updraft52

1998 grand cherokee 4.0, straight 6.

Have rebuilt the motor. 10/10 crank, new bearings, new cam w/bearings, new millings high volumn oil pump, when i start the engine no oil pressure...installed manual gauge shows no oil pressure...pulled oil filter, filter is full of oil...replaced new oil filter with a new different brand oil filter.....pulled timing cover cam gear checked plug in oil journal, everything looks right but still no oil pressure.....Does anyone have any ideas where to go from here i'm at my wits end.....

Bustedback

What was your bearing clearance? You did check it when you put the engine together, right? Did you prime the oil pump?

updraft52

10/10 bearings with 10/10 crank and i did prime the oil pump

Bustedback

How much clearance between the bearings and the journals? The spec is
.0015 to .003 thousands. Your 10/10 means nothing about the bearing clearance. It means the journals were turned down by .010", and the rods and mains were resized to match.

bigbadon

This means the pump is pumping oil and you at least have flow. Pressure is made by restriction to flow....SO, you have a big 'ol leak somewhere!
Is oil getting to the rockers?

andrewjohnson24

oil pressure sensor! replace it

Dr J

In a former life, I experienced a reputable shop leaving out a freeze plug out (in a Brit). Of course, with that, you'd see it on the floor like I did. Double check that the manual guage you are using is in fact a working guage. Double check that your replacement sensor is functioning properly. Good luck.

dave1123

You DIDN'T put a set if standard bearing in it, did you? Please tell us you used .010" undersized bearings.