Mystery threaded hole Explorer

[74lumenaire]

What is the threaded hole in the back of the engine of a 1997 5.0l explorer? It’s on the passenger side of the engine in the very back. It is very close to the bell housing were the 4r70w bolts up on the flat. I don’t know if it’s a oil passage that needs plugged or what! It’s been awhile since Instripped the engine down!
Pics if you have them

 

[74lumenaire]

Only a few inches from the pcv valve! Pointing up!

 

[904Bronco]

This one? The threaded hole...

Never seen anything mounted to this hole...

 

[fishinman78]

I think it's the knock sensor which the explorer doesn't use.

 

[PaveBronco]

Good excuse to put a grounding strap to the firewall there. Can never have enough it seems.

 

[74lumenaire]

That’s the hole I was talking about! Don’t remember having anything screwed in there!! I’m just gonna plug it and see what happens!

 

[B RON CO]

Hi, my guess is if the head was installed on the left side there would be an accessory or bracket for that bolt hole. Good luck

 

[Viperwolf1]

That’s the hole I was talking about! Don’t remember having anything screwed in there!! I’m just gonna plug it and see what happens!

You mean the hole that has a bolt in it in the picture above? It's going into the back of the head. That was used for the explorer trans dipstick tube.

Never mind. I see you have it figured out and tapatalk won't let me delete.

 

[DEEPWOODS]

Transmission dipstick tube was fastened there

 

[Crush]

heads are also switchable from left to right so the holes in the front of the head for your accessories will also be in the back of the head. BUT, i believe he was talking about the hole in the top of the block that is circled in red

 

[jagbucket]

i think fishinman has the right answer . i have the same block and there is a soft plug in it so not used, although not sure if its a knock sensor, but you only need to plug it