Wow, you've got the same two gripes I had with mine. For the A/C problem, two things: If you haven't, check the temperature control cable to see if it needs adjustment. You can check here for details on it. Super easy procedure. Also, a few here have insulated their A/C lines and have found some positive results. I, too, thought the Vibes A/C wasn't that competent... And it saw many trips to the shop due to A/C problems but still never was working as good as it could have, or at least as good as I thought it should have.For the engine noise, yep, been there too. I don't recall too many (if any) complaints with the GT engine, there have been a few complaints of noisy base engines, one of those was on the Vibe I had... I never bothered to get anything done to it, the noise developed at about the same mileage you have now and was still there at 74K when I traded. Sounding like a diesel pretty much sums it up. I could have had it fixed for the low, low price of $499 or something though (IIRC) so I decided it wasn't worth it. The procedure is pretty involved for getting the valve clearance back in spec if it is out of whack. Hope you can get everything resolved soon!
03 Vibe base. Born 10/14/2002 06:07 AM
Neptune. Auto, Moon & Tunes, power package. 131k mi.
'13 Sonic LT - 1.4L ECOTEC turbo/6A. 98k mi.
'15 Escape SE - 1.6L EcoBoost, FWD. 47k mi. (hers)