A question about oil pressure...

[apollo]

Okay, so today I got my car out for the first time this year. The car has two oil pressure gauges - the stocker, and an autometer. When it fired up, boom, 45-50psi on the autometer, and right on the "M" in "Normal" on the stock gauge.

I went on a 15min cruise, and towards the end of my drive, while the autometer was still reading right on the line between 25 and 50 (so about 38psi then I guess), the stock gauge started to slowly fall, and act a little erratic. Like it slowly worked its way to the "R", then the "O", then to the edge of the "N" - but again, the autometer stayed the same.

When I pulled it in the garage and idled, the autometer dropped to 25psi.

Anyway, I don't see any reason why I should have an oil pressure issue, but I just wanted to run this by you guys to make sure this is more of an electrical fluctuation and not a mechanical problem.

[mustang8998]

Probably just the stock sending unit going bad. I would trust Autometer gauges way more than stock.

I wouldn't sweat it.

[Jeff88coupe]

Sounds normal to me...cold oil=more pressure, warm oil=less pressure. I wouldn't trust the stock oil pressure gauge at all...think of it as a on/off switch. What weight oil do you run?

[apollo]

I just run 5W-30. Motorcraft for now, maybe one a these days RP.

Yeah, I can't imagine an oil pump would slowly fail or something, but it just makes me a little nervous.

[facemelter71]

My 86 oil sending unit wire rubbed on the valve cover and send it straight to ground.The gauge pegged itself all the way to the red below the "N".

[mustang8998]

My 86 oil sending unit wire rubbed on the valve cover and send it straight to ground.The gauge pegged itself all the way to the red below the "N".

And I bet you went "OH SHIT!". :eek:

[85_SS_302_Coupe]

I read a long time ago that stock gauges on just about all cars are meant to measure more at the extremes than what's actually going on, or in other words they will read average most of the time no matter what temp you're running, but will show if you're really over heated or if you're cold. The reason is to not distract the driver from the road when changes occur. On my car the stock temp gauge always read on the hot side but it has never over heated.

[mustang8998]

I read a long time ago that stock gauges on just about all cars are meant to measure more at the extremes than what's actually going on, or in other words they will read average most of the time no matter what temp you're running, but will show if you're really over heated or if you're cold. The reason is to not distract the driver from the road when changes occur. On my car the stock temp gauge always read on the hot side but it has never over heated.

I think you just contradicted yourself. :dunno:

[facemelter71]

And I bet you went "OH SHIT!". :eek:

I hit the key and pulled off the exressway right by walmart near the Colerain exit on 275.I dont know how other people are but I check my gauges ALL THE FREAKIN TIME.I seen that oil PSI gauge Bury itself all the way to the red.Made my butt hole pucker,thats for sure.

[apollo]

I hit the key and pulled off the exressway right by walmart near the Colerain exit on 275.I dont know how other people are but I check my gauges ALL THE FREAKIN TIME.I seen that oil PSI gauge Bury itself all the way to the red.Made my butt hole pucker,thats for sure.

That had to be a scary moment for sure. Yeah I really do try to keep a close eye on all my gauges, which is why I start to get a little nervous when they act weird. I guess so long as the Autometer is reading good, we're okay.

What then is a good "normal" oil pressure for a 5.0? I mean at what point should I suspect a problem if the Autometer goes lower?

[85_SS_302_Coupe]

I think you just contradicted yourself. :dunno:

I don't mean it read that it was overheating, just a tad past dead center.