I have a 2007 with the 5.4 flexfuel engine. It is only 2wd but also has the factory towing package on it. I have only owned it for about 1.5yrs and it has 98k miles on it. In the last 6 months I have been hearing a ticking sound at low rpm coming mostly from the passenger side. I have been trying to listen and pinpoint it along with reading a lot on the forums here. There seems to be some mixed opinions and not truly the same sound from what I can find. It does not matter the speed of the vehicle. Whether moving or from a stop, if the rpm's are below 1k and I lightly press the gas I get a ticking sound. Here in the last 2 months I have noticed a significant drop in fuel mileage. I have tried running some Berryman's in the gas and other types of fuel injector cleaners with no success other than gaining a bit of fuel economy with the Berryman's. I did have a shop run only 5 quarts of oil in it and I had to top it off (when I noticed it 1 week later) but that was months ago and ticking didn't start until approx 3k later. Wonder if anyone else has experienced this? Have looked for an exhaust leak and can't find any. Gonna check the manifold to see if it is loose this weekend. I have service records showing the plugs replaced around 60k, but am wondering if they or the injectors could be causing the problem.
Thanks. Will check it out. I have read about some of the spark plugs cracking and causing similar issues. Will be doing that this weekend.