I own a 2002 XL 2wd with a 4.2 and an auto trans. When I drive at speeds between 40 and 55 I hear a rattle coming from under the hood. When I hit the gas hard it goes away, and when I let off the gas it goes away. It almost sounds like pinging but it dosen't do this under load. I dont think it is an exhaust leak but I dont know for sure. I have looked under the truck and found no loose exhaust, or any sign of leakage. I have also tried to get it to make the noise when it is sitting in neutral but it wont. It only does this when I am moving. Has anyone else experienced this? Any input would be greatly appreciated.

Jersey Jeff

 

hey,

i know this is overly simple and may sound stupid, but sometimes these things get you. Is there something hittin the fan blades? Maybe there's a piece of plastic or something next to the fan that gets blown in at a certain speed.

 

thanks for giving me some ideas!

you know, I never thought of that! thanks for the idea, I am going to check it out in the morning.

jersey jeff

 

sup man i got a 2002 f150 4.2v6 xlt. i clocked mine on the rpm meter. mine happens when it hits 1 to one 1.2 rpm's. when it idle nothing happens and when i go over 1 to 1.2 rpm's it goes away. now when i drive it at 1-1.2 rpm's it there. thats around your 30 mph scale also. i took it to the ford and they found rocks in the converter shield. check your converter shield man. could be the problem. and take it to the ford service place or a guy who knows how to fix things. laterz

 

Hey JJ, did you get it fixed? I think my 4.2 has the same condition, it makes a light pinging at steady-state throttle at cruising rpm.
On mine I am sure it is simply pinging, as it disappeared when I tried some premium. I think in my case I may have an intake leak which is not helping the problem, hopefully you do not either.

 

Did anyone ever figure this out? The original post is EXACTLY what my 4.2 is doing. This is the only noise my truck makes and I have to drown it out with the stereo......