My parents have a 2007 Mercury Mountaineer, 100,845 miles. They change oil like a religion. It has under the hood ticking that increases and decreases with RPM. The ticking (tickity-tickity) sounds like when there is low oil. People have said,"You better put oil in there…"The oil is full. I can’t tell if the sound is coming from inside the engine, or if something on the engine might be loose that is causing the ticking as the engine RPM changes. From what I can remember from auto shop in the 80’s…it kind of sounds like valves/lifters.
Also, it has a strange road noise that I think is coming from the tires. It sounds and sort of feels like riding on knobby off road tires. I can put it in neutral and turn off the engine, and the noise remains and decreases as the speed does, so it is not from the engine.
Anyone have any ideas? Thanks in advance.