Found a random mystery bolt in the engine compartment

See the little flange around the head You see those in various places on the car like in the timing cover and things like that found it on what side of the car?

 

I have never seen a 13mm hex on a Toyota. The 8.8 on the head indicates the "hardness" of the bolt.

Likely someone just was looking to replace some missing fastener and dropped it while underhood. Gravity never misses a chance to make you grumble and curse.

Posted via the PriusChat mobile app.

 

Did you determine it was 13 mm (socket size) by testing with a 13 mm socket. Maybe not even metric, a 1/2” (socket size)? If you’ve got a caliper or micrometer check diameter at the threads.

Just a guess: it’s not from you car, just kicked up from the road while driving.

 

I think that's the length maybe about a half inch hell I don't know I don't have the copy of the picture against the Swanson scale but that is a Toyota bolt I've got a bunch of them over here in the thing and I may even have a match for it but I'm not sure where it goes usually with the extra little lip around the head of the bolt you know so it can't bury itself on a socket all the way up to the threads is usually clamping something with the gasket or FIPG like the timing cover not that this is where that came from generally speaking one would hope. And then I have a bunch of these on my Italian motorcycle exactly like this with the same dimple in the head and everything but not the point at the end of the threaded shaft which indicates to me that might penetrate and go into an open hole not flat like a blind hole thread

 

Again, 8.8 on the bolt head is a "metric only" hardness rating. You will not see that on imperial bolts. Given a 13mm hex, it looks like a 8mm x 1.25 pitch, about 40mm long.

Posted via the PriusChat mobile app.

 

This is not a Toyota OEM bolt.

All Toyota bolts use the Japan Industrial Standard (J.I.S.).

All M8 J.I.S. standard bolts use a 12mm hex head.

Toyota bolts are never marked 8.8. They are marked with a "9."

 

Prius doesn't use that bolt anywhere

 

Did you park (too close) next to a Gen 2 Range Rover? Stuff fell off mine all the time....