prestonztt

So I just rebuilt the engine about 3 days ago and have a few questions. Well when the old motor was in it, the stock oil pressure gauge would drop when I get on it and then come right back up when I just stared to cruise. Well the new engine is doing the same thing now. I used the old oil pump out of the old engine in the new. It looked pretty good but maybe its the problem.

Tonight I got on it and the oil pressure dropped all the way down on the stock gauge. Its doing the same exact thing as the old engine was doing. I dont know if the stock gauges are junk or what. I know that I need to get an aftermarket one.

I mean when I pulled the engine apart, the car wasnt knocking or anything. The bearings looked pretty good. Just a little copper was showing on some of them, but thats it.

Im thinking about just hooking up a real oil pressure gauge and just testing it and actually see.

I didnt know if anyone else had the kind of problems or not. Just seeing if I could get some ideas from you guys.

mattdel

I got a high volume pump for sale...

but before u do anything, get a real gauge on there.

rmodel65

you used the old pump in the new motor wtf....if your gonna spend money do it right

67mustang302

Seriously, oil pumps are one of the cheapest parts in an engine rebuild, yet arguably one of the most important. What are your bearing clearances...and how do you know the pump was good, did you check the pump clearance?

prestonztt

Yeah, I know. Trust me, I wish I would have done it so I could cross it out.

Yep, It just looked pretty good as well as the sump. I didnt plastigauge anything so I wouldnt know honestly. I wish I would have done all this now.

But here is a video of the factory oil pressure gauge that I just took.

http://www.youtube.com/watch?v=3s1rZUtcZ7A

mattdel

If you're running a high volume oil pump, its possible that it's sucking the pan dry as you increase RPM. If not, your bearing clearances are probably too high, and you should look into a 15-40 or a 20-50 oil.

Do not add more oil to compensate for this. You will aerate the oil and create more windage, and suffer even lower PSI.

67mustang302

A HV pump won't suck the sump dry. Sucking the sump dry is an oil return issue to the sump, not a pump issue. Or it's an excessive bearing clearance issue causing oil to be thrown out of the rods faster than it can return to the sump(which is also an oil return issue).

He either has a pump or a bearing clearance issue, and since he didn't measure either one it's impossible to tell.

prestonztt

It was the sender. I took the plug off and cleaned the connections and it doesn't drop anymore.

Bubba 95SN

Gee, that was some kinda funny joke you played on us. New motor-old oil pump-good one. I am still chuckling.