Hi guys,
I have a 2008 Sport 4.0L V6, SOHC. 230,000 KM on it.
Today I noticed a high pitched sound coming from under the hood. It seemed to disappear when I let off the gas. Didn't get louder or change pitch with gas, it just appeared and pretty much stayed constant. It is there at idle as well, so I was able to get a video when I got home.
I don't think it's a belt or pulley, but maybe I'm wrong. I tried giving the belt a squirt of WD to see if it changed, but nothing happened. Belt is tracking straight on all the pulleys so far as I can see. The sound seems to be coming from further back, almost like it's right on top of the engine.
I used a mechanics stethoscope but couldn't find anything that gave it away. I climbed right up on top and put my ears all over the engine bay, but it just seemed to be everywhere.
If I 'blip' the gas, it stopped and returns when the RPM returns to idle.
Any ideas or things to try to eliminate?
Have a listen, it's most clear around 10 seconds or so. Gotta have the volume up.