I took my Explorer in about 1 year ago with a noise underneath when in reverse. Dealership determined PTU issue and fixed. It was still under warranty/ess than 60k. This past week, the vehicle started the same noise, again (now at 89K). Plus, a really bad odor and leaking a fluid (which I forgot to mention to them but figured the tech would find when examining the PTU). I took in and they said that they ran tests and it was "out of time". Out of time? This vehicle runs GREAT! No skipping, stalling... Said vehicle had bad timing and it would cost $900 just to break it down and find the issue. Worst case - $700 parts and another $900 to put it back. Asked them about the PTU issue and they said the tech checked the codes, reset and it wasn't doing it anymore. Desk person told me all this, not the tech. I told them I did not understand how timing and a code could cause issues with the noise/grinding when in reverse. They even said they did not put on the rack. So, I know they didn't even check the PTU and see the leak. It appears the leak is dripping on the exhaust to burn and create that God awful smell. I have decided to take to another ford dealership and see what they say. Not sure if this has been an issue with these vehicles. But, wonder since it was in warranty at the time the fixed the first time and is doing the same thing again, that the previous fix would keep it as a issue that was NOT REALLY fixed. Any suggestions?