Oil Pressure Gauge - Bad Sender or Signal

[stkjock]

So had the car out this morning. Cruise out to meet my buddies at the Sunday spot all is good, stop the car, get back in a few mins later fire up and the Autometer Pro-Comp gauge starts showing about 28 psi at idle, a bit low.

Not worried - figure oil is hot so reads a bit low. Start driving and the pressure moves to 40 or so and hits 60 above 2000.


Drive a bit more and the needle starts jumping around, 20 - 40 - 20 - 60 - 20 etc.


Holds at 25-28 for a bit, then starts to hold at 10-12, no I start to worry, but the factory gauge is still at 2/3 towards high, like always.

Get to where we're going park the car, let it sit, check the oil level, spot on.

Start the car up about an hour later. Oil pressure now reads 10-12 psi on the Autometer, factory gauge still normal.

After about 5 mins or so, Autometer drops to zero, factory still normal.

Motor sounds fine and car is running like normal.


so my first thought is the sender failed or it's electrical. I have not looked under the car yet.


Thoughts?

Thanks

 

[Rasmus]

Measure continuity/resistance in wiring. If good, check the sender. If still bad, replace gauge. I'm guessing it's the sender.

 

[stkjock]

well after some added internet searching, seems it's a common issue for the sender to go bad when it's attached directly to the motor, vibrations kill them.

Spoke to Autometer and they have updated the design to help them live.

ordered a new unit today.

 

[86GT351]

I was going to say Sender. Common issue!

 

[ksack]

Slightly off topic, but my Autometer sender unit works great with the gauge but the computer hates it and says I have low oil pressure when the revs drop (normally during deceleration). It worked fine for the first 4-5 months it was on then the computer started acting up. I just ignore it but I'd love to not have it beep at me. Any ideas?