Oil pressure gauge reading 80

[nogayford420]

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]

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]

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!