Purchased a 2005 A4 Audi Cabriolet 1.8T a few months ago, at the time it seemed like a great buy, it had just under 60k miles on it, a new rook, electric, and transmission. The previous owner had all the service records and had pretty much done whatever the his shop told him needed to be done.

Shortly after buying it, it started going through a quart of oil every few hundred miles and vibrating badly at all speeds. The mechanic my girlfriend took it to replaced a turbo and the timing belt and that seemed to solve all the problems.

Then a week ago the oil dipstick funnel cracked and the engine began running very rough at low RPMs (below 1400 or so.) We were on the road and I redneck engineered a seal which kept it from spraying oil all over the engine block. The audi ran fine at highway speeds the whole time.

I took it to the dealership to get inspected and get a new funnel. The dealership in Cary NC claimed that the misfiring was caused by vacuum seal leaks and there were pinhole cracks all through the manifold and crankcase. They wanted to replace all the hoses and vacuum lines for a few thousand dollars but could not tell me which hoses were leaking.

The error codes are for lean fuel/air mix and for misfiring in each of the pistons.

I checked all the vacuum lines with carb cleaner and got nothing.

I cleaned the mass airflow sensor out pretty good and after that it ran fine for about 2 minutes after I started it up then went back to misfiring and vibrating.

I ordered a new MAF and just replaced it but it doesn't make any appreciable difference.

Next I'm going to replace the fuel filter, it's at 63k so I figured it couldn't hurt. Will also replace the engine mounts - they are leaking and both the dealership and the mechanic said they need to be replaced.

Any ideas or tips are greatly appreciated.

Headed out for Afghanistan on Monday and would really love to get my gf's car up and running before I fly.