Anyone know what this spring is for?

[Jlohknox]

Dropped a few plastic clips in engine bay while replacing bad Horn. Fished a few out of bottom skid plate and found this spring in the back. Had the truck in recently to replace a bad water pump/thermostat.

 

[Nex]

Looks like it could be a t-stat spring.

 

[Bozz]

Great Scott! DO NOT DRIVE without that spring!!! That is the flux-capacitor stabilizer spring. Terrible things could happen if you drive without it and get anywhere close to 88mph!

 

[Jlohknox]

Looks like it could be a t-stat spring.

Usually those don’t come out of the thermostat do they?

 

[GCATX]

I wouldn't worry about it. My neighbor came by the other day. His new F150 had a crumpled beer can that bounced up into the hole next to front license plate. He's old and never saw it.

 

[thatJeepguy]

Mattress?

 

[Nex]

Usually those don’t come out of the thermostat do they?

They do if the thermostat brakes. Could be what caused your failure and needing replacement.

 

[Jlohknox]

For comparison spring compared to Thermostat. Not sure I trust the dealer because I checked the coolant reservoir before I left and it wasn’t filled up correctly and now I find this random spring.

 

[CleverGirl_]

looks like a wastegate spring but that doesnt seem right considering what they touched