Oil Pressure Fluctuation

[blueguy]

So...when I start the car a little blue smoke comes out but nothing really after that. It'll sit around 50psi for a few miles but once she warms up I can watch it slowly drop...it gets scary low too...probably around 5-10psi when idling...which btw it is around 1200rpms since my IAC is bad...and I am kinda afraid to replace it and let it idle even LOWER IF I give it gas though like in traffic, off from a stop light it'll go back up to almost 40-50psi, but slowly drop back down. There are no visible oil leaks coming from anywhere either. Granted I haven't check the oil pan...gonna do that tomorrow. Any ideas guys? She runs fine otherwise...no SES lights except for my IAC and No Converter codes. Could a bad seal on my valve covers cause a loss in oil pressure? I can pop those on and off really quickly so that would nice if it is a possibility. I have a video but it is over 100MB which is too big for photobucket...gonna try to get a shorter clip today.

TIA guys!!

btw...WAHOO!! 2,000 posts

[Bio248]

my car idles at 10 psi with running 10w-40. 10psi for every 1000 RPM, that is the rule.

[minichopper6hp]

Thought we already went over this.... The SPEC for the 3800 is 60psi @ 1850RPM. If you do not have that, then you have either a bad pump, bad bearings somewhere, or a bad pressure relief spring for the oil pump. Do not drive that motor with that oil pressure, youre going to kill it.

[blueguy]

Well...it's odd...changed the oil/filter...which I WASN'T low on...and now it idles at 50 or so...drops to about 30-40 when I put it into gear but everything else checks out...damn car...I'll let you guys know how she does on the road.

[minichopper6hp]

are you using a mechanical gauge?

[blueguy]

are you using a mechanical gauge?

Hell no...no way I am running a oil line into my interior

[Zef_66]

Well...it's odd...changed the oil/filter...which I WASN'T low on...and now it idles at 50 or so...drops to about 30-40 when I put it into gear but everything else checks out...damn car...I'll let you guys know how she does on the road.

What oil/filter were you running before? How many miles/months on oil/filter. What oil/filter are you running now?

[minichopper6hp]

i doubt the accuracy of electric gauges.... that could be your problem

[Bio248]

if you have 10 psi of oil pressure at idle there is nothing wrong with your car. if youre really worried about it run a higher weight oil.

[minichopper6hp]

theoretically, 10psi should be fine but on these motors, run high oil pressure. if you see less than 40psi at idle, there is something wrong.

[Sabrewings]

I've seen old oil do what bluegtp was describing. It breaks down as it ages and its viscosity drops like a rock as it warms up. It becomes incredibly thin warm and the oil pressure thus drops. Oil change is all it needs.

Not sure what oil he's running, but it could be a sign of crappy oil.