Results 1 to 10 of 10

Thread: Knock Sensor Install

  1. #1
    Fuel Injected!
    Join Date
    Mar 2013
    Location
    Federal Way, WA
    Age
    62
    Posts
    99

    Knock Sensor Install

    I am getting stuff together to retrofit a TBI onto an '83 V8. I had to drain the coolant the other day so took that opportunity to try to install a knock sensor. The right hand plug is behind the starter with no room for the sensor so I went to the left side. Using an impact wrench turned down low I was able to remove some of the plug. It sheared about 3/8" up. Rather than take any further risks I added thread sealant (was weepeing coolant) and put the plug back in.

    So what options do I have for installing the knock sensor? I have heard of some people using a fuel pump block off plate as an install point. Since this is in a dedicated wheeler I plan to keep the mechanical pump as a lift pump feeding a surge tank so that's out. Any other ideas?


    Thanks.

  2. #2
    Super Moderator dave w's Avatar
    Join Date
    Feb 2011
    Posts
    6,268
    I'm thinking for the knock sensor to correctly work, it has to come in contact with the coolant. I don't know if its a good idea or not, but what about using one of the pipe threaded holes in the head? Might not be a good idea, because of the rocker arm noise?


    dave w

  3. #3
    RIP EagleMark's Avatar
    Join Date
    Feb 2011
    Location
    North Idaho
    Age
    63
    Posts
    10,477
    They are supposed to be in coolant but I've seen then screwed in a bolt welded to block and work... who knows how accurate? All that said if it's a rock crawler you'll need to turn it off when hitting rocks or loose spark and idle and control and ... well all it takes is a hit on frame and you get retard.

    1990 Chevy Suburban 5.7L Auto ECM 1227747 $42!
    1998 Chevy Silverado 5.7L Vortec 0411 Swap to RoadRunner!
    -= =-

  4. #4
    Super Moderator
    Join Date
    Mar 2011
    Location
    Camden, MI
    Age
    35
    Posts
    3,026
    no 60V6 has a knock sensor in contact with coolant, so there is at least one example of GM not doing that.
    1995 Chevrolet Monte Carlo LS 3100 + 4T60E


  5. #5
    Fuel Injected!
    Join Date
    May 2011
    Location
    Pocono's PA.
    Age
    50
    Posts
    370
    I have made my own adapters to go from 3/8-16 standard bolt thread (male) on one end to the knock sensors 1/4" NPT (female) on the other , have a few in use right now .

    FWIW, all Gen VI (and some Gen V) BBC engined have the knock sensor hole blind tapped , so it does not see coolant .

    TOM
    1994 3500 Dually , 502 (509) , 264HR , Edelbrock MPFI , PFI '7427
    1992 S-10 434 SBC/Tremec - '7427
    1986 Monte Carlo SS
    1984 S-10 , SAS, 496/700R4/205 , D44/14BFF -'7427
    1980 Z-28 496/700R4
    1979 Corvette 496/700R4
    1977 Olds 98 Regency 403/700R4

  6. #6
    Fuel Injected!
    Join Date
    Sep 2012
    Location
    washington indiana
    Age
    69
    Posts
    884
    I have a 1993-95 4.3 it has one on the drivers side head that goes into the coolent chamber, it has one on the passenger side head that screws into the back of the head it dosnt contact any coolent it is the one I use 4k the left side I think was 8k.

  7. #7
    Super Moderator
    Join Date
    Mar 2011
    Location
    Camden, MI
    Age
    35
    Posts
    3,026
    odd that impedance would be different... looking at the diagrams, both the PCM and VCM equipped models have them wired in parallel. combined, they would represent a 2667 ohm load.... kind of odd.

    alldata is saying both are 8200 ohm units... that would make a 4100 ohm load, which is what i would expect to see.
    1995 Chevrolet Monte Carlo LS 3100 + 4T60E


  8. #8
    Fuel Injected!
    Join Date
    Sep 2012
    Location
    washington indiana
    Age
    69
    Posts
    884
    some one put this engine in the truck before I got it, the original engine only had one sensor. the sensor I took out was the same as the left side if I remember right.my wiring horness only has one knock sensor conector on it. that may be why I cant run 195 thermostat with out a bunch of knocks?

  9. #9
    Fuel Injected!
    Join Date
    Mar 2013
    Location
    Federal Way, WA
    Age
    62
    Posts
    99
    I did a bunch of reading and am beginning to wonder. I'm wondering if what I thought was a sheared off plug might have been scale and crud and the end of the plug might have just been corroded into an uneven surface. When I have a chance I am going to pull the plug again and try tapping the plug/crud with a punch and see if it falls out. If not, I'll see if there is enought thread to install the sensor there anyway. It might not be as sensitive as if it were immersed in coolant, but better than nothing.

  10. #10
    Fuel Injected!
    Join Date
    Sep 2012
    Location
    washington indiana
    Age
    69
    Posts
    884
    that is proble crud you see, if you take that plug back out flush the block good with water the 1,3,5,7 side is good about collecting crud in the rear side of the coolent passage.

Similar Threads

  1. Knock Sensor, Knock Filter, ESC and swaps!
    By JeepsAndGuns in forum GM EFI Systems
    Replies: 43
    Last Post: 12-23-2023, 03:17 AM
  2. Which 7427 knock sensor?
    By CDeeZ in forum GM EFI Systems
    Replies: 7
    Last Post: 07-06-2012, 03:39 AM
  3. knock sensor not detecting knock
    By PJG1173 in forum GM EFI Systems
    Replies: 6
    Last Post: 03-11-2012, 07:40 AM
  4. Adjustable Knock sensor
    By EagleMark in forum GM EFI Systems
    Replies: 1
    Last Post: 07-31-2011, 03:36 PM
  5. Placement of knock sensor
    By rsgt in forum GM EFI Systems
    Replies: 3
    Last Post: 05-29-2011, 05:45 AM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •