L P C

we just rebulit the engine and used a ported oil pump and when we fired it up we had 5-15 lbs of pressure, so we replace the sending unit same thing, so we replaced the oil pump again and used a new seal still same thing. what are we missing

Jabroni

Did you crimp/destroy the rubber O-ring in the pickup tube when you swapped it to the new pump?

DaddySS

Start with very carefully checking the oil pickup, pump etc. There are many things that will cause low oil pressure. Did you replace main and rod bearings?

VSGLS1

iTrader: (8)

What are the bearing clearances?

L P C

new stock crank and bearings, replaced oring with pump and made sure it wasnt pinched

VSGLS1

iTrader: (8)

You using a stock timing set? Was this a new block? Was the block at a maching shop? Was the plastic oil "plug" in the pass rear of the block in before you put the rear cover on?

L P C

no its a billet master double roller and the block was brought to me and it came from the machine shop and im not sure about the plastic plug so its going to be a long day

strokedls1

iTrader: (1)

You didn't check clearance on any of the bearings before final assembly. If the plug in the back is not in you should have zero oil pressure. Does the pressure increase at all with rpm? Did you pack the oil pump with any grease before installing it?

crainholio

iTrader: (2)

What was the measured clearance for each main and rod bearing? Using all new stuff is fine, but you'd still want to measure before final assembly.

Also, what did you torque the mains and rod caps to?

Demon SS

iTrader: (3)

are you going by the oil gauge in the car or did you check the pressure with an external gauge?
a ported oil pump will sometimes cause a lower idle oil pressure, remember a bigger opening will allow more oil flow but less oil pressure at idle

VSGLS1

iTrader: (8)

Did the oil pump have a spacer and was it installed correctly? This would have come with the timing set.

L P C

yes we used the spacer on the oil pump and we are going by the guage in the car, also the friend that brought it to me says that the oil pressure dropped like this before he lost the #1 bearing , could it be something in the oil passge way and how do i check for this

crainholio

iTrader: (2)

Since you're not answering the bearing clearance questions, I'm guessing you didn't measure them.

A blockage downstream of the pressure sensor would actually increase indicated pressure, right up until the engine let go. As for a blockage upstream of the sensor, there's just the oil pickup tube, the pump, the filter, and the block castings between them.

I'd pull the oil filter and cut it open, inspect the filter pleats for metal flakes. They make specialized cutters, but you can punch a hole in the cannister and use snips or side-cutters to open it up.

2001 Pewter WS6

iTrader: (43)

did you replace the cam bearings???

Ryan K

iTrader: (11)

Um, NO. A ported oil pump should have ZERO effect on oil pressure unless the spring/plunger are sticking open. Porting the oil pump does not affect the volume of the pumped oil at low RPM, same volume flowing to a the restriction (the bearings) same pressure. Porting the oil pump only affects high rpm volume due to the lower flow loss in the restriction of the outlet causing oil to push the plunger open.

There are four possiblities:
1. Air being sucked into the oil pump due to a bad o-ring
2. Oil escaping the oiling system prior to reaching the bearings
3. Bearing clearances too large.
4. Oil Bypass in the pump sticking open.

Ryan

Boostaholic

iTrader: (4)

You should check your oil pan gasket, if you did not replace it, then odds are it is too crushed in the fliter area and not making a good seal.

When this happens, oil will leak past the gasket and back into the pan.

Race Car Driver

The problem could be totally unrelated to the oil pump. Just for example, main bearing clearances could be too great, or . . .