I just purchased a 2002 F150 XL with the V-6 engine and 2WD. When I turn my key to accesories (the point right before I start the engine) I hear the fuel pump turn on and the gauges function up. Well shortly after this about 3-4 seconds, I hear a clunk sound. It doesn't necesarily sound bad but I just want to make sure it's normal. It sounds like maybe an emission thing or something. Anyone else have this?? Any insight into this noise would be great. Thanks!!b

 

I've never noticed a clunk before I start my v6. Except for hearing the fuel pump kick in. And it's a 2001.

 

nebakanezer, I too hear that noise you are talking about. To me it sounds like a relay of some sort. When you first turn the key you hear the fuel pump then the clunk and the fuel pump stops. I have the 4.6 L though.

 

I think you guys are hearing the ABS self-test cycling.

 

yeah I think that clunk sound and the ABS light flash / occur at the same time? I dont remember now but I think it's normal and part of the abs system.

 

Should have mentioned about what I did with my '99 when the question of this "thunk" came up.

I opened the hood and lowered the driver's window. Then while standing outside the truck, turned the key on and put my finger on the ABS box. It thunked.

My '01 has a different ABS box, so not sure if it still does it.

It's one of those things that I never really notice until somebody mentions it here. It's like the clicking of the exhaust system when you shut down the engine. I never notice it until I read about it here, then it takes me a week or two before I start to ignore it again.

 

I guess you guys are right about the ABS thing cycling. That makes more sense

 

My truck has made the same noise since day one .