Three problems related to other fuel system have been reported for the 2009 Ford Flex. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2009 Ford Flex based on all problems reported for the 2009 Flex.
The Ford panel near the driver and passenger window continues to come apart. As far as the vehicle's fuel. The first time I was at a gas station. I put gas in my car. I got back in the vehicle and my gauge was still on empty. So I got worried. Then I went to a different gas pump and put more gas in there. I started my car and it was still on empty. I drove around the parking lot to see what would happen and about 2 minutes later my gas gauge was 3/4 full. This was in November. Then about 5 times after that. I will be on the last mark before empty and not only does it go from 80-70 miles to e to complete 0 miles, but my gauge goes from that mark to pass the e. I was driving my vehicle and it went from that same mark ( the mark right before the e) and just ran out of gas. I have took it to the shop twice and that can't find a code. They said if it happens again then bring it back in. But the inconvenience I have to wait until I have time. It happened today Feb 10 2014 and I raced to a gas station. I don't want it to happen and I'm driving in traffic and have an accident because my gas gauge is wrong and I stop in the middle of traffic. I don't want to get stranded somewhere either because I have a kid. I have seen same complaints about this vehicle. So I'm very concerned.
Engine stumbled and then lost power. It re-started but idled at 750rpm. Car would not accelerate. Placing the car into neutral and depressing the accelerator did not increase the engine speed. This persisted about 3-4 minutes. Afterwards, the engine speed responded to the accelerator, and when placed in gear, accelerated normally. This has happened three times in the past year.
Check engine light went on and when diagnosed it was one of the oxygen sensors. It had to be replaced in order for the rest of the safeties to operate properly. It was a defective part that cost over $400 to replace. Warranty was declined, however, the design life of the part must be in excess of 150000 miles. If this part were failing all the time, there would be a recall. My defective part was not replaced by Ford as it should have been. There are no moving parts, it should not wear out.