• Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Engine Mystery threaded hole on block

  • Thread starter Thread starter stang80s
  • Start date Start date Mar 29, 2021
S

stang80s

New Member
May 14, 2015
2
0
1
Mar 29, 2021
#1
  • Mar 29, 2021
  • #1
Hey guys, I am in the middle of a intake manifold install on my 84 gt vert with a 90+ engine installed. On the back of the block near the firewall I see this threaded hole and nothing was connected to it. Does anyone know what it is for ? Picture attached. Thanks
 
M

mostsmooth

Active Member
Nov 12, 2002
270
26
29
Mar 30, 2021
#2
  • Mar 30, 2021
  • #2

What Is This Hole On The Top Rear Of The Block?

What hole is the one that is circled red? I believe the blue circle is an oil galley plug, but I do not know what the other hole is. It is threaded. (This is not my actual picture, so mine is not filled with orange RTV.) I was replacing the lower manifold gasket and noticed this hole filled with...
www.stangnet.com
 

Boostedpimp

20+ Year Stangneter
May 8, 2003
1,451
493
154
NJ
Mar 30, 2021
#3
  • Mar 30, 2021
  • #3
Do yourself a favor and clean out that pvc valve screen if there is one it looks a good bit full (larger whole next to the area where your arrow is pointing)
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,248
17,930
224
Massachusetts
Mar 30, 2021
#4
  • Mar 30, 2021
  • #4
For the knock sensor that came on the F1SE block used in 1991+ 302 engines that were in Mustangs and other fords with the 302. I believe only the F150 used the knock sensor.

Does confirm you do have a 91+ engine
 
Reactions: manicmechanic007

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
7,387
2,745
194
Kearney, NE
Mar 30, 2021
#5
  • Mar 30, 2021
  • #5
@a91what does a MS EFI have a use for an knock sensor?
 

a91what

SendMeUrDataLog
10 Year Member
Apr 6, 2011
10,739
6,720
214
Hillsborough county
Mar 30, 2021
#6
  • Mar 30, 2021
  • #6
Depends on the system. My MS3pro has a built in knock circuit, I just supply two GM style knock sensors threaded into the back of the head. It takes some setup but works well.

something to note is that a knock sensor can be blinded by excessive mechanical noise and thus rendered useless
 

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
7,387
2,745
194
Kearney, NE
Mar 30, 2021
#7
  • Mar 30, 2021
  • #7
a91what said:
Depends on the system. My MS3pro has a built in knock circuit, I just supply two GM style knock sensors threaded into the back of the head. It takes some setup but works well.

something to note is that a knock sensor can be blinded by excessive mechanical noise and thus rendered useless
Click to expand...
Do you have a GM sensor # small enough to use the 302’s accessory bolt holes, or do they use the thermactor plug holes?

Mechanical noise is a concern on my other, air cooled project where a knock sensor would be helpful with increased operating temps under load.
 

General karthief

wonder how much it would cost to ship you a pair
20+ Year Stangneter
Aug 25, 2016
27,902
10,555
203
polk county florida
Mar 30, 2021
#8
  • Mar 30, 2021
  • #8
a91what said:
something to note is that a knock sensor can be blinded by excessive mechanical noise and thus rendered useless
Click to expand...
Reminds me of an ex wife
 
Reactions: Wayne Waldrep, limp and 7991LXnSHO

7991LXnSHO

wanna catch the space herp
10 Year Member
Sep 1, 2010
7,387
2,745
194
Kearney, NE
Mar 30, 2021
#9
  • Mar 30, 2021
  • #9
Sorry to derail this more, but who was making excess mechanical noise, and who was rendered useless? I am sure there is a lesson for us here, but there is no need to answer if you are in witness protection.
General karthief said:
Reminds me of an ex wife
Click to expand...
 
Reactions: General karthief

limp

wrap a little cheese around it and its a done
5 Year Member
Oct 4, 2020
5,465
2,898
173
Florida
Apr 1, 2021
#10
  • Apr 1, 2021
  • #10
7991LXnSHO said:
Sorry to derail this more, but who was making excess mechanical noise, and who was rendered useless? I am sure there is a lesson for us here, but there is no need to answer if you are in witness protection.
Click to expand...
I wish I could help with an answer here but mine got rid of me 26 years ago so I can't remember.....
 
You must log in or register to reply here.

Similar threads

T
Fox Help Request: Clutch Cable Installation on T5 Swap — I Can’t Find the Mounting Hole
  • TDM389
  • Feb 19, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
1
Views
156
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Feb 19, 2026
nickyb
2
Running very very rich
  • 2esoteric
  • Oct 31, 2025
  • Fox 5.0 Mustang Tech
Replies
4
Views
334
Fox 5.0 Mustang Tech Oct 31, 2025
Noobz347
Mustang II 4 cyl gear hunting and possibly messed up vacuum system
  • oesterreicher
  • May 31, 2026
  • 1974 - 1978 Mustang II Talk & Tech
Replies
11
Views
266
1974 - 1978 Mustang II Talk & Tech Jun 14, 2026
manicmechanic007
S
Fox '87 GT can't get to stay running
  • spilly
  • Mar 29, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • 2
Replies
27
Views
763
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Jun 20, 2026
spilly
S
Vacuum line question?
  • Mustang Momma
  • Feb 10, 2026
  • 1996 - 2004 SN95 Mustang -General/Talk-
Replies
1
Views
161
1996 - 2004 SN95 Mustang -General/Talk- Mar 3, 2026
Noobz347
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?