Random bolt left over during reasembly. I think its going to be something related to the shortblock. Could be the heads but I doubt it. For the life of me i cant figure out what its for. Winner gets a pat on the back. Thanks.

 

Could be the ground bolt on back of driver side head

 

oil pan plug?

 

Its not the oil pan plug and is smaller than the ground bolts.

 

Isnt there a ground on the side of the block?

 

Looks like one of the four cam plate bolts

 

How about on the passenger head, in the spot where the temp sensor is on the driver side?

 

No. There is a black hex plug in that one.

It fits the ground on the side of the block. Only problem is that I can see shiny metal as if the bolt head is a little too small.

 

Darn. Good luck haha.

 

Looks like it could be the bolt for the transmission or oil dipstick tube.

 

Too small. Oh well. Atleast there was only ine left over lol. Im sure ill figure it out.

 

That bolt holds the crank sensor to the block. I just twisted one in this past weekend.

It's the same as the cam sensor uses, 8mm x 1.25 x 20mm long.

 

The back of the head grounds use a full size head bolt, not a smaller hex flange head bolt.

 

Double checked cam and crank sensor bolts and they are both the same. Slightly longer than the one pictured above. This bolt is yellow/bronze on the threads/inside head of the bolt. The head is dirty, not oily. So likely from outside of the block. Ill figure it out.

 

I'm sure a longer bolt will fit these sensor locations.

 

That looks like the bolt on my LQ4 that held the strap for the oil cooler lines and threaded into the side rail of the oil pan.

 

I'd be more worried about the loose nut behind the wheel.

 

maybe one of the front or rear main seal plate bolts?

 

No, they're longer.

These short bolts are used to hold thin things to the block. The crank & cam sensors have a thin sheet metal tab the bolt goes through.

I think the oil pump tube to oil pump also uses this short bolt.

 

This was for a truck motor, but it may help.