On 12/22, we bought a 2014 LaCrosse with 26K miles from Carmax. On 1/1, the push-button start froze and left the car in accessory mode (heater and radio on), which killed the battery in about three hours. After a jump start, we took it to our mechanic, who diagnosed a starting system short and some low-voltage problems. Carmax technicians replaced the battery and said the electronic system was rebooted and all codes were clear, and the car hasn't had the same problem since. A week later, however, the service engine light came on, and Carmax had to replace the oil pressure control valve. All of this has been covered under the 30-day full warranty, but we're now almost out of that. We have a full-service extended warranty with a $300 deductible but worry that we might have gotten a lemon and are considering going back to Carmax and trying to negotiate a turn-in deal on another car. Have any of you had similar experiences with such a relatively new LaCrosse? Thanks for any advice.

 

Nothing yet, we have had our '16 almost 2 years now with no issues at all. Think we're still not even at 6K miles yet. Never heard of oil pressure control valve, not saying they don't exist though. See if I can find something about that? http://www.vw-resource.com/oiling_system.html Yup, and they've been around awhile (shows for VW but principle must be similiar). Interesting, I did know of pressure relief bypass in oil filters. Will have to ask on the Boss 302 Forum about those.

Oh forgot, hard to say if car is a lemon. But imagine all problems would be in the OBD history (they're the automotive Black Box). Know you can clear codes but seems a chronological list of events should be available also for review. Can even assist to reconstruct accidents with/from those is my understanding. Features: https://en.m.wikipedia.org/wiki/On-board_diagnostics

Con't.- I tried to locate the control valve for a Boss Mustang Roadrunner engine and turbochargers come up. Probably for the wastegate valves they use. Also put post on forum to see what is known about such. This is the best post to date, have picked up on something I knew nothing of.