oil pressure problems

[GT_green_GT]

I did a full rebuild on my engine over the winter. Im a tech student and did it as part of my class. When the engine was removed it ran fine. Didnt burn oilor anything. I rebuilt it knowing that i had future plans for it and wanted it to be in good condition and wanted something to learn on. I fully rebuilt the engine. New bearings and rings. My cylinders were perfect along with every other part in the engine. I polished the crank and when i was done it looked brand new. I used clevite bearings and plastigauged them. The whole time my instructor was watching over. The cam bearings were replaced. I did not get into the oil plugs. The engine started and ran fine. Ive put nearly 700 miles on it since. i wanted to see how it ran after all my work. After i was done my oil pressure had dropped. anywhere below 1000 rpms the factory tach drops down to nothing. i thought maybe the oil thinned out. so since it was a rebuild i went ahead and changed it. I used supertech 10w-30. I noticed that the oil pressure is fine tell it is warmed up. then anything below 1000 rpms and it drops. im in the process of getting an autometer gauge to really see where the numbers are at. any one have any ideas?

 

[BlownFiveLiter]

You're wise in putting a real gauge on it. The stock one is basically useless, as I'm sure you'll notice shortly after the addition of the Autometer one. Mine's done that for years. A bad ground can do it, and can actually make it show its head a little worse since the factory ground is on the front cover, right next to the oil pressure sending unit.

 

[GT_green_GT]

so there is suppose to be a ground that goes to the front cover. is it that stud right off the side of it?

 

[True 5.0]

The ground strap that is important for the gauges is the one in the center of the drive side frame rail and runs down to the motor mount stud. Mine was disconnected and my gauges were all screwed up.

 

[JamesBaumann]

Mine does that exact same thing. Oil pressure will read fine and then once the car is fully warmed up and I am idling, the guage will drop all the way down to 0. im not really too concerned about it, I figure it is probably just the guage. Not to mention, when you are idling at around 600-800 rpm's, you probably wont have a lot of oil pressure anyways.

 

[True 5.0]

The factory pressure gauge is nothing more than a glorified idiot light. It DOES NOT read pressure. It is only "on" (needle at 12:00) or "off" (needle at 9:30). I do believe 15 PSI is the threshold.

 

[GT_green_GT]

all my other gauges are fine. especially with a fresh rebuild i shouldnt have oil issues. Im gonna get a autometer gauge as soon as possible and check out whats goin on.

 

[WhiteDevil]

With my 347 i installed an autometer oil pressure gauge. At cold start and under load i get about 50psi. When it warms up and is idling i get 26-27psi when warm under load it is at 50psi.

 

[GT_green_GT]

im not getting any noise or anything. its just that when u rebuild that and 700 miles later its doin that ya kinda freak out. seeing other poeple have similar problems its a stress reliever. my oil pressure kicks back in a cruising speeds.

 

[urban96]

i would make sure your ground is good, replace the stock oil pressure "switch" and throw the autometer on there for good insurance


did you reuse the stock pump or go with aftermarket?

 

[GT_green_GT]

regreting it....but the stock one