Is this an oil pump issue?

[moparzrule]

My fresh rebuilt engine has 200 miles on it. For the first 150 miles, by 3000 RPM I would have 65 PSI oil pressure (65 is the pop off pressure for the oil pump I guess). Now it won't really go above 40 PSI except when the engine is cold it will go to 50 PSI. Even at 6000 RPM it stays at 40. But, it gets to 40 PSI by 2500 RPM and still has 15 PSI at hot idle which are both exceptional.
I plastigaged all my clearances and they were closer to minimum spec rather than max.
I just changed my oil, I did not see any metal in the old oil.
So I'm wondering if the standard volume melling oil pump I got from autozone is a piece of crap? Any opinions?

[CSXT802]

Maybe it lifted the relief and did not re-seat.

[moparzrule]

maybe... Any other opinions?

[CSXT802]

is this a mechanical Gage or electric.?

[minigts]

Do you have any comparisons to a stock gauge, like where 40 psi would be? The reason I ask is that I have what seems to be very good oil pressure that sits just to the right of the middle on a stock gauge when over 2000 RPM and middle to left of middle from 2000 RPM and lower. When above 3500, it's 2-3 bars to the right of middle. At start up, it's at the long bar just before the high pressure warning. Not sure if that is valuable or useful. :\

[turbovanman²]

How are reading the oil pressure? What oil filter did you use?

Melling are fine, thats all I use, have one in the TIII, 25 psi at idle, 75 at 3000 rpm using Mopars heavier spring kit. Using an electric Autometer guage.

[1985ShlbyChrger]

moparzrule would be using a aftermarket gauge, he HATES any kind of stock oil pressure gauge. I would assume it's mechanical.

I am thinking it is the relief also. I probably got stuck and won't allow it to build any more than 40 psi.

[moparzrule]

Yes it's just a mechanical 100 PSI oil pressure gauge, my shadow doesn't have a stock oil pressure gauge in the cluster so I don't know about that. And yes it's true I hate all stock gauges, never rely on them!

Looks like I need to replace this POS oil pump....grrrrrr. Or I'm assuming I could just use the mopar spring kit correct? Where do you buy yours from simon and how much was it?

[moparzrule]

Oh and I'm using a mobil 1 oil filter BTW along with castrol GTX 10W40 oil.

[butchsuppe]

May be leaking between pump + block. 15psi at idle is still good.

[moparzrule]

I torqued that bolt to the proper spec. Was there suppose to be a gasket there? Like I said for the first 100-150 miles the oil pressure was great, would shoot to 65 PSI by like 3000 RPM. Perhaps it rattled loose some? But I'm still suspecting the relief inside the oil pump...

Last time I had issues with oil pressure I had rod bearing failure, BUT it also had low PSI at idle which I'm not having now so this is why I'm suspecting the pump itself being the issue. Oh and last time I had issues with oil pressure I had metal in the oil when I drained it.

[moparzrule]

Going to buy the hi pressure spring from Mopar....I just hate so much that I have to drop the oil pan with 200 miles on the rebuild

[Turbodave]

I torqued that bolt to the proper spec. Was there suppose to be a gasket there?

Pretty sure the FSM calls for anerobic sealer between the pump and the block.

[turbovanman²]

I use anerobic between the block and pump, just for safety. 65 psi at idle is theortically impossible as the pump isn't spinning fast enough to produce that kind of pressure, thats why the relief valve, so when yuo get the rpms up, it opens, venting the excess oil flow. 15 psi at idle is still more than perfect BUT if only 45 psi now, it could be the relief valve is sticking or stuck as that will cause low rpm pressure.

[turbovanman²]

moparzrule would be using a aftermarket gauge, he HATES any kind of stock oil pressure gauge. I would assume it's mechanical.

I am thinking it is the relief also. I probably got stuck and won't allow it to build any more than 40 psi.

If the relief valve got stuck, it wouldn't build up pressure or it would peg the guage.

[moparzrule]

And the winner is.........Oil pump flange not completely seated to block causing an oil leak in between.

I did torque those bolts exactly to 21 ft/lbs, BUT, there was crud in the threads of the one bolt hole apparently giving a false torque reading. This is what happens when you overlook running a tap through every single bolt hole in the block before assembly. You've been warned. LOL

[Captain Chaos]

And the winner is.........Oil pump flange not completely seated to block causing an oil leak in between.

I did torque those bolts exactly to 21 ft/lbs, BUT, there was crud in the threads of the one bolt hole apparently giving a false torque reading. This is what happens when you overlook running a tap through every single bolt hole in the block before assembly. You've been warned. LOL

HAHA. Nice. At least it wasn't something more serious. I did however put the MP spring in my stock Melling to get the oil pressure up to where I felt more comfortable.

[moparzrule]

Yup, since the oil pump itself wasn't an issue I did indeed put the mopar spring in.

New oil pressures all with engine completely warmed up-
idle-13 PSI
2000 RPM-30 PSI
3000- 45 PSI
4000-60 PSI
5000-75 psi

Thats about all I made out. Above that I kinda needed to watch the road LOL. All I know is it was above 80 PSI anyway. I think it's popping off at about 85 PSI. I like that it bumps up 15 PSI per 1000 RPM.

When I first started it up cold idle it went right to 90 PSI LOL. Rev it to 2000 and it pegged my 100 PSI gauge!

[turbovanman²]

Thats good, luckily you didn't damage the intermediate and oil pump gear. I had one come in where the guy didn't seat the pump and cranked the bolts down, destroyed both gears,

[moparzrule]

Ouch.

Nope, both gears looked like the day I put them in

Now as soon as I finalize a few tweaks in my calibration I'm gonna throw your super 60 roller cam in this bad boy. That will probably happen some time saturday.