Oil pressure gauge reading 80

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nogayford420

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Your oil pressure sending unit is most likely bad.
Best way to check is turn the key to the on position but do not start the engine. If the gauge goes to 80, it is a bad sender.
Not horrible to replace... not fun either. Yes you can drive like that if it is the sender.
It is a short to ground in the sending unit. Mine did it last summer. Fail open is 0, fail short to ground is 80. You can check this by just turning the key on but not starting the engine. The dash will do the gauge sweep then oil pressure should go full 80 if it is a bad sender. Because if the engine is not running and you have pressure it can only be the sender.
What if it goes to 40 with the key on then 80 with the engine running? Just replaced the sending unit, it worked for a couple days and now this is happening. Before it would just go to 80 with the key on and stay there. Thinking about getting in there with my power probe somehow and seeing if i can learn something.

Should I just return the sending unit and get a new one? It's a duralast. 2003 tahoe btw
 

nogayford420

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What if it goes to 40 with the key on then 80 with the engine running? Just replaced the sending unit, it worked for a couple days and now this is happening. Before it would just go to 80 with the key on and stay there. Thinking about getting in there with my power probe somehow and seeing if i can learn something.

Should I just return the sending unit and get a new one? It's a duralast. 2003 tahoe btw
the old (new) one was burnt at the connector and it seems the signal wire pin is melted a little on the pigtail, have 5volts at one pin ground at the other and the signal wire (bottom, the one by itself) shows no voltage nor ground but has a high resistance reading. Thoughts? I put the new sensor in but didnt plug it in so i can still drive
 

Sam Harris

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Definitely go with OEM. I replaced mine 4x (3 of which were AC Delco parts), before I got one that actually lasted more than a couple months. The store brand one actually spectacularly failed, and caused low oil pressure, as it sprung a leak!
 

2006Tahoe2WD

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Happened to me again after 3? years. I don't recall if I used OEM.
Yesterday I picked up a new sender at the dealer - $112.
Turning on the key and not starting makes too much sense - I'll do that this morning.
As mentioned it is not an easy replacement - but doable and yes you will need to laydown on the engine. I must have the socket that works somewhere, since I've done it before.
 

2006Tahoe2WD

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Happened to me again after 3? years. I don't recall if I used OEM.
Yesterday I picked up a new sender at the dealer - $112.
Turning on the key and not starting makes too much sense - I'll do that this morning.
As mentioned it is not an easy replacement - but doable and yes you will need to laydown on the engine. I must have the socket that works somewhere, since I've done it before.
Okay new sensor installed. Now reading like "normal" 40psi.... I didn't like the feel of trying to torque to 22 lb-ft so I stopped without a click. I'll check back later re. oil leaking out.
 

blondie70

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When we had the engine out for the cam job...I modded my oil pressure sender by using a grease gun hose and the fittings to adapt it to a sender. Also increased the length of the sender wires....now my sender is laying right on the intake manifold. Can change it easily if need be.
 

2006Tahoe2WD

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When we had the engine out for the cam job...I modded my oil pressure sender by using a grease gun hose and the fittings to adapt it to a sender. Also increased the length of the sender wires....now my sender is laying right on the intake manifold. Can change it easily if need be.
Now that's thinking ahead.
 

ivin74

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When we had the engine out for the cam job...I modded my oil pressure sender by using a grease gun hose and the fittings to adapt it to a sender. Also increased the length of the sender wires....now my sender is laying right on the intake manifold. Can change it easily if need be.
I would like to see some pictures. That is one mod I have not thought off.
 

blondie70

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I will try to get a pic or two soon.
The main thing on this is to find the fittings. Bushings from hose to truck...from hose to a coupling that is put onto the sensor. I forget the thread size of the truck/sensor but think the hose was 1/4" NPT and about a foot long. Fittings easy to get off e bay.
 

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