Oil pressure sensor 305 / 350

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newguy11

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1985 c10

I swapped my 305 for a new 350. And relocated the oil pressure sensor from behind the distributor to above the oil filter.

FYI to plug the oil suppy hole behind the distributor you will need a 1/8 NPT plug, they can be had at any hardware store for 5$ or so.

To mount the sender to the side of the block I used a 3” ext with 90 deg port from a TBI motor and a 1/4 male to 1/8 female adapter.

Hope this is of use to someone.
 

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rcotner

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Newguy11, looks like this is the exact setup on my 87 R10 Chevy 305 ci. Mine is currently leaking and looking to replace it. When I go to the parts store what exactly is the name of the part I need as I’ve heard it called sensor and/or switch? Thanks
 

newguy11

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Newguy11, looks like this is the exact setup on my 87 R10 Chevy 305 ci. Mine is currently leaking and looking to replace it. When I go to the parts store what exactly is the name of the part I need as I’ve heard it called sensor and/or switch? Thanks

Rcotner, you need the pressure sensor it looks like a bell of sorts. The sensors job is to send a signal to oil pressure gauge.

The oil pressure (switch) has a couple jobs which I can’t remember at the moment. It’s located behind the distributor near the firewall.

Hope this helped
 

Rudy Mienert

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newguy11, I'm just trying to fix the non working oil pressure gauge on my recently acquired 87 C3500 dually, 350 TBI. So you are saying there is a sensor, AND a sender unit??...
 

Camar068

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newguy11, I'm just trying to fix the non working oil pressure gauge on my recently acquired 87 C3500 dually, 350 TBI. So you are saying there is a sensor, AND a sender unit??...
sensor/sender....same thing.
 

Bextreme04

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newguy11, I'm just trying to fix the non working oil pressure gauge on my recently acquired 87 C3500 dually, 350 TBI. So you are saying there is a sensor, AND a sender unit??...
The TBI is different than what he has on his 85. You will need to look at what you have. If it is a single wire, it is the oil pressure sending unit. Two pins will be a pressure switch for the fuel pump. Three pins means it is a combined sender/switch. Generally the pressure sender is near the distributor and the switch is near the oil filter housing on a SBC.
 

mibars

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Is there a way to remove that 3 prong sensor of a 350 TBI without removing distributor?

EDIT: Just found out that dedicated sockets exist for these sensors, my sensor seems to measure about 30 mm, looks like possibly 1 3/16 in (that's about 29 mm), but my new sensor is smaller, measuring about 27 mm (I guess 1 1/16 in)... Let's hope that I can find deep enough metric sockets to deal with these sensors
 
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bucket

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Is there a way to remove that 3 prong sensor of a 350 TBI without removing distributor?

EDIT: Just found out that dedicated sockets exist for these sensors, my sensor seems to measure about 30 mm, looks like possibly 1 3/16 in (that's about 29 mm), but my new sensor is smaller, measuring about 27 mm (I guess 1 1/16 in)... Let's hope that I can find deep enough metric sockets to deal with these sensors

One of my deep sockets for oil senders is actually stepped inside, so it fits the two most common sizes. Look for one of those.
 

AuroraGirl

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Rcotner, you need the pressure sensor it looks like a bell of sorts. The sensors job is to send a signal to oil pressure gauge.

The oil pressure (switch) has a couple jobs which I can’t remember at the moment. It’s located behind the distributor near the firewall.

Hope this helped
the switch is for a dummy light or for electric choke functionality (The electric choke would be run through the one by the oil filter in order to not bleed the battery with key on engine off )

The the one behind the distributor is where the switch or sensor for your gauge normally would be. hes just opting to put his elsewhere which hopefully it lasts/stays good down there. nbot sure why it wouldnt but hoping the best
 

mibars

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One of my deep sockets for oil senders is actually stepped inside, so it fits the two most common sizes. Look for one of those.
I found online sockets that are stepped to both 1" and 1"1/16, but not to both 1"1/16 and 1"3/16. Anyway doesn't matter as I finally managed to get the old one loose with small vice grips under distributor.

Now my gauge shows zero at engine off and... 15 psi either long cranking or cold idle (!) Haven't driven it an inch so I'll not make any verdicts yet...
 

AuroraGirl

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I found online sockets that are stepped to both 1" and 1"1/16, but not to both 1"1/16 and 1"3/16. Anyway doesn't matter as I finally managed to get the old one loose with small vice grips under distributor.

Now my gauge shows zero at engine off and... 15 psi either long cranking or cold idle Haven't driven it an inch so I'll not make any verdicts yet...
15 psi exact? it may be a oil switch not a sensor if you are only getting a fixed value
 

mibars

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350 TBI

AuroraGirl

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mibars

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is your gauge working right, can you peg it and sink it to zero with unresisted powerr and a full ground
Yes, I checked gauges couple of months ago. With my old sensor irmt was at 30 psi all the time. Also with sensor unplugged or new one plugged but not grounded it pegged over 60
 

AuroraGirl

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Yes, I checked gauges couple of months ago. With my old sensor irmt was at 30 psi all the time. Also with sensor unplugged or new one plugged but not grounded it pegged over 60
interesting
 

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