I just finished rebuilding my 2006 4.7. It started right up but it is not building up oil pressure like it should. I replaced all bearings and oil pump. It is pumping oil but the top end is noisy and the oil light stays on. Any ideas what is wrong. I have rebuilt many engines through the years; this is my first 4.7 to work on.

 

How do you know if the oil is pumping if it is not building pressure, the oil light is on and the top end is making noises? Sounds like it is not pumping to me. I personally would not run it long like that. Perhaps the pickup tube fell off, or the screen is clogged? The opil light/pressure gauge could be a sender, but the top end making noise sounds worse.

 

First thing I'd do is put a mechanical gauge on and see what the actual oil pressure is. Run the engine only long enough to see what the o-p is. (You may have a dry bearing/journal someplace.)

Your 4.7 is an DOHC, right? Lots of bearings and journals & just one bearing put in wrong would screw up your oil pressure. Did you get a reground crank? Stupid question I know, but were the bearings matched to the crank? Did you check your clearances with Plastigage? Sorry to suggest it, but you either cut a corner and got caught, or you made a mistake. In the end, I think you're gonna have to pull the engine back out and check your crank, rod, and cam bearings.

Been there, done that, BTW. When learning to build engines, any dumb mistake that could be made, I made it.

 

I'm new at this so if I post twice please forgive me. # 6 rod bearing shed a large section of the face metal. The machine shop checked, and polished the crank, all journals checked good. They supplied me with new standard rod and main bearings. Yes I did check clearance with plastigage. I did remove the pan and checked the pickup tub; ok there. I removed the pump and checked it specs, all checked ok. Before putting the timing chain cover back on I cranked the engine over and lots of oil flowed from the heads. With the valve cover off there was oil there. I have not checked the oil pressure with a mechanical. I plan to do that tomorrow. If I find what I expect I will replace the pump. After leaving the farm my first job was in a machine shop rebuilding engines lots of them, but that was in 60's.

 

Any chance it might be a bad check valve (in the oil filter?) I once put a main bearing shell in backwards. The oil hole from the block to the bearing was blocked (that one was a disaster.)

Sounds like you have a handle on knowing your way around an engine--keep us in the loop.

 

Many years ago I was taught that any time I work on an engine, oil pump, camshaft, or bearings etc, ALWAYS connect a test gauge, spin it over w/the starter and check for good oil pressure BEFORE starting it.

 

I've always primed them with a drill before putting the distributor in (which I realize would be kind of difficult on a 4.7).