Bad and high oil pressure gauge/sensor/sender???

[Tomas Urrabazo]

Does anyone know what is going on with my oil pressure sensor? It is constantly bouncing and pegs all the way out making a clicking sound. My AC compressor may have something to do with this because it is cycling every couple seconds and when it cycles that’s when the gauge fills up??? I’m not sure. When i turn the AC compressor completely off, the gauge stops bouncing at idle, but when i press the gas it peg out at 60+ pounds.

Here is a video of the gauge from inside

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Here is a video of my AC compressor cycling.

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Thank you guys for your help i think it may be the oil pressure sensor or sender.

 

[PWC Repair]

Clean and retighten the grounds on the engine.

 

[Tomas Urrabazo]

Clean and retighten the grounds on the engine.

The ground straps? I think there’s 2 ground straps, one behind the motor and one by the ac condenser. Are there any others i should take a look at and clean up? Thanks

 

[Schurkey]

what is going on with my oil pressure sensor? It is constantly bouncing and pegs all the way out making a clicking sound. My AC compressor may have something to do with this because it is cycling every couple seconds and when it cycles that’s when the gauge fills up??? I’m not sure. When i turn the AC compressor completely off, the gauge stops bouncing at idle, but when i press the gas it peg out at 60+ pounds.

Download the service manual set for your vehicle, check the wiring diagrams for commonalities between the oil pressure harness and the A/C harness.

I'm really surprised that you're having oil gauge issues as the compressor cycles. I wouldn't have expected that.

i think it may be the oil pressure sensor or sender.

The '88--'89 small-blocks use a really-crappy oil pressure sending unit. I don't know if the '90 engines use the same one. My truck is on #4; and that's only in the time I've owned it. It's a 1-wire unit mounted on an extension, just above the oil filter. I think newer trucks use a smaller 3-wire sending unit beside the distributor.
www.automotiveforums.com/vbulletin/showthread.php?t=1136624

Oil Pressure Sending Unit--TBI V-8 dash gauge - Automotive Forums .com Car Chat

Oil Pressure Sending Unit--TBI V-8 dash gauge C/K

www.automotiveforums.com

Another possibility is a bare spot on the wire to the sending unit, intermittently touching metal (ground) which will swing the gauge to high-pressure.

 

[PWC Repair]

The ground straps? I think there’s 2 ground straps, one behind the motor and one by the ac condenser. Are there any others i should take a look at and clean up? Thanks

I'm not sure if those are the only ones or not. I just know loose/dirty grounds can cause ALL sorts of issues.