Strange Thud

[Got Diesel]

I know that this is a funny title, but that is exactly what it is. About 10 or 15 seconds after I start my truck every time I start it, there is a strange thud. It sounds like it is coming off of the back of the engine, or around the transmission. I know that this is kinda out of left field, and open to discussion but any ideas of what it is. If there is more info needed I will be happy to give all that I can. Thanks

 

[whatabudro]

That would be Fords lovely vacuum operated air conditioning/heating system. When I first got my truck, I thought I was running over poodles. Nope, just some dampener slamming shut. I think there is a recall for it if bothers you a lot. Bryan

 

[Got Diesel]

Thanks. It doesn't bother me at all. Bothers the girlfriend when we come out of the movies and are sitting there, kinda scares the crap out of her. I was just wanting to make sure that this wasn't anything to do with the drivetrain. Thanks.

 

[CHPMustang]

I know that this is a funny title, but that is exactly what it is. About 10 or 15 seconds after I start my truck every time I start it, there is a strange thud. It sounds like it is coming off of the back of the engine, or around the transmission. I know that this is kinda out of left field, and open to discussion but any ideas of what it is. If there is more info needed I will be happy to give all that I can. Thanks

Oh that be the "blend door" closing/opening depending on your vent preference

Gets to be annoying after awhile but have to live with it

 

[HTRDDSL]

I just joined this site and you guys have already solved a mystery with my truck. I have a buddy with the same thing also . Now I can pass that info on. Thanks.

 

[NVCowboy]

Thank goodness that is cleared up. At least its not Poodles. Everytime I hear the damn noise, I am gonna think of that comment. That noise really was a mystery to me for as long as I have owned the truck though.