.0L turbo, automatic, 51595 miles, all oil changes kept up with dealer. Last oil change was in April of 2011 at 42k miles. After some reading online I realized that it may be a better idea to replace oil before every 10k miles, but I don't think that's the problem at this point.

My car died last week while stopped at a red light, as the battery light lit up red. I tried starting it again but could not; it's making a pretty terrible sound that gets deeper the longer I try. I had it towed to a mechanic on my roadside assistance plan who said that he couldn't figure out the exact problem without tearing into the car yet, but he did a compression test and the numbers for each of the four cylinders were 0 PSI, 10 PSI, 25 PSI, and 0 PSI. Not good. He said my timing belt looked fine, and that the 2.0L engine (from VW) just entered a recall due to the fuel pump. So with that he advised me to take it to an authorized Audi dealership so that they can replace it at no cost if it is a recall-related issue. I had the car towed there last Thursday, 6 days ago.

I called today and apparently they still cannot figure out the problem after taking the valve covers off. Hurriedly the tech told me that the some of the valve heads have been bent from some sort of mistiming between the camshaft and the timing belt **** I had to look all of that up since I am not very engine-savvy. Again, I was told my timing belt looks to be fine. There appears to be a problem with the camshaft. Either it is not turning, or it is not turning correctly, or something else. The first mechanic thought maybe the fuel pump could have damaged the camshaft but the Audi dealership doesn't think anything is wrong with the fuel pump, unfortunately. He is going to call me back later today with some pricing/repair options and let me decide.

My question is, at what point does this car become a lost cause? I don't want to authorize some unknown number of hours for them to work on it and not find out the cause, and I don't want to replace the entire engine if it's something that can be fixed. And after reading some of the forums my very unprofessional opinion is that it might be carbon buildup, as it's seemed to have trouble with cold starts (but never failed to start). Does anyone have an opinion on what the problem could be? How much money would any of you put into this before deciding it's not worth it any more? $4k? $6k? 10k?

I'm moving in a month and I can't leave it here. Fortunately my parents live close enough and have loaned me a car.

Thanks everyone for taking the time to read this and offer any advice. I'll try to provide any information you like.