How many of you have a clunk or thump sound shortly after you start your truck. Feels like someone is knocking on the floor of my truck.........


Matt

 

I have experienced the same noise. I dont know what it is but it does seem like someone is knocking on the floorboard. Any ideas on the situation would be greatly appreciated.

Thanks

 

Yeah, I get that almost everytime I start my truck. It only happens right away, and then never again until you stop and start the truck again.

 

I haven't noticed this happening in my truck, but I'll definately listen for it now.

 

it could be that the midget inside of your truck gets new hope that he might get out of his cage everytime you start your truck. his hopes are dashed when he knocks himself unconscious banging his head on your floorboard. c'mon, have a heart, let the little guy out...

 

I have not heard this noise on mine that I know of. I'll pay attention over the course of the next few days to check if I do hear it.

 

No noises here...

 

The only noise I've noticed is the headlight relay in the dash if I have the automatic lights on.

 

I have had three 150s (98, 01, and now 04) all three have had this nosie, I think it is the air box opening or closing the outside air or when the air deflector is moving inside the air box. I have only noticed the nosie when the AC is on when I start the truck.

 

I have the 'thunk' too...appears to come from the passenger side just aft of the right front wheel. It doesn't occur EVERY time, but when it does it is just a single 'thunk' as I move forward from a rolling backout of my driveway in neutral.

 

I have the same thump within 3-4 seconds after starting the truck when it has sat overnight. Almost like someone hits the frame under the passenger seat with a rubber mallet.

 

i have the same thing. not every time but soon after i start the engine. i thought it was just me.

 

I park very close to the garage cabinets, when I back out the thunk makes me think I hit them, my heart skips a beat every time, you'd think I'd be used to it by now.

 

I have the auto climate control on mine, and it does the same thing especially noticable when in the Auto mode. It's the air diverter for the A/C system. Turn off the A/C before you start the truck.
Scott

 

Could it be the damper for the air conditioning closing or opening. I have noticed a similar sound when I switch on the auto temp.