Thuds after shutdown

Anyone ever sat in their truck for a few minutes after you turn it off? I hear the usual relay and solenoid noises clicking, but there are also two distinct "knocking" sounds from the engine bay...sounds like somebody knocking the firewall twice with a broom handle...it's not a metallic sound....more of a dull thud...wonder what it is?

 

I hear something as well. Just one "clunk" after it shuts off. Its tough to tell where it is coming from. I am now thinking it may be a noise from below my seat as it goes all the way back upon exit.

 

Could it be your radiator shutters?

 

When I brought mine in for the TSB to fix the throttle hesitation, my dealer told me they fixed the transmission "thunk" as well. The throttle hesitation came back but the thunk did not.

 

What month was your truck built?

 

It’s probably brake system actuators.

 

On the 2nd gens, there is a thump from the HVAC system 30 seconds or a minute after turning the key off. It's one of the blend or vent doors opening or closing. Whatever it does, it keeps the inside of the truck from fogging or icing up in the winter. The windshield still ices up on the outside, but the inside doesn't like all of my past vehicles did. It can sound like it's coming from the engine bay but is in the dash near the firewall.

Perhaps the 3rd gen does it, too.

 

Is this a Hybrid?

 

Yes

 

I'll bet theres a lot of stuff shutting down on a Hybrid. A/C compressor, brake booster pump, trans booster pump, coolant pumps and a host of others. In my non hybrid there are emissions equip that click for awhile after a run. Some like 30 mins to an hour later.

 

When I am setting still for a while and the system decides to shut down the gas motor I almost think someone has hit me in the back. The thud shakes the whole truck. Every time it does this I think about what this means long term. I don't think this can be good.
Sometimes I feel some of this thud when I am shutting down the truck.
PT in Tennessee

 

It was built Sep 2022.

 

That happened every time in my hybrid also, seemed consistent during my ownership and I wasn't concerned about it

 

Probably the ac comp. My truck thuds on startup if I left the ac on.

 

Why?