I have put together an LQ4 bored out to a 6.2L. I have a melling 295 oil pump on it, I have replaced the oil sending unit twice, replaced the oil, all of the pick up tube pieces, all o rings are new, the engine has less than 20 miles on it. When it gets warm, i lose all oil pressure. At start up, I have 30 psi no problem and up to 45/50 under acceleration. When I lose oil pressure (it doesn't just drop, it hits zero on the stock gauge) if i give it a little gas, it will jump up to 10/15/20 psi. I am upgrading the pump to see what affect that has. Crank and rods are stock/used L92, cam is aftermarket. All clearances are stock and checked. All bearings brand new. I did not do the rebuild myself so if anyone needs any more information that think might help figure out a possible route to take, let me know and I will check into it. HELP PLEASE.

 

I saw this once, and the build thread is on here. Guy bought a nice, new 434 short block and the barbell wasn’t installed. Had very similiar symptoms as yours. Do you have the correct tool to cut your oil filter open and inspect the media?

 

is there a way he could jack the car up, remove the filter, and stick something up the oil galley to see if you feel barbell? i dont remember what mine looked like apart if this would be possible

 

http://www.superchevy.com/how-to/eng...l-parts-guide/

see the plug behind the timing cover and barbell in this article. make sure both are installed

 

yes but his motor is in the car. a hell of a lot of work to do only to find out the barbell is there

 

well he's upgrading the oil pump so he can at least check the front plug under the timing cover while in there. not sure about an easy check for proper barbell installation. another note is the barbell needs to be put in the correct way

 

I personally don't like electronic oil pressure gauges. I was out cruising one evening and looked down and saw zero oil pressure. I though my heart stopped for a moment but it turned out to be just a bad connection to the sender. I've since installed a hard line off the sensor location on the valley cover which allows me to run a mechanical gauge and my blood pressure has been doing much better.

 

I don't see how you'd have any oil pressure at all without the barbell.

 

I think the barbell makes sure the oil goes thru the filter before going to the bearings, etc.

 

It also stops oil from just shooting out the back of the galley into the rear cover right? I don't think there is alot of clearance between the barbell and the rear cover, but it is the barbell that seals that hole.

 

TRUE!! lol. If it's missing that's exactly what will happen. I was speaking mainly about its actual function.