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Let's get to the bottom of the oil pressure issue, before getting in to deep.
Remove pan, check o-ring on pick up tube and inspect tube...if good...remove one rod bearing cap (preferably number eight) and see if it's worn or crank journal is damaged...if good, reinstall (torquing to correct specs)...then look up at each cam bearing and see if any have "walked/moved" out of their correct position in the block...if good...remove oil pump housing. If any of these steps result in a fail, you need to decide what steps must be taken. Yes, the o-ring is an easy one...but the rest are costly.
Also, what are the folks saying where you bought the engine from? You are, or could, have a boat load of money and time into this engine...what are their thoughts on that? Are they going to compensate you? Don't know what you paid for it, but your repairs could exceed your original purchase price...especially, if the engine was ran out of oil to begin with (and that's why it was at the junkyard) and it needs rod/main/cam bearings and upper end work. You need to decide whether or not you want to proceed with such an endeavor. Face it, you expected a running engine...that's what you paid for...do you really want to rebuild any engine you've never heard run? Because, unless you have some serious mechanical skills...you could miss certain things during assembly that could result in other issues down the line.
Not try to be rude, but if l would have pulled that oil pan and seen that rubber piece...there is no way l would have assumed it was the total issue. Like mentioned previously, you can see area around the rubber piece, plenty of room for oil to be drawn. Sure, it could have caused the oil pump to fail...but, l would have keep looking. These are the type of things you need to be fluent in, while doing diagnostics on an engine. Or...post pictures along every step and wait for folks here to help you out.
In my opinion, you have too seriously consider whether or not to move forward on this engine.
Good luck.
Brian.
Last edited by The Deputy; 10-13-2018 at 05:10 AM.
I took pickup tube off while I had the pan off the first time. It was good and the O ring was in great shape.
I took everything off to be ready for the pan and cover pull tomorrow afternoon.
I intend to contact the seller Monday after I know if the oil pump is bad etc.
I will pull #8 rod tomorrow and post a pic.
Didn't see any mention of removing pick up tube in posts #14 & #18...you've been pretty thorough about what you've done and tried...so, when l didn't see it mentioned...well...figured you just bypassed it.
If o-ring was good, my recommendation at that point would have been to remove front cover...or call supplier and have a heart-to-heart discussion with them about what to proceed with...they might not be to "cool" with you disassembling it...and may try to blame this issue on you. Don't dismiss the last portion of that statement, because l've seen/heard of it more times than you can shake a stick at it.
It will be really interesting to see what you find, especially, since they said it ran fine.
Got the front cover off
oil pump gears looked and felt good.
Got the oil pressure bypass valve off and the spring came out but not the little plug.
Once I fiddled with it and got it out .... oil started flowing!!!!
I think it was just stuck. I could have probably done the same thing with a light tap of a hammer without tearing it down.
If the bypass valve valve was stuck and not allowing g oil in that should explain the issue ..... right?
Bypass valve is not your problem, it only functions to bypass the filter, the engine is downstream of that and creates the resistance necessary to have oil pressure. The bypass valve is on the filter side of the front cover, pressure relief valve is on the drivers side. Which valve did you remove? Where was it stuck? Bottomed or at the top of the tube?
I don't see any problems based on the pics.
The oil pump is very efficient and will actually work even rotating by hand, with it back on you can pull a cooler plug to make sure you are getting flow. You can also gravity prime through the removed plug, once rotating oil should pump out. Remove the spark plugs to make it easier. Once you have oil flowing, it should have oil pressure when running, even if it does have a walked cam bearing (oil pressure will be low if it has a walked cam bearing). If you do the LS series engine style air over oil pressure priming, you can actually get a oil pressure reading before firing the motor. The air over oil priming actually simulates the oil pump. Valve covers and intake gasket off you can actually visually see the oil flowing out around the cam bearings and rocker arms.
This is still a mystery for me, I have not seen anything yet definitive. Given you bought the motor used, fired it up, and it wasn't making loud knocking noises I wonder what caused the initial problem. Usually only mechanical failures cause loss of oil pressure.
The valve that was “stuck” in my opinion was on the drivers side. I also took out the filter side valve and cleaned everything before putting them back in.
I also have an oil pressure guage now so I will manually check it. Reinstalling everything now but have to go buy more before I can fire it up. Might be tomorrow before start up.
10-13-2018, 05:00 AM
