Author Topic: Oil pressure sending unit location  (Read 43109 times)

Offline Skunksmash

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Oil pressure sending unit location
« on: January 27, 2012, 05:39:27 PM »
I've been grubbing around under the hood looking for my oil pressure sending unit on my 87 5.7L. Only thing is it looks like somehow there are two of them? How to tell which one is which? Where is it supposed to be located?

Online bd

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Re: Oil pressure sending unit location
« Reply #1 on: January 27, 2012, 05:45:36 PM »
If it's TBI, the 2-wire switch at the back of the intake next to the distributor is for your fuel pump.  See subsequent post below.
« Last Edit: January 27, 2012, 09:15:31 PM by bd »
Rich
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In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Lt.Del

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Re: Oil pressure sending unit location
« Reply #2 on: January 27, 2012, 06:18:22 PM »
it could be on an extension, looking down at your distributor, it will be just to the right.  It looks like a 2 or 3" bulb.
with my distributor out.....

« Last Edit: January 27, 2012, 06:50:52 PM by SgtDel »

Offline Red 83

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Re: Oil pressure sending unit location
« Reply #3 on: January 27, 2012, 06:39:39 PM »
If it's carb'd, the one at the back of the intake next to the distributor is the oil pressure sensor. At least that's the way it is on my '84 305.
1983 C10 Scottsdale - 305, TH350  Ol' Red

Offline 1980c10

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Re: Oil pressure sending unit location
« Reply #4 on: January 27, 2012, 06:50:05 PM »
It is the one by the dist. w/ one wire. The other is an oil pressure switch for your choke.

Online bd

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Re: Oil pressure sending unit location
« Reply #5 on: January 27, 2012, 09:14:19 PM »
This image of the 'fuel pump oil pressure switch' on an '87 5.7K TBI engine shows the switch at the back of the intake.  See SgtDel's image for best picture of location.  It has one orange and one tan/white stripe wires connected to it. 
The sender for the 'oil pressure gauge' may share the same fitting, but has only one tan wire attached.  An alternate location for the 'oil gauge sender' is down by the oil filter.  I hope one of us answered your question.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Skunksmash

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Re: Oil pressure sending unit location
« Reply #6 on: January 28, 2012, 05:22:56 PM »
Yes the one tan wire will help me locate the proper one. Apparently they just look the same. My truck isn't carb'd though.

Offline Irish_Alley

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Re: Oil pressure sending unit location
« Reply #7 on: January 31, 2012, 11:02:05 AM »
what do you mean theres two of them?
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Offline Captkaos

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Re: Oil pressure sending unit location
« Reply #8 on: January 31, 2012, 04:46:53 PM »
Yes there are 2 oil sensors on the 87's.  The one by the filter feeds the gauge (typical of the normal non TBI) the one at the back of the intake goes to the ECM.

Offline Irish_Alley

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Re: Oil pressure sending unit location
« Reply #9 on: January 31, 2012, 08:45:48 PM »
knew of both locations. just wasnt sure if he knew that there's a difference in the gauge one and light one, so it could be one of the three
If you canít tell yourself the truth, who can you tell it to?~Irish_Alley

When you have eliminated the impossible, whatever remains, however improbable, must be the truth ~Sherlock Holmes

Offline Skunksmash

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Re: Oil pressure sending unit location
« Reply #10 on: February 23, 2012, 04:57:57 AM »
Do yall think a bad oil pressure sending unit could be responsible for the battery running down? Since its EFI, I think the computer may just sit there and run the fuel pump until the battery runs down if the oil pressure sending unit is dead.

Offline Captkaos

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Re: Oil pressure sending unit location
« Reply #11 on: February 23, 2012, 11:03:37 AM »
With no power to the system there is nothing to close the oil pressure switch to power the pump, this is just a backup for the fuel pump relay.  It will keep the truck running with key on if the relay goes bad.

Offline Skunksmash

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Re: Oil pressure sending unit location
« Reply #12 on: February 24, 2012, 03:44:32 AM »

Offline Skunksmash

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Re: Oil pressure sending unit location
« Reply #13 on: February 29, 2012, 07:22:49 PM »
Yes there are 2 oil sensors on the 87's.  The one by the filter feeds the gauge (typical of the normal non TBI) the one at the back of the intake goes to the ECM.

Wait there is another fuel filter? I only replaced the one that is at the back of the truck. I think it was on the frame rail, can't remember. There are two of them fuel filters?

I have the oil pressure sending unit that looks like the one in the pics, but I'm having trouble locating it. Probly need to look in the daytime lol. It seems to be buried under there, under all that mess of plugwires and stuff. I might have to pull the coil so that I can get at it easier.

Offline Lt.Del

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Re: Oil pressure sending unit location
« Reply #14 on: February 29, 2012, 09:32:41 PM »
oil filter