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Where is the oil pressure sensor?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by txbartman, Jan 21, 2002.

  1. txbartman

    txbartman 1/2 ton status

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    Okay, this is another crate install issue we ran into this weekend. We pulled two sensors off the 85 305 block. One was in the head between the front two plugs a little above there centerline, closer to teh centerline of the headers. I believe it was in the driver's side head. The second sensor was down low in the block, just above the oil pan on the opposite side of the engine. I am assuming one of these is the oil pressure sensor and the other is the temp sensor.

    The one down low on the block cracked when we pulled it. The guy at NAPA said it was a engine knock sensor? My truck had ESC originally, but is this true? He said if I wasn't going back with ESC that I didn't need it.

    Where is the temp sensor and the oil pressure sensor? I would hate to blow this sensor off and not have my guages.

    Brian
    Check out <a target="_blank" href=http://tx85gmcguy.alloffroad.com>My Jimmy</a> with all her projects!
     
  2. chevyracing

    chevyracing 1/2 ton status

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    The one on the left head is the water temp sensor, the oil pressure sensor is on top behind the manifold by the distributor hole.
    John

    Like to go sloppin' 'round in da mud in a rapid fashion....=)

    <a target="_blank" href=http://coloradok5.com/gallery/albun31?&page=1>BLAZER PICS</a>
     
  3. chevyracing

    chevyracing 1/2 ton status

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    Very rarely the oil pressure sensor is on the front of the engine just above the timing cover. The one in the back is a very small, about a 1/4 inch fine thread hole. (so is the one in the front). The hole in the back is used most commonly because it is out of the way. The only time I have ever seen the one oin the front used is when you want to run two gauge, for instance one electric, and one mechanical to cross check each other and to check for oil pressure blockages through the block.

    John

    Like to go sloppin' 'round in da mud in a rapid fashion....=)

    <a target="_blank" href=http://coloradok5.com/gallery/albun31?&page=1>BLAZER PICS</a>
     
  4. txbartman

    txbartman 1/2 ton status

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    Okay. On the back there was a hole in the block (on top) exposed even after the manifold was installed. It has a brass fitting screwed into it with two sensors hanging off of it. I forgot about those. So one of thos is the oil pressure sensor. What is the other one?

    Does anyone know what that sensor is that is located down low on the side of the block? Was the NAPA guy right? Is it a knock sensor?

    Brian
    Check out <a target="_blank" href=http://tx85gmcguy.alloffroad.com>My Jimmy</a> with all her projects!
     
  5. chevyracing

    chevyracing 1/2 ton status

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    I believe it is a knock sensor. It tells the computer to richen or lean the mixture as needed.

    At the very back of the block on the top is the small hole I assume you are speaking of. There shoul only be one sensor there that I know of unless one is for oil pressure and the other is for oil temp. The ooil pressure sensor generally is a cylinder that is about 1.5 inches across with a metal tap on top for a wire to hook to. It is usually about 2 inches tall or less. The oil temp sensors have a copper probe that stick out of them into the oil stream usually.

    John

    John

    Like to go sloppin' 'round in da mud in a rapid fashion....=)

    <a target="_blank" href=http://coloradok5.com/gallery/albun31?&page=1>BLAZER PICS</a>
     
  6. chevyracing

    chevyracing 1/2 ton status

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    I am going to send you a PM with my phone number. Give me a call.

    John

    Like to go sloppin' 'round in da mud in a rapid fashion....=)

    <a target="_blank" href=http://coloradok5.com/gallery/albun31?&page=1>BLAZER PICS</a>
     
  7. RaisedK5

    RaisedK5 1/2 ton status

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    Actually the knock sensor controls the advance on the distributor, which is funny because they say the factory approved method of testing that sensor is to hold a timing light on the marks and tapthe exhaust manifold with a hammer to see if the esc will retard the timing. kinda of funny, but ya on the pass side right above the oilpan rail is the knock sensor, the oil pressure sensor should be at the back of the manifold, and you possibly have a sensor right above the filter, which may or may not control the electric choke, i have one on my 80 camaro.

    Leland aka RaisedK5

    "The Voices told me to do it!"
    <a target="_blank" href=http://www.coloradok5.com/gallery/albun91>This is what they told me to do</a>
     
  8. bigmack

    bigmack 1/2 ton status

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    The two sensors on the back that you seen by the distributor are both for the oil pressure, from the factory some vehicles had a mechanical guage and a warning light, that is why there are two of them.
     

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