...All the techs there used improper diagnostics and if what they changed didnt work it was on the the next part, charging the customer accordingly. I work as an automotive/ diesel tech, graduated UTI. Im a firm believer in actually finding the problem rather than trying to throw something at it real quick(even tho I have done that before). Personally it brings me satifaction to know my knowledge figured this problem out.
Being a Diesel Tech you probably know about the Ford 6.0 Turbo Diesel's reputation, unfortunately I needed a dually so I purchased a 2003 F350 with a 6.0 - the first year of that engine. I of all people know you NEVER by ANY first year vehicle if your looking for reliability, but against my own better judgement I did it because I didn't want to spend the extra money on a new truck while I was trying to save money up to start the shop with my Brother. Mistake! I recently read that in the 5 main production years that engine was used in Ford Super Duty Trucks it accounted for something like 80% of ALL warranty claims thru out ALL of Ford, their not talking Ford trucks, their saying 80% of the total warranty claims for EVERY model car, truck, van, crossover, etc that Ford produced!
There's definitely a place and time to start replacing parts, especially when their known to have high failure rates after so many miles and you'll most likely be replacing them in the near future anyways. I did so much research on the 6.0's engine problems as they started happening to me that I started weighing the cost of personally replacing 'known to fail' parts that most likely were causing my problems vs. going to the Dealer and having them plug it in to their computer and start replacing just the parts that it tells them to replace. For example when I started getting fuel injectors failing (out of warranty), Ford wanted to replace the injectors that were bad, I looked at my cost for buying all 8 injectors and replacing them myself (about $2000) and realized I could replace all of them at once for less than what they wanted to replace just the 4 bad ones. In fact for what they wanted to do the job I put in all 8 of the latest generation Ford OEM injectors AND a brand new electronic EGR which was also failing. The same situation when my HPOP (High Pressure Oil Pump) was dieing, I replaced it myself PLUS did the Oil Cooler rebuild AND replaced both of my engines main wiring harnesses (both of which were compromised in known failure points) for about the same cost as what the Dealer wanted for just replacing the HPOP. In my case I knew that the items I was replacing would predictably fail in the near future, and some of the new items were revised to correct their original design flaws, so it was a win/win situation.
At the opposite extreme was a girl I'm friends with, the mechanic her family had gone to forever told her she had (4) bad O2 sensors and a bad EGR and that it was going to cost her upwards of $750 for him to fix everything. I had her bring it to my shop, I scanned it and found she did indeed have all 5 codes, but I knew that the O2's were most likely a result of the EGR or something else having a problem and hopefully all (4) O2's weren't bad at all. Since I don't have any experience with her engine I went on to Google and looked for other people who possibly had that same combination of codes, what I found was that there is a sensor called a DPFE on her engine that goes bad which deals with the EGR, but the problem is it doesn't have a 'tattle tail' function to tell the computer if it's bad or not. Other mechanics had said that sensor is almost always the problem if you have all 5 codes, they also suggested to make sure and buy the Ford OEM one because the aftermarket import ones were junk and would fail quickly. I replaced the DPFE and ALL 5 codes were gone! For a grand total of apx $75 ($15 labor / $60 DPFE) I fixed her car for 10% of what she had been quoted by the other mechanic, plus had he replaced all that other stuff it still wouldn't have fixed the problem and her cost would have been even higher.