I am hoping to get some ideas from everyone as to what this might be. The scenario is this;

• 2007 fx4 scab
• Newly installed edge programmer
• Truck running smoothly (pre-trip)

I volunteered to help my bro move from Edm to Vancouver Island. I pulled a 12 ft u-haul trailer packed to the hilt! The drive is a bit of a challenge with the mountain passes, I really tried to take it easy with some of those pulls up the hill.

After I dumped my bro and his junk for a turn n burn I noticed that my truck now makes a clunk (sounds like right under my feet) everytime I start it up. Everything seems to running fine, no codes no engine lights, just this dam clunk when I turn the key to start the truck???

Thoughts...
Leon

 

Does it do it when you crank the engine up or just when you turn the battery on?

 

It does it when I crank the engine...

 

but it does not do it everytime..?? Seems not to have any pattern as to when it happens, sometimes yes and sometimes no??

 

Mount/s, (motor or tranny)?

Maybe have someone look under there while you crank it and see if they can see/hear and pinpoint the problem.

 

I forgot to mention, there are tons of threads about "driveline" clunks, but yours sounds like a different issue. Most of the others are when they start rolling (slip yoke) or turning (differential).

Just food for thought.

 

X2 on the mounts

 

Good suggestions, I will give them a try after work. To add to the description;

The sound happens when I first start the truck after it has been sitting for awhile. I will start the truck and hear the clunk while I am cranking, however if I stop the struck and start the truck right away there is no sound?