Thread: No oil pressure after engine swap please help!

Hello everyone. I am new to the forums but plan on becoming more and more active, I've found this forum very helpful in the past. Anyways, to the point. I just swapped a 3800 Series 2 NA from a 99 Lesabre into my grand prix, after my old engine spun a rod bearing. After we got it running, I noticed the Oil pressure light would not turn off. I didn't hear anything in the bottom end but the lifters in the top end were rattling away. I did switch the oil filter adapter due to the engine mount, so the regular grand prix filter adapter is on the block. I read somewhere that I could prime the pump (its been sitting at the wreckers for who knows how long) by adding a few extra quarts and running it for a few moments. I did that, and noticed no change. So i pulled off the oil filter and discovered it was dry. I filled the filter and stuck it back on in hopes that would help prime the pump. Fired it back up and ran it, and still ticking away in the top end with the light on. I pulled the filter once again and noticed the filter was empty (so the pump is obviously sucking the oil). I then pulled the filter adapter, but there wasnt a drop of oil in the channel leading to the filter. What could it be? Something in the pick up line or screen? how do I solve this without pulling the pan? ( I dont wanna lift the engine again...) =[
any help would be much appreciated. It is also throwing a code for a high value reading from the MAP sensor, if that would possibly relate in any way to this issue. Thanks in advance!

44 views and no one has an answer? =[

hasn't been that long really.

But is the bypass valve and spring still in the front cover behind the oil filter adapter?

Originally Posted by BillBoost37

Typically to prime, I disconnect the ICM connector and crank the motor for a few seconds two or three times.

Since you aren't seeing any pressure, the pump is probably not pulling oil. This means you'll need to pull the cover and fill the pump with vasoline to get it working.

Unless you put the filter adapter together wrong? Spring in first, then cup of plunger over spring, gasket and filter adapter.

it did suck the oil filter dry after i had primed it though, so my thoughts is that the pump is working. and the spring and plunger were out, i let my buddy put them back in though... he put the plunger in the block first, with the flat side in, then set the spring in the cup of the plunger and set the other end of the spring in the middle cavity of the filter adapter and bolted it down...
is that correct?

Originally Posted by BillBoost37

It's in wrong. Don't turn it over again until it's fixed.

Block, spring, cup of plunger over spring, , gasket, oil filter adapter

thank you so much. ill see if i can dig the plunger out of there with a magnet or something...
thanks again.

problem has been solved. the pressure valve was indeed in wrong. flipped it around, new gasket, and the lifters quietened almost instantly, and the light has not returned since. thanks for everyone's input!
for anyone else who needs it, the correct way is the spring goes into the center hole first, then the plunger, open side in in which that it seats the spring, and then the gasket and housing. thanks again!

Glad you got it fixed. Assuming all the mechanical parts were put together correctly, my first question to you would have been what brand and weight of oil was in it upon the first startup. No need for that now, though.

still running with no oil related problems!
and i used just cheap quaker oil and fram filter, just to get everything moving and flushed, and im gonna change the oil after about a week and then continue with regular maintenance intervals.